diff options
| author | garhve <git@garhve.com> | 2022-12-20 11:04:25 +0800 |
|---|---|---|
| committer | garhve <git@garhve.com> | 2022-12-20 11:04:25 +0800 |
| commit | 369d11587339ce74f8ebc76f2607fe55545eaf7d (patch) | |
| tree | 4b25c6f7e3aca08a90b25950f4f8e4430c4294bc /rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand | |
| parent | 0f1b6d015243e55a38b1c1b7e8af66668e4e794d (diff) | |
Build small project following the book
Diffstat (limited to 'rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand')
23 files changed, 16569 insertions, 0 deletions
diff --git a/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/bernoulli.rs.html b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/bernoulli.rs.html new file mode 100644 index 0000000..8b882e8 --- /dev/null +++ b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/bernoulli.rs.html @@ -0,0 +1,441 @@ +<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/home/pico/.local/share/cargo/registry/src/github.com-1ecc6299db9ec823/rand-0.8.5/src/distributions/bernoulli.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>bernoulli.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" 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src="../../../wheel.svg"></a></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> +<span id="2">2</span> +<span id="3">3</span> +<span id="4">4</span> +<span id="5">5</span> +<span id="6">6</span> +<span id="7">7</span> +<span id="8">8</span> +<span id="9">9</span> +<span id="10">10</span> +<span id="11">11</span> +<span id="12">12</span> +<span id="13">13</span> +<span id="14">14</span> +<span id="15">15</span> +<span id="16">16</span> +<span id="17">17</span> +<span id="18">18</span> +<span id="19">19</span> +<span id="20">20</span> +<span id="21">21</span> +<span id="22">22</span> +<span id="23">23</span> +<span id="24">24</span> +<span id="25">25</span> +<span id="26">26</span> +<span id="27">27</span> +<span id="28">28</span> +<span id="29">29</span> +<span id="30">30</span> +<span id="31">31</span> +<span id="32">32</span> +<span id="33">33</span> +<span id="34">34</span> +<span 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License, Version 2.0 <LICENSE-APACHE or +// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +</span><span class="doccomment">//! The Bernoulli distribution. + +</span><span class="kw">use </span><span class="kw">crate</span>::distributions::Distribution; +<span class="kw">use </span><span class="kw">crate</span>::Rng; +<span class="kw">use </span>core::{fmt, u64}; + +<span class="attribute">#[cfg(feature = <span class="string">"serde1"</span>)] +</span><span class="kw">use </span>serde::{Serialize, Deserialize}; +<span class="doccomment">/// The Bernoulli distribution. +/// +/// This is a special case of the Binomial distribution where `n = 1`. +/// +/// # Example +/// +/// ```rust +/// use rand::distributions::{Bernoulli, Distribution}; +/// +/// let d = Bernoulli::new(0.3).unwrap(); +/// let v = d.sample(&mut rand::thread_rng()); +/// println!("{} is from a Bernoulli distribution", v); +/// ``` +/// +/// # Precision +/// +/// This `Bernoulli` distribution uses 64 bits from the RNG (a `u64`), +/// so only probabilities that are multiples of 2<sup>-64</sup> can be +/// represented. +</span><span class="attribute">#[derive(Clone, Copy, Debug, PartialEq)] +#[cfg_attr(feature = <span class="string">"serde1"</span>, derive(Serialize, Deserialize))] +</span><span class="kw">pub struct </span>Bernoulli { + <span class="doccomment">/// Probability of success, relative to the maximal integer. + </span>p_int: u64, +} + +<span class="comment">// To sample from the Bernoulli distribution we use a method that compares a +// random `u64` value `v < (p * 2^64)`. +// +// If `p == 1.0`, the integer `v` to compare against can not represented as a +// `u64`. We manually set it to `u64::MAX` instead (2^64 - 1 instead of 2^64). +// Note that value of `p < 1.0` can never result in `u64::MAX`, because an +// `f64` only has 53 bits of precision, and the next largest value of `p` will +// result in `2^64 - 2048`. +// +// Also there is a 100% theoretical concern: if someone consistently wants to +// generate `true` using the Bernoulli distribution (i.e. by using a probability +// of `1.0`), just using `u64::MAX` is not enough. On average it would return +// false once every 2^64 iterations. Some people apparently care about this +// case. +// +// That is why we special-case `u64::MAX` to always return `true`, without using +// the RNG, and pay the performance price for all uses that *are* reasonable. +// Luckily, if `new()` and `sample` are close, the compiler can optimize out the +// extra check. +</span><span class="kw">const </span>ALWAYS_TRUE: u64 = u64::MAX; + +<span class="comment">// This is just `2.0.powi(64)`, but written this way because it is not available +// in `no_std` mode. +</span><span class="kw">const </span>SCALE: f64 = <span class="number">2.0 </span>* (<span class="number">1u64 </span><< <span class="number">63</span>) <span class="kw">as </span>f64; + +<span class="doccomment">/// Error type returned from `Bernoulli::new`. +</span><span class="attribute">#[derive(Clone, Copy, Debug, PartialEq, Eq)] +</span><span class="kw">pub enum </span>BernoulliError { + <span class="doccomment">/// `p < 0` or `p > 1`. + </span>InvalidProbability, +} + +<span class="kw">impl </span>fmt::Display <span class="kw">for </span>BernoulliError { + <span class="kw">fn </span>fmt(<span class="kw-2">&</span><span class="self">self</span>, f: <span class="kw-2">&mut </span>fmt::Formatter<<span class="lifetime">'_</span>>) -> fmt::Result { + f.write_str(<span class="kw">match </span><span class="self">self </span>{ + BernoulliError::InvalidProbability => <span class="string">"p is outside [0, 1] in Bernoulli distribution"</span>, + }) + } +} + +<span class="attribute">#[cfg(feature = <span class="string">"std"</span>)] +</span><span class="kw">impl </span>::std::error::Error <span class="kw">for </span>BernoulliError {} + +<span class="kw">impl </span>Bernoulli { + <span class="doccomment">/// Construct a new `Bernoulli` with the given probability of success `p`. + /// + /// # Precision + /// + /// For `p = 1.0`, the resulting distribution will always generate true. + /// For `p = 0.0`, the resulting distribution will always generate false. + /// + /// This method is accurate for any input `p` in the range `[0, 1]` which is + /// a multiple of 2<sup>-64</sup>. (Note that not all multiples of + /// 2<sup>-64</sup> in `[0, 1]` can be represented as a `f64`.) + </span><span class="attribute">#[inline] + </span><span class="kw">pub fn </span>new(p: f64) -> <span class="prelude-ty">Result</span><Bernoulli, BernoulliError> { + <span class="kw">if </span>!(<span class="number">0.0</span>..<span class="number">1.0</span>).contains(<span class="kw-2">&</span>p) { + <span class="kw">if </span>p == <span class="number">1.0 </span>{ + <span class="kw">return </span><span class="prelude-val">Ok</span>(Bernoulli { p_int: ALWAYS_TRUE }); + } + <span class="kw">return </span><span class="prelude-val">Err</span>(BernoulliError::InvalidProbability); + } + <span class="prelude-val">Ok</span>(Bernoulli { + p_int: (p * SCALE) <span class="kw">as </span>u64, + }) + } + + <span class="doccomment">/// Construct a new `Bernoulli` with the probability of success of + /// `numerator`-in-`denominator`. I.e. `new_ratio(2, 3)` will return + /// a `Bernoulli` with a 2-in-3 chance, or about 67%, of returning `true`. + /// + /// return `true`. If `numerator == 0` it will always return `false`. + /// For `numerator > denominator` and `denominator == 0`, this returns an + /// error. Otherwise, for `numerator == denominator`, samples are always + /// true; for `numerator == 0` samples are always false. + </span><span class="attribute">#[inline] + </span><span class="kw">pub fn </span>from_ratio(numerator: u32, denominator: u32) -> <span class="prelude-ty">Result</span><Bernoulli, BernoulliError> { + <span class="kw">if </span>numerator > denominator || denominator == <span class="number">0 </span>{ + <span class="kw">return </span><span class="prelude-val">Err</span>(BernoulliError::InvalidProbability); + } + <span class="kw">if </span>numerator == denominator { + <span class="kw">return </span><span class="prelude-val">Ok</span>(Bernoulli { p_int: ALWAYS_TRUE }); + } + <span class="kw">let </span>p_int = ((f64::from(numerator) / f64::from(denominator)) * SCALE) <span class="kw">as </span>u64; + <span class="prelude-val">Ok</span>(Bernoulli { p_int }) + } +} + +<span class="kw">impl </span>Distribution<bool> <span class="kw">for </span>Bernoulli { + <span class="attribute">#[inline] + </span><span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> bool { + <span class="comment">// Make sure to always return true for p = 1.0. + </span><span class="kw">if </span><span class="self">self</span>.p_int == ALWAYS_TRUE { + <span class="kw">return </span><span class="bool-val">true</span>; + } + <span class="kw">let </span>v: u64 = rng.gen(); + v < <span class="self">self</span>.p_int + } +} + +<span class="attribute">#[cfg(test)] +</span><span class="kw">mod </span>test { + <span class="kw">use </span><span class="kw">super</span>::Bernoulli; + <span class="kw">use </span><span class="kw">crate</span>::distributions::Distribution; + <span class="kw">use </span><span class="kw">crate</span>::Rng; + + <span class="attribute">#[test] + #[cfg(feature=<span class="string">"serde1"</span>)] + </span><span class="kw">fn </span>test_serializing_deserializing_bernoulli() { + <span class="kw">let </span>coin_flip = Bernoulli::new(<span class="number">0.5</span>).unwrap(); + <span class="kw">let </span>de_coin_flip : Bernoulli = bincode::deserialize(<span class="kw-2">&</span>bincode::serialize(<span class="kw-2">&</span>coin_flip).unwrap()).unwrap(); + + <span class="macro">assert_eq!</span>(coin_flip.p_int, de_coin_flip.p_int); + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_trivial() { + <span class="comment">// We prefer to be explicit here. + </span><span class="attribute">#![allow(clippy::bool_assert_comparison)] + + </span><span class="kw">let </span><span class="kw-2">mut </span>r = <span class="kw">crate</span>::test::rng(<span class="number">1</span>); + <span class="kw">let </span>always_false = Bernoulli::new(<span class="number">0.0</span>).unwrap(); + <span class="kw">let </span>always_true = Bernoulli::new(<span class="number">1.0</span>).unwrap(); + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">5 </span>{ + <span class="macro">assert_eq!</span>(r.sample::<bool, <span class="kw">_</span>>(<span class="kw-2">&</span>always_false), <span class="bool-val">false</span>); + <span class="macro">assert_eq!</span>(r.sample::<bool, <span class="kw">_</span>>(<span class="kw-2">&</span>always_true), <span class="bool-val">true</span>); + <span class="macro">assert_eq!</span>(Distribution::<bool>::sample(<span class="kw-2">&</span>always_false, <span class="kw-2">&mut </span>r), <span class="bool-val">false</span>); + <span class="macro">assert_eq!</span>(Distribution::<bool>::sample(<span class="kw-2">&</span>always_true, <span class="kw-2">&mut </span>r), <span class="bool-val">true</span>); + } + } + + <span class="attribute">#[test] + #[cfg_attr(miri, ignore)] </span><span class="comment">// Miri is too slow + </span><span class="kw">fn </span>test_average() { + <span class="kw">const </span>P: f64 = <span class="number">0.3</span>; + <span class="kw">const </span>NUM: u32 = <span class="number">3</span>; + <span class="kw">const </span>DENOM: u32 = <span class="number">10</span>; + <span class="kw">let </span>d1 = Bernoulli::new(P).unwrap(); + <span class="kw">let </span>d2 = Bernoulli::from_ratio(NUM, DENOM).unwrap(); + <span class="kw">const </span>N: u32 = <span class="number">100_000</span>; + + <span class="kw">let </span><span class="kw-2">mut </span>sum1: u32 = <span class="number">0</span>; + <span class="kw">let </span><span class="kw-2">mut </span>sum2: u32 = <span class="number">0</span>; + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">2</span>); + <span class="kw">for _ in </span><span class="number">0</span>..N { + <span class="kw">if </span>d1.sample(<span class="kw-2">&mut </span>rng) { + sum1 += <span class="number">1</span>; + } + <span class="kw">if </span>d2.sample(<span class="kw-2">&mut </span>rng) { + sum2 += <span class="number">1</span>; + } + } + <span class="kw">let </span>avg1 = (sum1 <span class="kw">as </span>f64) / (N <span class="kw">as </span>f64); + <span class="macro">assert!</span>((avg1 - P).abs() < <span class="number">5e-3</span>); + + <span class="kw">let </span>avg2 = (sum2 <span class="kw">as </span>f64) / (N <span class="kw">as </span>f64); + <span class="macro">assert!</span>((avg2 - (NUM <span class="kw">as </span>f64) / (DENOM <span class="kw">as </span>f64)).abs() < <span class="number">5e-3</span>); + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>value_stability() { + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">3</span>); + <span class="kw">let </span>distr = Bernoulli::new(<span class="number">0.4532</span>).unwrap(); + <span class="kw">let </span><span class="kw-2">mut </span>buf = [<span class="bool-val">false</span>; <span class="number">10</span>]; + <span class="kw">for </span>x <span class="kw">in </span><span class="kw-2">&mut </span>buf { + <span class="kw-2">*</span>x = rng.sample(<span class="kw-2">&</span>distr); + } + <span class="macro">assert_eq!</span>(buf, [ + <span class="bool-val">true</span>, <span class="bool-val">false</span>, <span class="bool-val">false</span>, <span class="bool-val">true</span>, <span class="bool-val">false</span>, <span class="bool-val">false</span>, <span class="bool-val">true</span>, <span class="bool-val">true</span>, <span class="bool-val">true</span>, <span class="bool-val">true + </span>]); + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>bernoulli_distributions_can_be_compared() { + <span class="macro">assert_eq!</span>(Bernoulli::new(<span class="number">1.0</span>), Bernoulli::new(<span class="number">1.0</span>)); + } +} +</code></pre></div> +</section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="rand" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0 (69f9c33d7 2022-12-12) (Arch Linux rust 1:1.66.0-1)" ></div></body></html>
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href="../../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../../wheel.svg"></a></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> +<span id="2">2</span> +<span id="3">3</span> +<span id="4">4</span> +<span id="5">5</span> +<span id="6">6</span> +<span id="7">7</span> +<span id="8">8</span> +<span id="9">9</span> +<span id="10">10</span> +<span id="11">11</span> +<span id="12">12</span> +<span id="13">13</span> +<span id="14">14</span> +<span id="15">15</span> +<span id="16">16</span> +<span id="17">17</span> +<span id="18">18</span> +<span id="19">19</span> +<span id="20">20</span> +<span id="21">21</span> +<span id="22">22</span> +<span id="23">23</span> +<span id="24">24</span> +<span id="25">25</span> +<span id="26">26</span> +<span id="27">27</span> +<span id="28">28</span> +<span id="29">29</span> +<span id="30">30</span> +<span id="31">31</span> 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+<span id="259">259</span> +<span id="260">260</span> +<span id="261">261</span> +<span id="262">262</span> +<span id="263">263</span> +<span id="264">264</span> +<span id="265">265</span> +<span id="266">266</span> +<span id="267">267</span> +<span id="268">268</span> +<span id="269">269</span> +<span id="270">270</span> +<span id="271">271</span> +<span id="272">272</span> +</pre><pre class="rust"><code><span class="comment">// Copyright 2018 Developers of the Rand project. +// Copyright 2013-2017 The Rust Project Developers. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +</span><span class="doccomment">//! Distribution trait and associates + +</span><span class="kw">use </span><span class="kw">crate</span>::Rng; +<span class="kw">use </span>core::iter; +<span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] +</span><span class="kw">use </span>alloc::string::String; + +<span class="doccomment">/// Types (distributions) that can be used to create a random instance of `T`. +/// +/// It is possible to sample from a distribution through both the +/// `Distribution` and [`Rng`] traits, via `distr.sample(&mut rng)` and +/// `rng.sample(distr)`. They also both offer the [`sample_iter`] method, which +/// produces an iterator that samples from the distribution. +/// +/// All implementations are expected to be immutable; this has the significant +/// advantage of not needing to consider thread safety, and for most +/// distributions efficient state-less sampling algorithms are available. +/// +/// Implementations are typically expected to be portable with reproducible +/// results when used with a PRNG with fixed seed; see the +/// [portability chapter](https://rust-random.github.io/book/portability.html) +/// of The Rust Rand Book. In some cases this does not apply, e.g. the `usize` +/// type requires different sampling on 32-bit and 64-bit machines. +/// +/// [`sample_iter`]: Distribution::sample_iter +</span><span class="kw">pub trait </span>Distribution<T> { + <span class="doccomment">/// Generate a random value of `T`, using `rng` as the source of randomness. + </span><span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> T; + + <span class="doccomment">/// Create an iterator that generates random values of `T`, using `rng` as + /// the source of randomness. + /// + /// Note that this function takes `self` by value. This works since + /// `Distribution<T>` is impl'd for `&D` where `D: Distribution<T>`, + /// however borrowing is not automatic hence `distr.sample_iter(...)` may + /// need to be replaced with `(&distr).sample_iter(...)` to borrow or + /// `(&*distr).sample_iter(...)` to reborrow an existing reference. + /// + /// # Example + /// + /// ``` + /// use rand::thread_rng; + /// use rand::distributions::{Distribution, Alphanumeric, Uniform, Standard}; + /// + /// let mut rng = thread_rng(); + /// + /// // Vec of 16 x f32: + /// let v: Vec<f32> = Standard.sample_iter(&mut rng).take(16).collect(); + /// + /// // String: + /// let s: String = Alphanumeric + /// .sample_iter(&mut rng) + /// .take(7) + /// .map(char::from) + /// .collect(); + /// + /// // Dice-rolling: + /// let die_range = Uniform::new_inclusive(1, 6); + /// let mut roll_die = die_range.sample_iter(&mut rng); + /// while roll_die.next().unwrap() != 6 { + /// println!("Not a 6; rolling again!"); + /// } + /// ``` + </span><span class="kw">fn </span>sample_iter<R>(<span class="self">self</span>, rng: R) -> DistIter<<span class="self">Self</span>, R, T> + <span class="kw">where + </span>R: Rng, + <span class="self">Self</span>: Sized, + { + DistIter { + distr: <span class="self">self</span>, + rng, + phantom: ::core::marker::PhantomData, + } + } + + <span class="doccomment">/// Create a distribution of values of 'S' by mapping the output of `Self` + /// through the closure `F` + /// + /// # Example + /// + /// ``` + /// use rand::thread_rng; + /// use rand::distributions::{Distribution, Uniform}; + /// + /// let mut rng = thread_rng(); + /// + /// let die = Uniform::new_inclusive(1, 6); + /// let even_number = die.map(|num| num % 2 == 0); + /// while !even_number.sample(&mut rng) { + /// println!("Still odd; rolling again!"); + /// } + /// ``` + </span><span class="kw">fn </span>map<F, S>(<span class="self">self</span>, func: F) -> DistMap<<span class="self">Self</span>, F, T, S> + <span class="kw">where + </span>F: Fn(T) -> S, + <span class="self">Self</span>: Sized, + { + DistMap { + distr: <span class="self">self</span>, + func, + phantom: ::core::marker::PhantomData, + } + } +} + +<span class="kw">impl</span><<span class="lifetime">'a</span>, T, D: Distribution<T>> Distribution<T> <span class="kw">for </span><span class="kw-2">&</span><span class="lifetime">'a </span>D { + <span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> T { + (<span class="kw-2">*</span><span class="self">self</span>).sample(rng) + } +} + +<span class="doccomment">/// An iterator that generates random values of `T` with distribution `D`, +/// using `R` as the source of randomness. +/// +/// This `struct` is created by the [`sample_iter`] method on [`Distribution`]. +/// See its documentation for more. +/// +/// [`sample_iter`]: Distribution::sample_iter +</span><span class="attribute">#[derive(Debug)] +</span><span class="kw">pub struct </span>DistIter<D, R, T> { + distr: D, + rng: R, + phantom: ::core::marker::PhantomData<T>, +} + +<span class="kw">impl</span><D, R, T> Iterator <span class="kw">for </span>DistIter<D, R, T> +<span class="kw">where + </span>D: Distribution<T>, + R: Rng, +{ + <span class="kw">type </span>Item = T; + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>next(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><T> { + <span class="comment">// Here, self.rng may be a reference, but we must take &mut anyway. + // Even if sample could take an R: Rng by value, we would need to do this + // since Rng is not copyable and we cannot enforce that this is "reborrowable". + </span><span class="prelude-val">Some</span>(<span class="self">self</span>.distr.sample(<span class="kw-2">&mut </span><span class="self">self</span>.rng)) + } + + <span class="kw">fn </span>size_hint(<span class="kw-2">&</span><span class="self">self</span>) -> (usize, <span class="prelude-ty">Option</span><usize>) { + (usize::max_value(), <span class="prelude-val">None</span>) + } +} + +<span class="kw">impl</span><D, R, T> iter::FusedIterator <span class="kw">for </span>DistIter<D, R, T> +<span class="kw">where + </span>D: Distribution<T>, + R: Rng, +{ +} + +<span class="attribute">#[cfg(features = <span class="string">"nightly"</span>)] +</span><span class="kw">impl</span><D, R, T> iter::TrustedLen <span class="kw">for </span>DistIter<D, R, T> +<span class="kw">where + </span>D: Distribution<T>, + R: Rng, +{ +} + +<span class="doccomment">/// A distribution of values of type `S` derived from the distribution `D` +/// by mapping its output of type `T` through the closure `F`. +/// +/// This `struct` is created by the [`Distribution::map`] method. +/// See its documentation for more. +</span><span class="attribute">#[derive(Debug)] +</span><span class="kw">pub struct </span>DistMap<D, F, T, S> { + distr: D, + func: F, + phantom: ::core::marker::PhantomData<<span class="kw">fn</span>(T) -> S>, +} + +<span class="kw">impl</span><D, F, T, S> Distribution<S> <span class="kw">for </span>DistMap<D, F, T, S> +<span class="kw">where + </span>D: Distribution<T>, + F: Fn(T) -> S, +{ + <span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> S { + (<span class="self">self</span>.func)(<span class="self">self</span>.distr.sample(rng)) + } +} + +<span class="doccomment">/// `String` sampler +/// +/// Sampling a `String` of random characters is not quite the same as collecting +/// a sequence of chars. This trait contains some helpers. +</span><span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] +</span><span class="kw">pub trait </span>DistString { + <span class="doccomment">/// Append `len` random chars to `string` + </span><span class="kw">fn </span>append_string<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R, string: <span class="kw-2">&mut </span>String, len: usize); + + <span class="doccomment">/// Generate a `String` of `len` random chars + </span><span class="attribute">#[inline] + </span><span class="kw">fn </span>sample_string<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R, len: usize) -> String { + <span class="kw">let </span><span class="kw-2">mut </span>s = String::new(); + <span class="self">self</span>.append_string(rng, <span class="kw-2">&mut </span>s, len); + s + } +} + +<span class="attribute">#[cfg(test)] +</span><span class="kw">mod </span>tests { + <span class="kw">use </span><span class="kw">crate</span>::distributions::{Distribution, Uniform}; + <span class="kw">use </span><span class="kw">crate</span>::Rng; + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_distributions_iter() { + <span class="kw">use </span><span class="kw">crate</span>::distributions::Open01; + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">210</span>); + <span class="kw">let </span>distr = Open01; + <span class="kw">let </span><span class="kw-2">mut </span>iter = Distribution::<f32>::sample_iter(distr, <span class="kw-2">&mut </span>rng); + <span class="kw">let </span><span class="kw-2">mut </span>sum: f32 = <span class="number">0.</span>; + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">100 </span>{ + sum += iter.next().unwrap(); + } + <span class="macro">assert!</span>(<span class="number">0. </span>< sum && sum < <span class="number">100.</span>); + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_distributions_map() { + <span class="kw">let </span>dist = Uniform::new_inclusive(<span class="number">0</span>, <span class="number">5</span>).map(|val| val + <span class="number">15</span>); + + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">212</span>); + <span class="kw">let </span>val = dist.sample(<span class="kw-2">&mut </span>rng); + <span class="macro">assert!</span>((<span class="number">15</span>..=<span class="number">20</span>).contains(<span class="kw-2">&</span>val)); + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_make_an_iter() { + <span class="kw">fn </span>ten_dice_rolls_other_than_five<R: Rng>( + rng: <span class="kw-2">&mut </span>R, + ) -> <span class="kw">impl </span>Iterator<Item = i32> + <span class="lifetime">'_ </span>{ + Uniform::new_inclusive(<span class="number">1</span>, <span class="number">6</span>) + .sample_iter(rng) + .filter(|x| <span class="kw-2">*</span>x != <span class="number">5</span>) + .take(<span class="number">10</span>) + } + + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">211</span>); + <span class="kw">let </span><span class="kw-2">mut </span>count = <span class="number">0</span>; + <span class="kw">for </span>val <span class="kw">in </span>ten_dice_rolls_other_than_five(<span class="kw-2">&mut </span>rng) { + <span class="macro">assert!</span>((<span class="number">1</span>..=<span class="number">6</span>).contains(<span class="kw-2">&</span>val) && val != <span class="number">5</span>); + count += <span class="number">1</span>; + } + <span class="macro">assert_eq!</span>(count, <span class="number">10</span>); + } + + <span class="attribute">#[test] + #[cfg(feature = <span class="string">"alloc"</span>)] + </span><span class="kw">fn </span>test_dist_string() { + <span class="kw">use </span>core::str; + <span class="kw">use </span><span class="kw">crate</span>::distributions::{Alphanumeric, DistString, Standard}; + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">213</span>); + + <span class="kw">let </span>s1 = Alphanumeric.sample_string(<span class="kw-2">&mut </span>rng, <span class="number">20</span>); + <span class="macro">assert_eq!</span>(s1.len(), <span class="number">20</span>); + <span class="macro">assert_eq!</span>(str::from_utf8(s1.as_bytes()), <span class="prelude-val">Ok</span>(s1.as_str())); + + <span class="kw">let </span>s2 = Standard.sample_string(<span class="kw-2">&mut </span>rng, <span class="number">20</span>); + <span class="macro">assert_eq!</span>(s2.chars().count(), <span class="number">20</span>); + <span class="macro">assert_eq!</span>(str::from_utf8(s2.as_bytes()), <span class="prelude-val">Ok</span>(s2.as_str())); + } +} +</code></pre></div> +</section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="rand" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0 (69f9c33d7 2022-12-12) (Arch Linux rust 1:1.66.0-1)" ></div></body></html>
\ No newline at end of file diff --git a/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/float.rs.html b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/float.rs.html new file mode 100644 index 0000000..cba1f5b --- /dev/null +++ b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/float.rs.html @@ -0,0 +1,627 @@ +<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/home/pico/.local/share/cargo/registry/src/github.com-1ecc6299db9ec823/rand-0.8.5/src/distributions/float.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>float.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" 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src="../../../wheel.svg"></a></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> +<span id="2">2</span> +<span id="3">3</span> +<span id="4">4</span> +<span id="5">5</span> +<span id="6">6</span> +<span id="7">7</span> +<span id="8">8</span> +<span id="9">9</span> +<span id="10">10</span> +<span id="11">11</span> +<span id="12">12</span> +<span id="13">13</span> +<span id="14">14</span> +<span id="15">15</span> +<span id="16">16</span> +<span id="17">17</span> +<span id="18">18</span> +<span id="19">19</span> +<span id="20">20</span> +<span id="21">21</span> +<span id="22">22</span> +<span id="23">23</span> +<span id="24">24</span> +<span id="25">25</span> +<span id="26">26</span> +<span id="27">27</span> +<span id="28">28</span> +<span id="29">29</span> +<span id="30">30</span> +<span id="31">31</span> +<span id="32">32</span> +<span id="33">33</span> +<span id="34">34</span> +<span 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+<span id="299">299</span> +<span id="300">300</span> +<span id="301">301</span> +<span id="302">302</span> +<span id="303">303</span> +<span id="304">304</span> +<span id="305">305</span> +<span id="306">306</span> +<span id="307">307</span> +<span id="308">308</span> +<span id="309">309</span> +<span id="310">310</span> +<span id="311">311</span> +<span id="312">312</span> +</pre><pre class="rust"><code><span class="comment">// Copyright 2018 Developers of the Rand project. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +</span><span class="doccomment">//! Basic floating-point number distributions + +</span><span class="kw">use </span><span class="kw">crate</span>::distributions::utils::FloatSIMDUtils; +<span class="kw">use </span><span class="kw">crate</span>::distributions::{Distribution, Standard}; +<span class="kw">use </span><span class="kw">crate</span>::Rng; +<span class="kw">use </span>core::mem; +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] </span><span class="kw">use </span>packed_simd::<span class="kw-2">*</span>; + +<span class="attribute">#[cfg(feature = <span class="string">"serde1"</span>)] +</span><span class="kw">use </span>serde::{Serialize, Deserialize}; + +<span class="doccomment">/// A distribution to sample floating point numbers uniformly in the half-open +/// interval `(0, 1]`, i.e. including 1 but not 0. +/// +/// All values that can be generated are of the form `n * ε/2`. For `f32` +/// the 24 most significant random bits of a `u32` are used and for `f64` the +/// 53 most significant bits of a `u64` are used. The conversion uses the +/// multiplicative method. +/// +/// See also: [`Standard`] which samples from `[0, 1)`, [`Open01`] +/// which samples from `(0, 1)` and [`Uniform`] which samples from arbitrary +/// ranges. +/// +/// # Example +/// ``` +/// use rand::{thread_rng, Rng}; +/// use rand::distributions::OpenClosed01; +/// +/// let val: f32 = thread_rng().sample(OpenClosed01); +/// println!("f32 from (0, 1): {}", val); +/// ``` +/// +/// [`Standard`]: crate::distributions::Standard +/// [`Open01`]: crate::distributions::Open01 +/// [`Uniform`]: crate::distributions::uniform::Uniform +</span><span class="attribute">#[derive(Clone, Copy, Debug)] +#[cfg_attr(feature = <span class="string">"serde1"</span>, derive(Serialize, Deserialize))] +</span><span class="kw">pub struct </span>OpenClosed01; + +<span class="doccomment">/// A distribution to sample floating point numbers uniformly in the open +/// interval `(0, 1)`, i.e. not including either endpoint. +/// +/// All values that can be generated are of the form `n * ε + ε/2`. For `f32` +/// the 23 most significant random bits of an `u32` are used, for `f64` 52 from +/// an `u64`. The conversion uses a transmute-based method. +/// +/// See also: [`Standard`] which samples from `[0, 1)`, [`OpenClosed01`] +/// which samples from `(0, 1]` and [`Uniform`] which samples from arbitrary +/// ranges. +/// +/// # Example +/// ``` +/// use rand::{thread_rng, Rng}; +/// use rand::distributions::Open01; +/// +/// let val: f32 = thread_rng().sample(Open01); +/// println!("f32 from (0, 1): {}", val); +/// ``` +/// +/// [`Standard`]: crate::distributions::Standard +/// [`OpenClosed01`]: crate::distributions::OpenClosed01 +/// [`Uniform`]: crate::distributions::uniform::Uniform +</span><span class="attribute">#[derive(Clone, Copy, Debug)] +#[cfg_attr(feature = <span class="string">"serde1"</span>, derive(Serialize, Deserialize))] +</span><span class="kw">pub struct </span>Open01; + + +<span class="comment">// This trait is needed by both this lib and rand_distr hence is a hidden export +</span><span class="attribute">#[doc(hidden)] +</span><span class="kw">pub trait </span>IntoFloat { + <span class="kw">type </span>F; + + <span class="doccomment">/// Helper method to combine the fraction and a constant exponent into a + /// float. + /// + /// Only the least significant bits of `self` may be set, 23 for `f32` and + /// 52 for `f64`. + /// The resulting value will fall in a range that depends on the exponent. + /// As an example the range with exponent 0 will be + /// [2<sup>0</sup>..2<sup>1</sup>), which is [1..2). + </span><span class="kw">fn </span>into_float_with_exponent(<span class="self">self</span>, exponent: i32) -> <span class="self">Self</span>::F; +} + +<span class="macro">macro_rules! </span>float_impls { + (<span class="macro-nonterminal">$ty</span>:ident, <span class="macro-nonterminal">$uty</span>:ident, <span class="macro-nonterminal">$f_scalar</span>:ident, <span class="macro-nonterminal">$u_scalar</span>:ty, + <span class="macro-nonterminal">$fraction_bits</span>:expr, <span class="macro-nonterminal">$exponent_bias</span>:expr) => { + <span class="kw">impl </span>IntoFloat <span class="kw">for </span><span class="macro-nonterminal">$uty </span>{ + <span class="kw">type </span>F = <span class="macro-nonterminal">$ty</span>; + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>into_float_with_exponent(<span class="self">self</span>, exponent: i32) -> <span class="macro-nonterminal">$ty </span>{ + <span class="comment">// The exponent is encoded using an offset-binary representation + </span><span class="kw">let </span>exponent_bits: <span class="macro-nonterminal">$u_scalar </span>= + ((<span class="macro-nonterminal">$exponent_bias </span>+ exponent) <span class="kw">as </span><span class="macro-nonterminal">$u_scalar</span>) << <span class="macro-nonterminal">$fraction_bits</span>; + <span class="macro-nonterminal">$ty::from_bits</span>(<span class="self">self </span>| exponent_bits) + } + } + + <span class="kw">impl </span>Distribution<<span class="macro-nonterminal">$ty</span>> <span class="kw">for </span>Standard { + <span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="macro-nonterminal">$ty </span>{ + <span class="comment">// Multiply-based method; 24/53 random bits; [0, 1) interval. + // We use the most significant bits because for simple RNGs + // those are usually more random. + </span><span class="kw">let </span>float_size = mem::size_of::<<span class="macro-nonterminal">$f_scalar</span>>() <span class="kw">as </span>u32 * <span class="number">8</span>; + <span class="kw">let </span>precision = <span class="macro-nonterminal">$fraction_bits </span>+ <span class="number">1</span>; + <span class="kw">let </span>scale = <span class="number">1.0 </span>/ ((<span class="number">1 </span><span class="kw">as </span><span class="macro-nonterminal">$u_scalar </span><< precision) <span class="kw">as </span><span class="macro-nonterminal">$f_scalar</span>); + + <span class="kw">let </span>value: <span class="macro-nonterminal">$uty </span>= rng.gen(); + <span class="kw">let </span>value = value >> (float_size - precision); + scale * <span class="macro-nonterminal">$ty::cast_from_int</span>(value) + } + } + + <span class="kw">impl </span>Distribution<<span class="macro-nonterminal">$ty</span>> <span class="kw">for </span>OpenClosed01 { + <span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="macro-nonterminal">$ty </span>{ + <span class="comment">// Multiply-based method; 24/53 random bits; (0, 1] interval. + // We use the most significant bits because for simple RNGs + // those are usually more random. + </span><span class="kw">let </span>float_size = mem::size_of::<<span class="macro-nonterminal">$f_scalar</span>>() <span class="kw">as </span>u32 * <span class="number">8</span>; + <span class="kw">let </span>precision = <span class="macro-nonterminal">$fraction_bits </span>+ <span class="number">1</span>; + <span class="kw">let </span>scale = <span class="number">1.0 </span>/ ((<span class="number">1 </span><span class="kw">as </span><span class="macro-nonterminal">$u_scalar </span><< precision) <span class="kw">as </span><span class="macro-nonterminal">$f_scalar</span>); + + <span class="kw">let </span>value: <span class="macro-nonterminal">$uty </span>= rng.gen(); + <span class="kw">let </span>value = value >> (float_size - precision); + <span class="comment">// Add 1 to shift up; will not overflow because of right-shift: + </span>scale * <span class="macro-nonterminal">$ty::cast_from_int</span>(value + <span class="number">1</span>) + } + } + + <span class="kw">impl </span>Distribution<<span class="macro-nonterminal">$ty</span>> <span class="kw">for </span>Open01 { + <span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="macro-nonterminal">$ty </span>{ + <span class="comment">// Transmute-based method; 23/52 random bits; (0, 1) interval. + // We use the most significant bits because for simple RNGs + // those are usually more random. + </span><span class="kw">use </span>core::<span class="macro-nonterminal">$f_scalar::EPSILON</span>; + <span class="kw">let </span>float_size = mem::size_of::<<span class="macro-nonterminal">$f_scalar</span>>() <span class="kw">as </span>u32 * <span class="number">8</span>; + + <span class="kw">let </span>value: <span class="macro-nonterminal">$uty </span>= rng.gen(); + <span class="kw">let </span>fraction = value >> (float_size - <span class="macro-nonterminal">$fraction_bits</span>); + fraction.into_float_with_exponent(<span class="number">0</span>) - (<span class="number">1.0 </span>- EPSILON / <span class="number">2.0</span>) + } + } + } +} + +<span class="macro">float_impls! </span>{ f32, u32, f32, u32, <span class="number">23</span>, <span class="number">127 </span>} +<span class="macro">float_impls! </span>{ f64, u64, f64, u64, <span class="number">52</span>, <span class="number">1023 </span>} + +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="macro">float_impls! </span>{ f32x2, u32x2, f32, u32, <span class="number">23</span>, <span class="number">127 </span>} +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="macro">float_impls! </span>{ f32x4, u32x4, f32, u32, <span class="number">23</span>, <span class="number">127 </span>} +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="macro">float_impls! </span>{ f32x8, u32x8, f32, u32, <span class="number">23</span>, <span class="number">127 </span>} +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="macro">float_impls! </span>{ f32x16, u32x16, f32, u32, <span class="number">23</span>, <span class="number">127 </span>} + +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="macro">float_impls! </span>{ f64x2, u64x2, f64, u64, <span class="number">52</span>, <span class="number">1023 </span>} +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="macro">float_impls! </span>{ f64x4, u64x4, f64, u64, <span class="number">52</span>, <span class="number">1023 </span>} +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="macro">float_impls! </span>{ f64x8, u64x8, f64, u64, <span class="number">52</span>, <span class="number">1023 </span>} + + +<span class="attribute">#[cfg(test)] +</span><span class="kw">mod </span>tests { + <span class="kw">use super</span>::<span class="kw-2">*</span>; + <span class="kw">use </span><span class="kw">crate</span>::rngs::mock::StepRng; + + <span class="kw">const </span>EPSILON32: f32 = ::core::f32::EPSILON; + <span class="kw">const </span>EPSILON64: f64 = ::core::f64::EPSILON; + + <span class="macro">macro_rules! </span>test_f32 { + (<span class="macro-nonterminal">$fnn</span>:ident, <span class="macro-nonterminal">$ty</span>:ident, <span class="macro-nonterminal">$ZERO</span>:expr, <span class="macro-nonterminal">$EPSILON</span>:expr) => { + <span class="attribute">#[test] + </span><span class="kw">fn </span><span class="macro-nonterminal">$fnn</span>() { + <span class="comment">// Standard + </span><span class="kw">let </span><span class="kw-2">mut </span>zeros = StepRng::new(<span class="number">0</span>, <span class="number">0</span>); + <span class="macro">assert_eq!</span>(zeros.gen::<<span class="macro-nonterminal">$ty</span>>(), <span class="macro-nonterminal">$ZERO</span>); + <span class="kw">let </span><span class="kw-2">mut </span>one = StepRng::new(<span class="number">1 </span><< <span class="number">8 </span>| <span class="number">1 </span><< (<span class="number">8 </span>+ <span class="number">32</span>), <span class="number">0</span>); + <span class="macro">assert_eq!</span>(one.gen::<<span class="macro-nonterminal">$ty</span>>(), <span class="macro-nonterminal">$EPSILON </span>/ <span class="number">2.0</span>); + <span class="kw">let </span><span class="kw-2">mut </span>max = StepRng::new(!<span class="number">0</span>, <span class="number">0</span>); + <span class="macro">assert_eq!</span>(max.gen::<<span class="macro-nonterminal">$ty</span>>(), <span class="number">1.0 </span>- <span class="macro-nonterminal">$EPSILON </span>/ <span class="number">2.0</span>); + + <span class="comment">// OpenClosed01 + </span><span class="kw">let </span><span class="kw-2">mut </span>zeros = StepRng::new(<span class="number">0</span>, <span class="number">0</span>); + <span class="macro">assert_eq!</span>(zeros.sample::<<span class="macro-nonterminal">$ty</span>, <span class="kw">_</span>>(OpenClosed01), <span class="number">0.0 </span>+ <span class="macro-nonterminal">$EPSILON </span>/ <span class="number">2.0</span>); + <span class="kw">let </span><span class="kw-2">mut </span>one = StepRng::new(<span class="number">1 </span><< <span class="number">8 </span>| <span class="number">1 </span><< (<span class="number">8 </span>+ <span class="number">32</span>), <span class="number">0</span>); + <span class="macro">assert_eq!</span>(one.sample::<<span class="macro-nonterminal">$ty</span>, <span class="kw">_</span>>(OpenClosed01), <span class="macro-nonterminal">$EPSILON</span>); + <span class="kw">let </span><span class="kw-2">mut </span>max = StepRng::new(!<span class="number">0</span>, <span class="number">0</span>); + <span class="macro">assert_eq!</span>(max.sample::<<span class="macro-nonterminal">$ty</span>, <span class="kw">_</span>>(OpenClosed01), <span class="macro-nonterminal">$ZERO </span>+ <span class="number">1.0</span>); + + <span class="comment">// Open01 + </span><span class="kw">let </span><span class="kw-2">mut </span>zeros = StepRng::new(<span class="number">0</span>, <span class="number">0</span>); + <span class="macro">assert_eq!</span>(zeros.sample::<<span class="macro-nonterminal">$ty</span>, <span class="kw">_</span>>(Open01), <span class="number">0.0 </span>+ <span class="macro-nonterminal">$EPSILON </span>/ <span class="number">2.0</span>); + <span class="kw">let </span><span class="kw-2">mut </span>one = StepRng::new(<span class="number">1 </span><< <span class="number">9 </span>| <span class="number">1 </span><< (<span class="number">9 </span>+ <span class="number">32</span>), <span class="number">0</span>); + <span class="macro">assert_eq!</span>(one.sample::<<span class="macro-nonterminal">$ty</span>, <span class="kw">_</span>>(Open01), <span class="macro-nonterminal">$EPSILON </span>/ <span class="number">2.0 </span>* <span class="number">3.0</span>); + <span class="kw">let </span><span class="kw-2">mut </span>max = StepRng::new(!<span class="number">0</span>, <span class="number">0</span>); + <span class="macro">assert_eq!</span>(max.sample::<<span class="macro-nonterminal">$ty</span>, <span class="kw">_</span>>(Open01), <span class="number">1.0 </span>- <span class="macro-nonterminal">$EPSILON </span>/ <span class="number">2.0</span>); + } + }; + } + <span class="macro">test_f32! </span>{ f32_edge_cases, f32, <span class="number">0.0</span>, EPSILON32 } + <span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] + </span><span class="macro">test_f32! </span>{ f32x2_edge_cases, f32x2, f32x2::splat(<span class="number">0.0</span>), f32x2::splat(EPSILON32) } + <span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] + </span><span class="macro">test_f32! </span>{ f32x4_edge_cases, f32x4, f32x4::splat(<span class="number">0.0</span>), f32x4::splat(EPSILON32) } + <span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] + </span><span class="macro">test_f32! </span>{ f32x8_edge_cases, f32x8, f32x8::splat(<span class="number">0.0</span>), f32x8::splat(EPSILON32) } + <span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] + </span><span class="macro">test_f32! </span>{ f32x16_edge_cases, f32x16, f32x16::splat(<span class="number">0.0</span>), f32x16::splat(EPSILON32) } + + <span class="macro">macro_rules! </span>test_f64 { + (<span class="macro-nonterminal">$fnn</span>:ident, <span class="macro-nonterminal">$ty</span>:ident, <span class="macro-nonterminal">$ZERO</span>:expr, <span class="macro-nonterminal">$EPSILON</span>:expr) => { + <span class="attribute">#[test] + </span><span class="kw">fn </span><span class="macro-nonterminal">$fnn</span>() { + <span class="comment">// Standard + </span><span class="kw">let </span><span class="kw-2">mut </span>zeros = StepRng::new(<span class="number">0</span>, <span class="number">0</span>); + <span class="macro">assert_eq!</span>(zeros.gen::<<span class="macro-nonterminal">$ty</span>>(), <span class="macro-nonterminal">$ZERO</span>); + <span class="kw">let </span><span class="kw-2">mut </span>one = StepRng::new(<span class="number">1 </span><< <span class="number">11</span>, <span class="number">0</span>); + <span class="macro">assert_eq!</span>(one.gen::<<span class="macro-nonterminal">$ty</span>>(), <span class="macro-nonterminal">$EPSILON </span>/ <span class="number">2.0</span>); + <span class="kw">let </span><span class="kw-2">mut </span>max = StepRng::new(!<span class="number">0</span>, <span class="number">0</span>); + <span class="macro">assert_eq!</span>(max.gen::<<span class="macro-nonterminal">$ty</span>>(), <span class="number">1.0 </span>- <span class="macro-nonterminal">$EPSILON </span>/ <span class="number">2.0</span>); + + <span class="comment">// OpenClosed01 + </span><span class="kw">let </span><span class="kw-2">mut </span>zeros = StepRng::new(<span class="number">0</span>, <span class="number">0</span>); + <span class="macro">assert_eq!</span>(zeros.sample::<<span class="macro-nonterminal">$ty</span>, <span class="kw">_</span>>(OpenClosed01), <span class="number">0.0 </span>+ <span class="macro-nonterminal">$EPSILON </span>/ <span class="number">2.0</span>); + <span class="kw">let </span><span class="kw-2">mut </span>one = StepRng::new(<span class="number">1 </span><< <span class="number">11</span>, <span class="number">0</span>); + <span class="macro">assert_eq!</span>(one.sample::<<span class="macro-nonterminal">$ty</span>, <span class="kw">_</span>>(OpenClosed01), <span class="macro-nonterminal">$EPSILON</span>); + <span class="kw">let </span><span class="kw-2">mut </span>max = StepRng::new(!<span class="number">0</span>, <span class="number">0</span>); + <span class="macro">assert_eq!</span>(max.sample::<<span class="macro-nonterminal">$ty</span>, <span class="kw">_</span>>(OpenClosed01), <span class="macro-nonterminal">$ZERO </span>+ <span class="number">1.0</span>); + + <span class="comment">// Open01 + </span><span class="kw">let </span><span class="kw-2">mut </span>zeros = StepRng::new(<span class="number">0</span>, <span class="number">0</span>); + <span class="macro">assert_eq!</span>(zeros.sample::<<span class="macro-nonterminal">$ty</span>, <span class="kw">_</span>>(Open01), <span class="number">0.0 </span>+ <span class="macro-nonterminal">$EPSILON </span>/ <span class="number">2.0</span>); + <span class="kw">let </span><span class="kw-2">mut </span>one = StepRng::new(<span class="number">1 </span><< <span class="number">12</span>, <span class="number">0</span>); + <span class="macro">assert_eq!</span>(one.sample::<<span class="macro-nonterminal">$ty</span>, <span class="kw">_</span>>(Open01), <span class="macro-nonterminal">$EPSILON </span>/ <span class="number">2.0 </span>* <span class="number">3.0</span>); + <span class="kw">let </span><span class="kw-2">mut </span>max = StepRng::new(!<span class="number">0</span>, <span class="number">0</span>); + <span class="macro">assert_eq!</span>(max.sample::<<span class="macro-nonterminal">$ty</span>, <span class="kw">_</span>>(Open01), <span class="number">1.0 </span>- <span class="macro-nonterminal">$EPSILON </span>/ <span class="number">2.0</span>); + } + }; + } + <span class="macro">test_f64! </span>{ f64_edge_cases, f64, <span class="number">0.0</span>, EPSILON64 } + <span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] + </span><span class="macro">test_f64! </span>{ f64x2_edge_cases, f64x2, f64x2::splat(<span class="number">0.0</span>), f64x2::splat(EPSILON64) } + <span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] + </span><span class="macro">test_f64! </span>{ f64x4_edge_cases, f64x4, f64x4::splat(<span class="number">0.0</span>), f64x4::splat(EPSILON64) } + <span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] + </span><span class="macro">test_f64! </span>{ f64x8_edge_cases, f64x8, f64x8::splat(<span class="number">0.0</span>), f64x8::splat(EPSILON64) } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>value_stability() { + <span class="kw">fn </span>test_samples<T: Copy + core::fmt::Debug + PartialEq, D: Distribution<T>>( + distr: <span class="kw-2">&</span>D, zero: T, expected: <span class="kw-2">&</span>[T], + ) { + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">0x6f44f5646c2a7334</span>); + <span class="kw">let </span><span class="kw-2">mut </span>buf = [zero; <span class="number">3</span>]; + <span class="kw">for </span>x <span class="kw">in </span><span class="kw-2">&mut </span>buf { + <span class="kw-2">*</span>x = rng.sample(<span class="kw-2">&</span>distr); + } + <span class="macro">assert_eq!</span>(<span class="kw-2">&</span>buf, expected); + } + + test_samples(<span class="kw-2">&</span>Standard, <span class="number">0f32</span>, <span class="kw-2">&</span>[<span class="number">0.0035963655</span>, <span class="number">0.7346052</span>, <span class="number">0.09778172</span>]); + test_samples(<span class="kw-2">&</span>Standard, <span class="number">0f64</span>, <span class="kw-2">&</span>[ + <span class="number">0.7346051961657583</span>, + <span class="number">0.20298547462974248</span>, + <span class="number">0.8166436635290655</span>, + ]); + + test_samples(<span class="kw-2">&</span>OpenClosed01, <span class="number">0f32</span>, <span class="kw-2">&</span>[<span class="number">0.003596425</span>, <span class="number">0.73460525</span>, <span class="number">0.09778178</span>]); + test_samples(<span class="kw-2">&</span>OpenClosed01, <span class="number">0f64</span>, <span class="kw-2">&</span>[ + <span class="number">0.7346051961657584</span>, + <span class="number">0.2029854746297426</span>, + <span class="number">0.8166436635290656</span>, + ]); + + test_samples(<span class="kw-2">&</span>Open01, <span class="number">0f32</span>, <span class="kw-2">&</span>[<span class="number">0.0035963655</span>, <span class="number">0.73460525</span>, <span class="number">0.09778172</span>]); + test_samples(<span class="kw-2">&</span>Open01, <span class="number">0f64</span>, <span class="kw-2">&</span>[ + <span class="number">0.7346051961657584</span>, + <span class="number">0.20298547462974248</span>, + <span class="number">0.8166436635290656</span>, + ]); + + <span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] + </span>{ + <span class="comment">// We only test a sub-set of types here. Values are identical to + // non-SIMD types; we assume this pattern continues across all + // SIMD types. + + </span>test_samples(<span class="kw-2">&</span>Standard, f32x2::new(<span class="number">0.0</span>, <span class="number">0.0</span>), <span class="kw-2">&</span>[ + f32x2::new(<span class="number">0.0035963655</span>, <span class="number">0.7346052</span>), + f32x2::new(<span class="number">0.09778172</span>, <span class="number">0.20298547</span>), + f32x2::new(<span class="number">0.34296435</span>, <span class="number">0.81664366</span>), + ]); + + test_samples(<span class="kw-2">&</span>Standard, f64x2::new(<span class="number">0.0</span>, <span class="number">0.0</span>), <span class="kw-2">&</span>[ + f64x2::new(<span class="number">0.7346051961657583</span>, <span class="number">0.20298547462974248</span>), + f64x2::new(<span class="number">0.8166436635290655</span>, <span class="number">0.7423708925400552</span>), + f64x2::new(<span class="number">0.16387782224016323</span>, <span class="number">0.9087068770169618</span>), + ]); + } + } +} +</code></pre></div> +</section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="rand" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0 (69f9c33d7 2022-12-12) (Arch Linux rust 1:1.66.0-1)" ></div></body></html>
\ No newline at end of file diff --git a/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/integer.rs.html b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/integer.rs.html new file mode 100644 index 0000000..0fbac64 --- /dev/null +++ b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/integer.rs.html @@ -0,0 +1,551 @@ +<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/home/pico/.local/share/cargo/registry/src/github.com-1ecc6299db9ec823/rand-0.8.5/src/distributions/integer.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>integer.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" 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src="../../../wheel.svg"></a></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> +<span id="2">2</span> +<span id="3">3</span> +<span id="4">4</span> +<span id="5">5</span> +<span id="6">6</span> +<span id="7">7</span> +<span id="8">8</span> +<span id="9">9</span> +<span id="10">10</span> +<span id="11">11</span> +<span id="12">12</span> +<span id="13">13</span> +<span id="14">14</span> +<span id="15">15</span> +<span id="16">16</span> +<span id="17">17</span> +<span id="18">18</span> +<span id="19">19</span> +<span id="20">20</span> +<span id="21">21</span> +<span id="22">22</span> +<span id="23">23</span> +<span id="24">24</span> +<span id="25">25</span> +<span id="26">26</span> +<span id="27">27</span> +<span id="28">28</span> +<span id="29">29</span> +<span id="30">30</span> +<span id="31">31</span> +<span id="32">32</span> +<span id="33">33</span> +<span id="34">34</span> +<span 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+<span id="262">262</span> +<span id="263">263</span> +<span id="264">264</span> +<span id="265">265</span> +<span id="266">266</span> +<span id="267">267</span> +<span id="268">268</span> +<span id="269">269</span> +<span id="270">270</span> +<span id="271">271</span> +<span id="272">272</span> +<span id="273">273</span> +<span id="274">274</span> +</pre><pre class="rust"><code><span class="comment">// Copyright 2018 Developers of the Rand project. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +</span><span class="doccomment">//! The implementations of the `Standard` distribution for integer types. + +</span><span class="kw">use </span><span class="kw">crate</span>::distributions::{Distribution, Standard}; +<span class="kw">use </span><span class="kw">crate</span>::Rng; +<span class="attribute">#[cfg(all(target_arch = <span class="string">"x86"</span>, feature = <span class="string">"simd_support"</span>))] +</span><span class="kw">use </span>core::arch::x86::{__m128i, __m256i}; +<span class="attribute">#[cfg(all(target_arch = <span class="string">"x86_64"</span>, feature = <span class="string">"simd_support"</span>))] +</span><span class="kw">use </span>core::arch::x86_64::{__m128i, __m256i}; +<span class="kw">use </span>core::num::{NonZeroU16, NonZeroU32, NonZeroU64, NonZeroU8, NonZeroUsize, + NonZeroU128}; +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] </span><span class="kw">use </span>packed_simd::<span class="kw-2">*</span>; + +<span class="kw">impl </span>Distribution<u8> <span class="kw">for </span>Standard { + <span class="attribute">#[inline] + </span><span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> u8 { + rng.next_u32() <span class="kw">as </span>u8 + } +} + +<span class="kw">impl </span>Distribution<u16> <span class="kw">for </span>Standard { + <span class="attribute">#[inline] + </span><span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> u16 { + rng.next_u32() <span class="kw">as </span>u16 + } +} + +<span class="kw">impl </span>Distribution<u32> <span class="kw">for </span>Standard { + <span class="attribute">#[inline] + </span><span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> u32 { + rng.next_u32() + } +} + +<span class="kw">impl </span>Distribution<u64> <span class="kw">for </span>Standard { + <span class="attribute">#[inline] + </span><span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> u64 { + rng.next_u64() + } +} + +<span class="kw">impl </span>Distribution<u128> <span class="kw">for </span>Standard { + <span class="attribute">#[inline] + </span><span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> u128 { + <span class="comment">// Use LE; we explicitly generate one value before the next. + </span><span class="kw">let </span>x = u128::from(rng.next_u64()); + <span class="kw">let </span>y = u128::from(rng.next_u64()); + (y << <span class="number">64</span>) | x + } +} + +<span class="kw">impl </span>Distribution<usize> <span class="kw">for </span>Standard { + <span class="attribute">#[inline] + #[cfg(any(target_pointer_width = <span class="string">"32"</span>, target_pointer_width = <span class="string">"16"</span>))] + </span><span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> usize { + rng.next_u32() <span class="kw">as </span>usize + } + + <span class="attribute">#[inline] + #[cfg(target_pointer_width = <span class="string">"64"</span>)] + </span><span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> usize { + rng.next_u64() <span class="kw">as </span>usize + } +} + +<span class="macro">macro_rules! </span>impl_int_from_uint { + (<span class="macro-nonterminal">$ty</span>:ty, <span class="macro-nonterminal">$uty</span>:ty) => { + <span class="kw">impl </span>Distribution<<span class="macro-nonterminal">$ty</span>> <span class="kw">for </span>Standard { + <span class="attribute">#[inline] + </span><span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="macro-nonterminal">$ty </span>{ + rng.gen::<<span class="macro-nonterminal">$uty</span>>() <span class="kw">as </span><span class="macro-nonterminal">$ty + </span>} + } + }; +} + +<span class="macro">impl_int_from_uint! </span>{ i8, u8 } +<span class="macro">impl_int_from_uint! </span>{ i16, u16 } +<span class="macro">impl_int_from_uint! </span>{ i32, u32 } +<span class="macro">impl_int_from_uint! </span>{ i64, u64 } +<span class="macro">impl_int_from_uint! </span>{ i128, u128 } +<span class="macro">impl_int_from_uint! </span>{ isize, usize } + +<span class="macro">macro_rules! </span>impl_nzint { + (<span class="macro-nonterminal">$ty</span>:ty, <span class="macro-nonterminal">$new</span>:path) => { + <span class="kw">impl </span>Distribution<<span class="macro-nonterminal">$ty</span>> <span class="kw">for </span>Standard { + <span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="macro-nonterminal">$ty </span>{ + <span class="kw">loop </span>{ + <span class="kw">if let </span><span class="prelude-val">Some</span>(nz) = <span class="macro-nonterminal">$new</span>(rng.gen()) { + <span class="kw">break </span>nz; + } + } + } + } + }; +} + +<span class="macro">impl_nzint!</span>(NonZeroU8, NonZeroU8::new); +<span class="macro">impl_nzint!</span>(NonZeroU16, NonZeroU16::new); +<span class="macro">impl_nzint!</span>(NonZeroU32, NonZeroU32::new); +<span class="macro">impl_nzint!</span>(NonZeroU64, NonZeroU64::new); +<span class="macro">impl_nzint!</span>(NonZeroU128, NonZeroU128::new); +<span class="macro">impl_nzint!</span>(NonZeroUsize, NonZeroUsize::new); + +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="macro">macro_rules! </span>simd_impl { + ($((<span class="macro-nonterminal">$intrinsic</span>:ident, <span class="macro-nonterminal">$vec</span>:ty),)+) => {$( + <span class="kw">impl </span>Distribution<<span class="macro-nonterminal">$intrinsic</span>> <span class="kw">for </span>Standard { + <span class="attribute">#[inline] + </span><span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="macro-nonterminal">$intrinsic </span>{ + <span class="macro-nonterminal">$intrinsic::from_bits</span>(rng.gen::<<span class="macro-nonterminal">$vec</span>>()) + } + } + )+}; + + (<span class="macro-nonterminal">$bits</span>:expr,) => {}; + (<span class="macro-nonterminal">$bits</span>:expr, <span class="macro-nonterminal">$ty</span>:ty, $(<span class="macro-nonterminal">$ty_more</span>:ty,)<span class="kw-2">*</span>) => { + <span class="macro">simd_impl!</span>(<span class="macro-nonterminal">$bits</span>, $(<span class="macro-nonterminal">$ty_more</span>,)<span class="kw-2">*</span>); + + <span class="kw">impl </span>Distribution<<span class="macro-nonterminal">$ty</span>> <span class="kw">for </span>Standard { + <span class="attribute">#[inline] + </span><span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="macro-nonterminal">$ty </span>{ + <span class="kw">let </span><span class="kw-2">mut </span>vec: <span class="macro-nonterminal">$ty </span>= Default::default(); + <span class="kw">unsafe </span>{ + <span class="kw">let </span>ptr = <span class="kw-2">&mut </span>vec; + <span class="kw">let </span>b_ptr = <span class="kw-2">&mut *</span>(ptr <span class="kw">as </span><span class="kw-2">*mut </span><span class="macro-nonterminal">$ty </span><span class="kw">as </span><span class="kw-2">*mut </span>[u8; <span class="macro-nonterminal">$bits</span>/<span class="number">8</span>]); + rng.fill_bytes(b_ptr); + } + vec.to_le() + } + } + }; +} + +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="macro">simd_impl!</span>(<span class="number">16</span>, u8x2, i8x2,); +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="macro">simd_impl!</span>(<span class="number">32</span>, u8x4, i8x4, u16x2, i16x2,); +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="macro">simd_impl!</span>(<span class="number">64</span>, u8x8, i8x8, u16x4, i16x4, u32x2, i32x2,); +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="macro">simd_impl!</span>(<span class="number">128</span>, u8x16, i8x16, u16x8, i16x8, u32x4, i32x4, u64x2, i64x2,); +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="macro">simd_impl!</span>(<span class="number">256</span>, u8x32, i8x32, u16x16, i16x16, u32x8, i32x8, u64x4, i64x4,); +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="macro">simd_impl!</span>(<span class="number">512</span>, u8x64, i8x64, u16x32, i16x32, u32x16, i32x16, u64x8, i64x8,); +<span class="attribute">#[cfg(all( + feature = <span class="string">"simd_support"</span>, + any(target_arch = <span class="string">"x86"</span>, target_arch = <span class="string">"x86_64"</span>) +))] +</span><span class="macro">simd_impl!</span>((__m128i, u8x16), (__m256i, u8x32),); + +<span class="attribute">#[cfg(test)] +</span><span class="kw">mod </span>tests { + <span class="kw">use super</span>::<span class="kw-2">*</span>; + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_integers() { + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">806</span>); + + rng.sample::<isize, <span class="kw">_</span>>(Standard); + rng.sample::<i8, <span class="kw">_</span>>(Standard); + rng.sample::<i16, <span class="kw">_</span>>(Standard); + rng.sample::<i32, <span class="kw">_</span>>(Standard); + rng.sample::<i64, <span class="kw">_</span>>(Standard); + rng.sample::<i128, <span class="kw">_</span>>(Standard); + + rng.sample::<usize, <span class="kw">_</span>>(Standard); + rng.sample::<u8, <span class="kw">_</span>>(Standard); + rng.sample::<u16, <span class="kw">_</span>>(Standard); + rng.sample::<u32, <span class="kw">_</span>>(Standard); + rng.sample::<u64, <span class="kw">_</span>>(Standard); + rng.sample::<u128, <span class="kw">_</span>>(Standard); + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>value_stability() { + <span class="kw">fn </span>test_samples<T: Copy + core::fmt::Debug + PartialEq>(zero: T, expected: <span class="kw-2">&</span>[T]) + <span class="kw">where </span>Standard: Distribution<T> { + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">807</span>); + <span class="kw">let </span><span class="kw-2">mut </span>buf = [zero; <span class="number">3</span>]; + <span class="kw">for </span>x <span class="kw">in </span><span class="kw-2">&mut </span>buf { + <span class="kw-2">*</span>x = rng.sample(Standard); + } + <span class="macro">assert_eq!</span>(<span class="kw-2">&</span>buf, expected); + } + + test_samples(<span class="number">0u8</span>, <span class="kw-2">&</span>[<span class="number">9</span>, <span class="number">247</span>, <span class="number">111</span>]); + test_samples(<span class="number">0u16</span>, <span class="kw-2">&</span>[<span class="number">32265</span>, <span class="number">42999</span>, <span class="number">38255</span>]); + test_samples(<span class="number">0u32</span>, <span class="kw-2">&</span>[<span class="number">2220326409</span>, <span class="number">2575017975</span>, <span class="number">2018088303</span>]); + test_samples(<span class="number">0u64</span>, <span class="kw-2">&</span>[ + <span class="number">11059617991457472009</span>, + <span class="number">16096616328739788143</span>, + <span class="number">1487364411147516184</span>, + ]); + test_samples(<span class="number">0u128</span>, <span class="kw-2">&</span>[ + <span class="number">296930161868957086625409848350820761097</span>, + <span class="number">145644820879247630242265036535529306392</span>, + <span class="number">111087889832015897993126088499035356354</span>, + ]); + <span class="attribute">#[cfg(any(target_pointer_width = <span class="string">"32"</span>, target_pointer_width = <span class="string">"16"</span>))] + </span>test_samples(<span class="number">0usize</span>, <span class="kw-2">&</span>[<span class="number">2220326409</span>, <span class="number">2575017975</span>, <span class="number">2018088303</span>]); + <span class="attribute">#[cfg(target_pointer_width = <span class="string">"64"</span>)] + </span>test_samples(<span class="number">0usize</span>, <span class="kw-2">&</span>[ + <span class="number">11059617991457472009</span>, + <span class="number">16096616328739788143</span>, + <span class="number">1487364411147516184</span>, + ]); + + test_samples(<span class="number">0i8</span>, <span class="kw-2">&</span>[<span class="number">9</span>, -<span class="number">9</span>, <span class="number">111</span>]); + <span class="comment">// Skip further i* types: they are simple reinterpretation of u* samples + + </span><span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] + </span>{ + <span class="comment">// We only test a sub-set of types here and make assumptions about the rest. + + </span>test_samples(u8x2::default(), <span class="kw-2">&</span>[ + u8x2::new(<span class="number">9</span>, <span class="number">126</span>), + u8x2::new(<span class="number">247</span>, <span class="number">167</span>), + u8x2::new(<span class="number">111</span>, <span class="number">149</span>), + ]); + test_samples(u8x4::default(), <span class="kw-2">&</span>[ + u8x4::new(<span class="number">9</span>, <span class="number">126</span>, <span class="number">87</span>, <span class="number">132</span>), + u8x4::new(<span class="number">247</span>, <span class="number">167</span>, <span class="number">123</span>, <span class="number">153</span>), + u8x4::new(<span class="number">111</span>, <span class="number">149</span>, <span class="number">73</span>, <span class="number">120</span>), + ]); + test_samples(u8x8::default(), <span class="kw-2">&</span>[ + u8x8::new(<span class="number">9</span>, <span class="number">126</span>, <span class="number">87</span>, <span class="number">132</span>, <span class="number">247</span>, <span class="number">167</span>, <span class="number">123</span>, <span class="number">153</span>), + u8x8::new(<span class="number">111</span>, <span class="number">149</span>, <span class="number">73</span>, <span class="number">120</span>, <span class="number">68</span>, <span class="number">171</span>, <span class="number">98</span>, <span class="number">223</span>), + u8x8::new(<span class="number">24</span>, <span class="number">121</span>, <span class="number">1</span>, <span class="number">50</span>, <span class="number">13</span>, <span class="number">46</span>, <span class="number">164</span>, <span class="number">20</span>), + ]); + + test_samples(i64x8::default(), <span class="kw-2">&</span>[ + i64x8::new( + -<span class="number">7387126082252079607</span>, + -<span class="number">2350127744969763473</span>, + <span class="number">1487364411147516184</span>, + <span class="number">7895421560427121838</span>, + <span class="number">602190064936008898</span>, + <span class="number">6022086574635100741</span>, + -<span class="number">5080089175222015595</span>, + -<span class="number">4066367846667249123</span>, + ), + i64x8::new( + <span class="number">9180885022207963908</span>, + <span class="number">3095981199532211089</span>, + <span class="number">6586075293021332726</span>, + <span class="number">419343203796414657</span>, + <span class="number">3186951873057035255</span>, + <span class="number">5287129228749947252</span>, + <span class="number">444726432079249540</span>, + -<span class="number">1587028029513790706</span>, + ), + i64x8::new( + <span class="number">6075236523189346388</span>, + <span class="number">1351763722368165432</span>, + -<span class="number">6192309979959753740</span>, + -<span class="number">7697775502176768592</span>, + -<span class="number">4482022114172078123</span>, + <span class="number">7522501477800909500</span>, + -<span class="number">1837258847956201231</span>, + -<span class="number">586926753024886735</span>, + ), + ]); + } + } +} +</code></pre></div> +</section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="rand" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0 (69f9c33d7 2022-12-12) (Arch Linux rust 1:1.66.0-1)" ></div></body></html>
\ No newline at end of file diff --git a/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/mod.rs.html b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/mod.rs.html new file mode 100644 index 0000000..8e93c46 --- /dev/null +++ b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/mod.rs.html @@ -0,0 +1,439 @@ +<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/home/pico/.local/share/cargo/registry/src/github.com-1ecc6299db9ec823/rand-0.8.5/src/distributions/mod.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>mod.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" 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src="../../../wheel.svg"></a></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> +<span id="2">2</span> +<span id="3">3</span> +<span id="4">4</span> +<span id="5">5</span> +<span id="6">6</span> +<span id="7">7</span> +<span id="8">8</span> +<span id="9">9</span> +<span id="10">10</span> +<span id="11">11</span> +<span id="12">12</span> +<span id="13">13</span> +<span id="14">14</span> +<span id="15">15</span> +<span id="16">16</span> +<span id="17">17</span> +<span id="18">18</span> +<span id="19">19</span> +<span id="20">20</span> +<span id="21">21</span> +<span id="22">22</span> +<span id="23">23</span> +<span id="24">24</span> +<span id="25">25</span> +<span id="26">26</span> +<span id="27">27</span> +<span id="28">28</span> +<span id="29">29</span> +<span id="30">30</span> +<span id="31">31</span> +<span id="32">32</span> +<span id="33">33</span> +<span id="34">34</span> +<span id="35">35</span> +<span id="36">36</span> +<span id="37">37</span> +<span id="38">38</span> +<span id="39">39</span> +<span id="40">40</span> +<span id="41">41</span> +<span id="42">42</span> +<span id="43">43</span> +<span id="44">44</span> +<span id="45">45</span> +<span id="46">46</span> +<span id="47">47</span> +<span id="48">48</span> +<span id="49">49</span> +<span id="50">50</span> +<span id="51">51</span> +<span id="52">52</span> +<span id="53">53</span> +<span id="54">54</span> +<span id="55">55</span> +<span id="56">56</span> +<span id="57">57</span> +<span id="58">58</span> +<span id="59">59</span> +<span id="60">60</span> +<span id="61">61</span> +<span id="62">62</span> +<span id="63">63</span> +<span id="64">64</span> +<span id="65">65</span> +<span id="66">66</span> +<span id="67">67</span> +<span id="68">68</span> +<span id="69">69</span> +<span id="70">70</span> +<span id="71">71</span> +<span id="72">72</span> +<span id="73">73</span> +<span id="74">74</span> +<span 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+<span id="114">114</span> +<span id="115">115</span> +<span id="116">116</span> +<span id="117">117</span> +<span id="118">118</span> +<span id="119">119</span> +<span id="120">120</span> +<span id="121">121</span> +<span id="122">122</span> +<span id="123">123</span> +<span id="124">124</span> +<span id="125">125</span> +<span id="126">126</span> +<span id="127">127</span> +<span id="128">128</span> +<span id="129">129</span> +<span id="130">130</span> +<span id="131">131</span> +<span id="132">132</span> +<span id="133">133</span> +<span id="134">134</span> +<span id="135">135</span> +<span id="136">136</span> +<span id="137">137</span> +<span id="138">138</span> +<span id="139">139</span> +<span id="140">140</span> +<span id="141">141</span> +<span id="142">142</span> +<span id="143">143</span> +<span id="144">144</span> +<span id="145">145</span> +<span id="146">146</span> +<span id="147">147</span> +<span id="148">148</span> +<span id="149">149</span> +<span id="150">150</span> +<span id="151">151</span> +<span id="152">152</span> +<span id="153">153</span> +<span id="154">154</span> +<span id="155">155</span> +<span id="156">156</span> +<span id="157">157</span> +<span id="158">158</span> +<span id="159">159</span> +<span id="160">160</span> +<span id="161">161</span> +<span id="162">162</span> +<span id="163">163</span> +<span id="164">164</span> +<span id="165">165</span> +<span id="166">166</span> +<span id="167">167</span> +<span id="168">168</span> +<span id="169">169</span> +<span id="170">170</span> +<span id="171">171</span> +<span id="172">172</span> +<span id="173">173</span> +<span id="174">174</span> +<span id="175">175</span> +<span id="176">176</span> +<span id="177">177</span> +<span id="178">178</span> +<span id="179">179</span> +<span id="180">180</span> +<span id="181">181</span> +<span id="182">182</span> +<span id="183">183</span> +<span id="184">184</span> +<span id="185">185</span> +<span id="186">186</span> +<span id="187">187</span> +<span id="188">188</span> +<span id="189">189</span> +<span id="190">190</span> +<span id="191">191</span> +<span id="192">192</span> +<span id="193">193</span> +<span id="194">194</span> +<span id="195">195</span> +<span id="196">196</span> +<span id="197">197</span> +<span id="198">198</span> +<span id="199">199</span> +<span id="200">200</span> +<span id="201">201</span> +<span id="202">202</span> +<span id="203">203</span> +<span id="204">204</span> +<span id="205">205</span> +<span id="206">206</span> +<span id="207">207</span> +<span id="208">208</span> +<span id="209">209</span> +<span id="210">210</span> +<span id="211">211</span> +<span id="212">212</span> +<span id="213">213</span> +<span id="214">214</span> +<span id="215">215</span> +<span id="216">216</span> +<span id="217">217</span> +<span id="218">218</span> +</pre><pre class="rust"><code><span class="comment">// Copyright 2018 Developers of the Rand project. +// Copyright 2013-2017 The Rust Project Developers. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +</span><span class="doccomment">//! Generating random samples from probability distributions +//! +//! This module is the home of the [`Distribution`] trait and several of its +//! implementations. It is the workhorse behind some of the convenient +//! functionality of the [`Rng`] trait, e.g. [`Rng::gen`] and of course +//! [`Rng::sample`]. +//! +//! Abstractly, a [probability distribution] describes the probability of +//! occurrence of each value in its sample space. +//! +//! More concretely, an implementation of `Distribution<T>` for type `X` is an +//! algorithm for choosing values from the sample space (a subset of `T`) +//! according to the distribution `X` represents, using an external source of +//! randomness (an RNG supplied to the `sample` function). +//! +//! A type `X` may implement `Distribution<T>` for multiple types `T`. +//! Any type implementing [`Distribution`] is stateless (i.e. immutable), +//! but it may have internal parameters set at construction time (for example, +//! [`Uniform`] allows specification of its sample space as a range within `T`). +//! +//! +//! # The `Standard` distribution +//! +//! The [`Standard`] distribution is important to mention. This is the +//! distribution used by [`Rng::gen`] and represents the "default" way to +//! produce a random value for many different types, including most primitive +//! types, tuples, arrays, and a few derived types. See the documentation of +//! [`Standard`] for more details. +//! +//! Implementing `Distribution<T>` for [`Standard`] for user types `T` makes it +//! possible to generate type `T` with [`Rng::gen`], and by extension also +//! with the [`random`] function. +//! +//! ## Random characters +//! +//! [`Alphanumeric`] is a simple distribution to sample random letters and +//! numbers of the `char` type; in contrast [`Standard`] may sample any valid +//! `char`. +//! +//! +//! # Uniform numeric ranges +//! +//! The [`Uniform`] distribution is more flexible than [`Standard`], but also +//! more specialised: it supports fewer target types, but allows the sample +//! space to be specified as an arbitrary range within its target type `T`. +//! Both [`Standard`] and [`Uniform`] are in some sense uniform distributions. +//! +//! Values may be sampled from this distribution using [`Rng::sample(Range)`] or +//! by creating a distribution object with [`Uniform::new`], +//! [`Uniform::new_inclusive`] or `From<Range>`. When the range limits are not +//! known at compile time it is typically faster to reuse an existing +//! `Uniform` object than to call [`Rng::sample(Range)`]. +//! +//! User types `T` may also implement `Distribution<T>` for [`Uniform`], +//! although this is less straightforward than for [`Standard`] (see the +//! documentation in the [`uniform`] module). Doing so enables generation of +//! values of type `T` with [`Rng::sample(Range)`]. +//! +//! ## Open and half-open ranges +//! +//! There are surprisingly many ways to uniformly generate random floats. A +//! range between 0 and 1 is standard, but the exact bounds (open vs closed) +//! and accuracy differ. In addition to the [`Standard`] distribution Rand offers +//! [`Open01`] and [`OpenClosed01`]. See "Floating point implementation" section of +//! [`Standard`] documentation for more details. +//! +//! # Non-uniform sampling +//! +//! Sampling a simple true/false outcome with a given probability has a name: +//! the [`Bernoulli`] distribution (this is used by [`Rng::gen_bool`]). +//! +//! For weighted sampling from a sequence of discrete values, use the +//! [`WeightedIndex`] distribution. +//! +//! This crate no longer includes other non-uniform distributions; instead +//! it is recommended that you use either [`rand_distr`] or [`statrs`]. +//! +//! +//! [probability distribution]: https://en.wikipedia.org/wiki/Probability_distribution +//! [`rand_distr`]: https://crates.io/crates/rand_distr +//! [`statrs`]: https://crates.io/crates/statrs + +//! [`random`]: crate::random +//! [`rand_distr`]: https://crates.io/crates/rand_distr +//! [`statrs`]: https://crates.io/crates/statrs + +</span><span class="kw">mod </span>bernoulli; +<span class="kw">mod </span>distribution; +<span class="kw">mod </span>float; +<span class="kw">mod </span>integer; +<span class="kw">mod </span>other; +<span class="kw">mod </span>slice; +<span class="kw">mod </span>utils; +<span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] +</span><span class="kw">mod </span>weighted_index; + +<span class="attribute">#[doc(hidden)] +</span><span class="kw">pub mod </span>hidden_export { + <span class="kw">pub use </span><span class="kw">super</span>::float::IntoFloat; <span class="comment">// used by rand_distr +</span>} +<span class="kw">pub mod </span>uniform; +<span class="attribute">#[deprecated( + since = <span class="string">"0.8.0"</span>, + note = <span class="string">"use rand::distributions::{WeightedIndex, WeightedError} instead" +</span>)] +#[cfg(feature = <span class="string">"alloc"</span>)] +#[cfg_attr(doc_cfg, doc(cfg(feature = <span class="string">"alloc"</span>)))] +</span><span class="kw">pub mod </span>weighted; + +<span class="kw">pub use </span><span class="self">self</span>::bernoulli::{Bernoulli, BernoulliError}; +<span class="kw">pub use </span><span class="self">self</span>::distribution::{Distribution, DistIter, DistMap}; +<span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] +</span><span class="kw">pub use </span><span class="self">self</span>::distribution::DistString; +<span class="kw">pub use </span><span class="self">self</span>::float::{Open01, OpenClosed01}; +<span class="kw">pub use </span><span class="self">self</span>::other::Alphanumeric; +<span class="kw">pub use </span><span class="self">self</span>::slice::Slice; +<span class="attribute">#[doc(inline)] +</span><span class="kw">pub use </span><span class="self">self</span>::uniform::Uniform; +<span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] +</span><span class="kw">pub use </span><span class="self">self</span>::weighted_index::{WeightedError, WeightedIndex}; + +<span class="attribute">#[allow(unused)] +</span><span class="kw">use </span><span class="kw">crate</span>::Rng; + +<span class="doccomment">/// A generic random value distribution, implemented for many primitive types. +/// Usually generates values with a numerically uniform distribution, and with a +/// range appropriate to the type. +/// +/// ## Provided implementations +/// +/// Assuming the provided `Rng` is well-behaved, these implementations +/// generate values with the following ranges and distributions: +/// +/// * Integers (`i32`, `u32`, `isize`, `usize`, etc.): Uniformly distributed +/// over all values of the type. +/// * `char`: Uniformly distributed over all Unicode scalar values, i.e. all +/// code points in the range `0...0x10_FFFF`, except for the range +/// `0xD800...0xDFFF` (the surrogate code points). This includes +/// unassigned/reserved code points. +/// * `bool`: Generates `false` or `true`, each with probability 0.5. +/// * Floating point types (`f32` and `f64`): Uniformly distributed in the +/// half-open range `[0, 1)`. See notes below. +/// * Wrapping integers (`Wrapping<T>`), besides the type identical to their +/// normal integer variants. +/// +/// The `Standard` distribution also supports generation of the following +/// compound types where all component types are supported: +/// +/// * Tuples (up to 12 elements): each element is generated sequentially. +/// * Arrays (up to 32 elements): each element is generated sequentially; +/// see also [`Rng::fill`] which supports arbitrary array length for integer +/// and float types and tends to be faster for `u32` and smaller types. +/// When using `rustc` ≥ 1.51, enable the `min_const_gen` feature to support +/// arrays larger than 32 elements. +/// Note that [`Rng::fill`] and `Standard`'s array support are *not* equivalent: +/// the former is optimised for integer types (using fewer RNG calls for +/// element types smaller than the RNG word size), while the latter supports +/// any element type supported by `Standard`. +/// * `Option<T>` first generates a `bool`, and if true generates and returns +/// `Some(value)` where `value: T`, otherwise returning `None`. +/// +/// ## Custom implementations +/// +/// The [`Standard`] distribution may be implemented for user types as follows: +/// +/// ``` +/// # #![allow(dead_code)] +/// use rand::Rng; +/// use rand::distributions::{Distribution, Standard}; +/// +/// struct MyF32 { +/// x: f32, +/// } +/// +/// impl Distribution<MyF32> for Standard { +/// fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> MyF32 { +/// MyF32 { x: rng.gen() } +/// } +/// } +/// ``` +/// +/// ## Example usage +/// ``` +/// use rand::prelude::*; +/// use rand::distributions::Standard; +/// +/// let val: f32 = StdRng::from_entropy().sample(Standard); +/// println!("f32 from [0, 1): {}", val); +/// ``` +/// +/// # Floating point implementation +/// The floating point implementations for `Standard` generate a random value in +/// the half-open interval `[0, 1)`, i.e. including 0 but not 1. +/// +/// All values that can be generated are of the form `n * ε/2`. For `f32` +/// the 24 most significant random bits of a `u32` are used and for `f64` the +/// 53 most significant bits of a `u64` are used. The conversion uses the +/// multiplicative method: `(rng.gen::<$uty>() >> N) as $ty * (ε/2)`. +/// +/// See also: [`Open01`] which samples from `(0, 1)`, [`OpenClosed01`] which +/// samples from `(0, 1]` and `Rng::gen_range(0..1)` which also samples from +/// `[0, 1)`. Note that `Open01` uses transmute-based methods which yield 1 bit +/// less precision but may perform faster on some architectures (on modern Intel +/// CPUs all methods have approximately equal performance). +/// +/// [`Uniform`]: uniform::Uniform +</span><span class="attribute">#[derive(Clone, Copy, Debug)] +#[cfg_attr(feature = <span class="string">"serde1"</span>, derive(serde::Serialize, serde::Deserialize))] +</span><span class="kw">pub struct </span>Standard; +</code></pre></div> +</section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="rand" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0 (69f9c33d7 2022-12-12) (Arch Linux rust 1:1.66.0-1)" ></div></body></html>
\ No newline at end of file diff --git a/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/other.rs.html b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/other.rs.html new file mode 100644 index 0000000..415f1da --- /dev/null +++ b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/other.rs.html @@ -0,0 +1,733 @@ +<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/home/pico/.local/share/cargo/registry/src/github.com-1ecc6299db9ec823/rand-0.8.5/src/distributions/other.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>other.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" 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src="../../../wheel.svg"></a></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> +<span id="2">2</span> +<span id="3">3</span> +<span id="4">4</span> +<span id="5">5</span> +<span id="6">6</span> +<span id="7">7</span> +<span id="8">8</span> +<span id="9">9</span> +<span id="10">10</span> +<span id="11">11</span> +<span id="12">12</span> +<span id="13">13</span> +<span id="14">14</span> +<span id="15">15</span> +<span id="16">16</span> +<span id="17">17</span> +<span id="18">18</span> +<span id="19">19</span> +<span id="20">20</span> +<span id="21">21</span> +<span id="22">22</span> +<span id="23">23</span> +<span id="24">24</span> +<span id="25">25</span> +<span id="26">26</span> +<span id="27">27</span> +<span id="28">28</span> +<span id="29">29</span> +<span id="30">30</span> +<span id="31">31</span> +<span id="32">32</span> +<span id="33">33</span> +<span id="34">34</span> +<span 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https://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +</span><span class="doccomment">//! The implementations of the `Standard` distribution for other built-in types. + +</span><span class="kw">use </span>core::char; +<span class="kw">use </span>core::num::Wrapping; +<span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] +</span><span class="kw">use </span>alloc::string::String; + +<span class="kw">use </span><span class="kw">crate</span>::distributions::{Distribution, Standard, Uniform}; +<span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] +</span><span class="kw">use </span><span class="kw">crate</span>::distributions::DistString; +<span class="kw">use </span><span class="kw">crate</span>::Rng; + +<span class="attribute">#[cfg(feature = <span class="string">"serde1"</span>)] +</span><span class="kw">use </span>serde::{Serialize, Deserialize}; +<span class="attribute">#[cfg(feature = <span class="string">"min_const_gen"</span>)] +</span><span class="kw">use </span>core::mem::{<span class="self">self</span>, MaybeUninit}; + + +<span class="comment">// ----- Sampling distributions ----- + +</span><span class="doccomment">/// Sample a `u8`, uniformly distributed over ASCII letters and numbers: +/// a-z, A-Z and 0-9. +/// +/// # Example +/// +/// ``` +/// use rand::{Rng, thread_rng}; +/// use rand::distributions::Alphanumeric; +/// +/// let mut rng = thread_rng(); +/// let chars: String = (0..7).map(|_| rng.sample(Alphanumeric) as char).collect(); +/// println!("Random chars: {}", chars); +/// ``` +/// +/// The [`DistString`] trait provides an easier method of generating +/// a random `String`, and offers more efficient allocation: +/// ``` +/// use rand::distributions::{Alphanumeric, DistString}; +/// let string = Alphanumeric.sample_string(&mut rand::thread_rng(), 16); +/// println!("Random string: {}", string); +/// ``` +/// +/// # Passwords +/// +/// Users sometimes ask whether it is safe to use a string of random characters +/// as a password. In principle, all RNGs in Rand implementing `CryptoRng` are +/// suitable as a source of randomness for generating passwords (if they are +/// properly seeded), but it is more conservative to only use randomness +/// directly from the operating system via the `getrandom` crate, or the +/// corresponding bindings of a crypto library. +/// +/// When generating passwords or keys, it is important to consider the threat +/// model and in some cases the memorability of the password. This is out of +/// scope of the Rand project, and therefore we defer to the following +/// references: +/// +/// - [Wikipedia article on Password Strength](https://en.wikipedia.org/wiki/Password_strength) +/// - [Diceware for generating memorable passwords](https://en.wikipedia.org/wiki/Diceware) +</span><span class="attribute">#[derive(Debug, Clone, Copy)] +#[cfg_attr(feature = <span class="string">"serde1"</span>, derive(Serialize, Deserialize))] +</span><span class="kw">pub struct </span>Alphanumeric; + + +<span class="comment">// ----- Implementations of distributions ----- + +</span><span class="kw">impl </span>Distribution<char> <span class="kw">for </span>Standard { + <span class="attribute">#[inline] + </span><span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> char { + <span class="comment">// A valid `char` is either in the interval `[0, 0xD800)` or + // `(0xDFFF, 0x11_0000)`. All `char`s must therefore be in + // `[0, 0x11_0000)` but not in the "gap" `[0xD800, 0xDFFF]` which is + // reserved for surrogates. This is the size of that gap. + </span><span class="kw">const </span>GAP_SIZE: u32 = <span class="number">0xDFFF </span>- <span class="number">0xD800 </span>+ <span class="number">1</span>; + + <span class="comment">// Uniform::new(0, 0x11_0000 - GAP_SIZE) can also be used but it + // seemed slower. + </span><span class="kw">let </span>range = Uniform::new(GAP_SIZE, <span class="number">0x11_0000</span>); + + <span class="kw">let </span><span class="kw-2">mut </span>n = range.sample(rng); + <span class="kw">if </span>n <= <span class="number">0xDFFF </span>{ + n -= GAP_SIZE; + } + <span class="kw">unsafe </span>{ char::from_u32_unchecked(n) } + } +} + +<span class="doccomment">/// Note: the `String` is potentially left with excess capacity; optionally the +/// user may call `string.shrink_to_fit()` afterwards. +</span><span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] +</span><span class="kw">impl </span>DistString <span class="kw">for </span>Standard { + <span class="kw">fn </span>append_string<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R, s: <span class="kw-2">&mut </span>String, len: usize) { + <span class="comment">// A char is encoded with at most four bytes, thus this reservation is + // guaranteed to be sufficient. We do not shrink_to_fit afterwards so + // that repeated usage on the same `String` buffer does not reallocate. + </span>s.reserve(<span class="number">4 </span>* len); + s.extend(Distribution::<char>::sample_iter(<span class="self">self</span>, rng).take(len)); + } +} + +<span class="kw">impl </span>Distribution<u8> <span class="kw">for </span>Alphanumeric { + <span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> u8 { + <span class="kw">const </span>RANGE: u32 = <span class="number">26 </span>+ <span class="number">26 </span>+ <span class="number">10</span>; + <span class="kw">const </span>GEN_ASCII_STR_CHARSET: <span class="kw-2">&</span>[u8] = <span class="string">b"ABCDEFGHIJKLMNOPQRSTUVWXYZ\ + abcdefghijklmnopqrstuvwxyz\ + 0123456789"</span>; + <span class="comment">// We can pick from 62 characters. This is so close to a power of 2, 64, + // that we can do better than `Uniform`. Use a simple bitshift and + // rejection sampling. We do not use a bitmask, because for small RNGs + // the most significant bits are usually of higher quality. + </span><span class="kw">loop </span>{ + <span class="kw">let </span>var = rng.next_u32() >> (<span class="number">32 </span>- <span class="number">6</span>); + <span class="kw">if </span>var < RANGE { + <span class="kw">return </span>GEN_ASCII_STR_CHARSET[var <span class="kw">as </span>usize]; + } + } + } +} + +<span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] +</span><span class="kw">impl </span>DistString <span class="kw">for </span>Alphanumeric { + <span class="kw">fn </span>append_string<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R, string: <span class="kw-2">&mut </span>String, len: usize) { + <span class="kw">unsafe </span>{ + <span class="kw">let </span>v = string.as_mut_vec(); + v.extend(<span class="self">self</span>.sample_iter(rng).take(len)); + } + } +} + +<span class="kw">impl </span>Distribution<bool> <span class="kw">for </span>Standard { + <span class="attribute">#[inline] + </span><span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> bool { + <span class="comment">// We can compare against an arbitrary bit of an u32 to get a bool. + // Because the least significant bits of a lower quality RNG can have + // simple patterns, we compare against the most significant bit. This is + // easiest done using a sign test. + </span>(rng.next_u32() <span class="kw">as </span>i32) < <span class="number">0 + </span>} +} + +<span class="macro">macro_rules! </span>tuple_impl { + <span class="comment">// use variables to indicate the arity of the tuple + </span>($(<span class="macro-nonterminal">$tyvar</span>:ident),* ) => { + <span class="comment">// the trailing commas are for the 1 tuple + </span><span class="kw">impl</span>< $( <span class="macro-nonterminal">$tyvar </span>),* > + Distribution<( $( <span class="macro-nonterminal">$tyvar </span>),* , )> + <span class="kw">for </span>Standard + <span class="kw">where </span>$( Standard: Distribution<<span class="macro-nonterminal">$tyvar</span>> ),* + { + <span class="attribute">#[inline] + </span><span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, _rng: <span class="kw-2">&mut </span>R) -> ( $( <span class="macro-nonterminal">$tyvar </span>),* , ) { + ( + <span class="comment">// use the $tyvar's to get the appropriate number of + // repeats (they're not actually needed) + </span>$( + _rng.gen::<<span class="macro-nonterminal">$tyvar</span>>() + ),* + , + ) + } + } + } +} + +<span class="kw">impl </span>Distribution<()> <span class="kw">for </span>Standard { + <span class="attribute">#[allow(clippy::unused_unit)] + #[inline] + </span><span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, <span class="kw">_</span>: <span class="kw-2">&mut </span>R) -> () { + () + } +} +<span class="macro">tuple_impl! </span>{A} +<span class="macro">tuple_impl! </span>{A, B} +<span class="macro">tuple_impl! </span>{A, B, C} +<span class="macro">tuple_impl! </span>{A, B, C, D} +<span class="macro">tuple_impl! </span>{A, B, C, D, E} +<span class="macro">tuple_impl! </span>{A, B, C, D, E, F} +<span class="macro">tuple_impl! </span>{A, B, C, D, E, F, G} +<span class="macro">tuple_impl! </span>{A, B, C, D, E, F, G, H} +<span class="macro">tuple_impl! </span>{A, B, C, D, E, F, G, H, I} +<span class="macro">tuple_impl! </span>{A, B, C, D, E, F, G, H, I, J} +<span class="macro">tuple_impl! </span>{A, B, C, D, E, F, G, H, I, J, K} +<span class="macro">tuple_impl! </span>{A, B, C, D, E, F, G, H, I, J, K, L} + +<span class="attribute">#[cfg(feature = <span class="string">"min_const_gen"</span>)] +#[cfg_attr(doc_cfg, doc(cfg(feature = <span class="string">"min_const_gen"</span>)))] +</span><span class="kw">impl</span><T, <span class="kw">const </span>N: usize> Distribution<[T; N]> <span class="kw">for </span>Standard +<span class="kw">where </span>Standard: Distribution<T> +{ + <span class="attribute">#[inline] + </span><span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, _rng: <span class="kw-2">&mut </span>R) -> [T; N] { + <span class="kw">let </span><span class="kw-2">mut </span>buff: [MaybeUninit<T>; N] = <span class="kw">unsafe </span>{ MaybeUninit::uninit().assume_init() }; + + <span class="kw">for </span>elem <span class="kw">in </span><span class="kw-2">&mut </span>buff { + <span class="kw-2">*</span>elem = MaybeUninit::new(_rng.gen()); + } + + <span class="kw">unsafe </span>{ mem::transmute_copy::<<span class="kw">_</span>, <span class="kw">_</span>>(<span class="kw-2">&</span>buff) } + } +} + +<span class="attribute">#[cfg(not(feature = <span class="string">"min_const_gen"</span>))] +</span><span class="macro">macro_rules! </span>array_impl { + <span class="comment">// recursive, given at least one type parameter: + </span>{<span class="macro-nonterminal">$n</span>:expr, <span class="macro-nonterminal">$t</span>:ident, $(<span class="macro-nonterminal">$ts</span>:ident,)<span class="kw-2">*</span>} => { + <span class="macro">array_impl!</span>{(<span class="macro-nonterminal">$n </span>- <span class="number">1</span>), $(<span class="macro-nonterminal">$ts</span>,)<span class="kw-2">*</span>} + + <span class="kw">impl</span><T> Distribution<[T; <span class="macro-nonterminal">$n</span>]> <span class="kw">for </span>Standard <span class="kw">where </span>Standard: Distribution<T> { + <span class="attribute">#[inline] + </span><span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, _rng: <span class="kw-2">&mut </span>R) -> [T; <span class="macro-nonterminal">$n</span>] { + [_rng.gen::<<span class="macro-nonterminal">$t</span>>(), $(_rng.gen::<<span class="macro-nonterminal">$ts</span>>()),<span class="kw-2">*</span>] + } + } + }; + <span class="comment">// empty case: + </span>{<span class="macro-nonterminal">$n</span>:expr,} => { + <span class="kw">impl</span><T> Distribution<[T; <span class="macro-nonterminal">$n</span>]> <span class="kw">for </span>Standard { + <span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, _rng: <span class="kw-2">&mut </span>R) -> [T; <span class="macro-nonterminal">$n</span>] { [] } + } + }; +} + +<span class="attribute">#[cfg(not(feature = <span class="string">"min_const_gen"</span>))] +</span><span class="macro">array_impl! </span>{<span class="number">32</span>, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,} + +<span class="kw">impl</span><T> Distribution<<span class="prelude-ty">Option</span><T>> <span class="kw">for </span>Standard +<span class="kw">where </span>Standard: Distribution<T> +{ + <span class="attribute">#[inline] + </span><span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="prelude-ty">Option</span><T> { + <span class="comment">// UFCS is needed here: https://github.com/rust-lang/rust/issues/24066 + </span><span class="kw">if </span>rng.gen::<bool>() { + <span class="prelude-val">Some</span>(rng.gen()) + } <span class="kw">else </span>{ + <span class="prelude-val">None + </span>} + } +} + +<span class="kw">impl</span><T> Distribution<Wrapping<T>> <span class="kw">for </span>Standard +<span class="kw">where </span>Standard: Distribution<T> +{ + <span class="attribute">#[inline] + </span><span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> Wrapping<T> { + Wrapping(rng.gen()) + } +} + + +<span class="attribute">#[cfg(test)] +</span><span class="kw">mod </span>tests { + <span class="kw">use super</span>::<span class="kw-2">*</span>; + <span class="kw">use </span><span class="kw">crate</span>::RngCore; + <span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] </span><span class="kw">use </span>alloc::string::String; + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_misc() { + <span class="kw">let </span>rng: <span class="kw-2">&mut </span><span class="kw">dyn </span>RngCore = <span class="kw-2">&mut </span><span class="kw">crate</span>::test::rng(<span class="number">820</span>); + + rng.sample::<char, <span class="kw">_</span>>(Standard); + rng.sample::<bool, <span class="kw">_</span>>(Standard); + } + + <span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] + #[test] + </span><span class="kw">fn </span>test_chars() { + <span class="kw">use </span>core::iter; + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">805</span>); + + <span class="comment">// Test by generating a relatively large number of chars, so we also + // take the rejection sampling path. + </span><span class="kw">let </span>word: String = iter::repeat(()) + .map(|()| rng.gen::<char>()) + .take(<span class="number">1000</span>) + .collect(); + <span class="macro">assert!</span>(!word.is_empty()); + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_alphanumeric() { + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">806</span>); + + <span class="comment">// Test by generating a relatively large number of chars, so we also + // take the rejection sampling path. + </span><span class="kw">let </span><span class="kw-2">mut </span>incorrect = <span class="bool-val">false</span>; + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">100 </span>{ + <span class="kw">let </span>c: char = rng.sample(Alphanumeric).into(); + incorrect |= !((<span class="string">'0'</span>..=<span class="string">'9'</span>).contains(<span class="kw-2">&</span>c) || + (<span class="string">'A'</span>..=<span class="string">'Z'</span>).contains(<span class="kw-2">&</span>c) || + (<span class="string">'a'</span>..=<span class="string">'z'</span>).contains(<span class="kw-2">&</span>c) ); + } + <span class="macro">assert!</span>(!incorrect); + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>value_stability() { + <span class="kw">fn </span>test_samples<T: Copy + core::fmt::Debug + PartialEq, D: Distribution<T>>( + distr: <span class="kw-2">&</span>D, zero: T, expected: <span class="kw-2">&</span>[T], + ) { + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">807</span>); + <span class="kw">let </span><span class="kw-2">mut </span>buf = [zero; <span class="number">5</span>]; + <span class="kw">for </span>x <span class="kw">in </span><span class="kw-2">&mut </span>buf { + <span class="kw-2">*</span>x = rng.sample(<span class="kw-2">&</span>distr); + } + <span class="macro">assert_eq!</span>(<span class="kw-2">&</span>buf, expected); + } + + test_samples(<span class="kw-2">&</span>Standard, <span class="string">'a'</span>, <span class="kw-2">&</span>[ + <span class="string">'\u{8cdac}'</span>, + <span class="string">'\u{a346a}'</span>, + <span class="string">'\u{80120}'</span>, + <span class="string">'\u{ed692}'</span>, + <span class="string">'\u{35888}'</span>, + ]); + test_samples(<span class="kw-2">&</span>Alphanumeric, <span class="number">0</span>, <span class="kw-2">&</span>[<span class="number">104</span>, <span class="number">109</span>, <span class="number">101</span>, <span class="number">51</span>, <span class="number">77</span>]); + test_samples(<span class="kw-2">&</span>Standard, <span class="bool-val">false</span>, <span class="kw-2">&</span>[<span class="bool-val">true</span>, <span class="bool-val">true</span>, <span class="bool-val">false</span>, <span class="bool-val">true</span>, <span class="bool-val">false</span>]); + test_samples(<span class="kw-2">&</span>Standard, <span class="prelude-val">None </span><span class="kw">as </span><span class="prelude-ty">Option</span><bool>, <span class="kw-2">&</span>[ + <span class="prelude-val">Some</span>(<span class="bool-val">true</span>), + <span class="prelude-val">None</span>, + <span class="prelude-val">Some</span>(<span class="bool-val">false</span>), + <span class="prelude-val">None</span>, + <span class="prelude-val">Some</span>(<span class="bool-val">false</span>), + ]); + test_samples(<span class="kw-2">&</span>Standard, Wrapping(<span class="number">0i32</span>), <span class="kw-2">&</span>[ + Wrapping(-<span class="number">2074640887</span>), + Wrapping(-<span class="number">1719949321</span>), + Wrapping(<span class="number">2018088303</span>), + Wrapping(-<span class="number">547181756</span>), + Wrapping(<span class="number">838957336</span>), + ]); + + <span class="comment">// We test only sub-sets of tuple and array impls + </span>test_samples(<span class="kw-2">&</span>Standard, (), <span class="kw-2">&</span>[(), (), (), (), ()]); + test_samples(<span class="kw-2">&</span>Standard, (<span class="bool-val">false</span>,), <span class="kw-2">&</span>[ + (<span class="bool-val">true</span>,), + (<span class="bool-val">true</span>,), + (<span class="bool-val">false</span>,), + (<span class="bool-val">true</span>,), + (<span class="bool-val">false</span>,), + ]); + test_samples(<span class="kw-2">&</span>Standard, (<span class="bool-val">false</span>, <span class="bool-val">false</span>), <span class="kw-2">&</span>[ + (<span class="bool-val">true</span>, <span class="bool-val">true</span>), + (<span class="bool-val">false</span>, <span class="bool-val">true</span>), + (<span class="bool-val">false</span>, <span class="bool-val">false</span>), + (<span class="bool-val">true</span>, <span class="bool-val">false</span>), + (<span class="bool-val">false</span>, <span class="bool-val">false</span>), + ]); + + test_samples(<span class="kw-2">&</span>Standard, [<span class="number">0u8</span>; <span class="number">0</span>], <span class="kw-2">&</span>[[], [], [], [], []]); + test_samples(<span class="kw-2">&</span>Standard, [<span class="number">0u8</span>; <span class="number">3</span>], <span class="kw-2">&</span>[ + [<span class="number">9</span>, <span class="number">247</span>, <span class="number">111</span>], + [<span class="number">68</span>, <span class="number">24</span>, <span class="number">13</span>], + [<span class="number">174</span>, <span class="number">19</span>, <span class="number">194</span>], + [<span class="number">172</span>, <span class="number">69</span>, <span class="number">213</span>], + [<span class="number">149</span>, <span class="number">207</span>, <span class="number">29</span>], + ]); + } +} +</code></pre></div> +</section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="rand" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0 (69f9c33d7 2022-12-12) (Arch Linux rust 1:1.66.0-1)" ></div></body></html>
\ No newline at end of file diff --git a/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/slice.rs.html b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/slice.rs.html new file mode 100644 index 0000000..2f43484 --- /dev/null +++ b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/slice.rs.html @@ -0,0 +1,237 @@ +<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/home/pico/.local/share/cargo/registry/src/github.com-1ecc6299db9ec823/rand-0.8.5/src/distributions/slice.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>slice.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" 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src="../../../wheel.svg"></a></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> +<span id="2">2</span> +<span id="3">3</span> +<span id="4">4</span> +<span id="5">5</span> +<span id="6">6</span> +<span id="7">7</span> +<span id="8">8</span> +<span id="9">9</span> +<span id="10">10</span> +<span id="11">11</span> +<span id="12">12</span> +<span id="13">13</span> +<span id="14">14</span> +<span id="15">15</span> +<span id="16">16</span> +<span id="17">17</span> +<span id="18">18</span> +<span id="19">19</span> +<span id="20">20</span> +<span id="21">21</span> +<span id="22">22</span> +<span id="23">23</span> +<span id="24">24</span> +<span id="25">25</span> +<span id="26">26</span> +<span id="27">27</span> +<span id="28">28</span> +<span id="29">29</span> +<span id="30">30</span> +<span id="31">31</span> +<span id="32">32</span> +<span id="33">33</span> +<span id="34">34</span> +<span 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+<span id="114">114</span> +<span id="115">115</span> +<span id="116">116</span> +<span id="117">117</span> +</pre><pre class="rust"><code><span class="comment">// Copyright 2021 Developers of the Rand project. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +</span><span class="kw">use </span><span class="kw">crate</span>::distributions::{Distribution, Uniform}; + +<span class="doccomment">/// A distribution to sample items uniformly from a slice. +/// +/// [`Slice::new`] constructs a distribution referencing a slice and uniformly +/// samples references from the items in the slice. It may do extra work up +/// front to make sampling of multiple values faster; if only one sample from +/// the slice is required, [`SliceRandom::choose`] can be more efficient. +/// +/// Steps are taken to avoid bias which might be present in naive +/// implementations; for example `slice[rng.gen() % slice.len()]` samples from +/// the slice, but may be more likely to select numbers in the low range than +/// other values. +/// +/// This distribution samples with replacement; each sample is independent. +/// Sampling without replacement requires state to be retained, and therefore +/// cannot be handled by a distribution; you should instead consider methods +/// on [`SliceRandom`], such as [`SliceRandom::choose_multiple`]. +/// +/// # Example +/// +/// ``` +/// use rand::Rng; +/// use rand::distributions::Slice; +/// +/// let vowels = ['a', 'e', 'i', 'o', 'u']; +/// let vowels_dist = Slice::new(&vowels).unwrap(); +/// let rng = rand::thread_rng(); +/// +/// // build a string of 10 vowels +/// let vowel_string: String = rng +/// .sample_iter(&vowels_dist) +/// .take(10) +/// .collect(); +/// +/// println!("{}", vowel_string); +/// assert_eq!(vowel_string.len(), 10); +/// assert!(vowel_string.chars().all(|c| vowels.contains(&c))); +/// ``` +/// +/// For a single sample, [`SliceRandom::choose`][crate::seq::SliceRandom::choose] +/// may be preferred: +/// +/// ``` +/// use rand::seq::SliceRandom; +/// +/// let vowels = ['a', 'e', 'i', 'o', 'u']; +/// let mut rng = rand::thread_rng(); +/// +/// println!("{}", vowels.choose(&mut rng).unwrap()) +/// ``` +/// +/// [`SliceRandom`]: crate::seq::SliceRandom +/// [`SliceRandom::choose`]: crate::seq::SliceRandom::choose +/// [`SliceRandom::choose_multiple`]: crate::seq::SliceRandom::choose_multiple +</span><span class="attribute">#[derive(Debug, Clone, Copy)] +</span><span class="kw">pub struct </span>Slice<<span class="lifetime">'a</span>, T> { + slice: <span class="kw-2">&</span><span class="lifetime">'a </span>[T], + range: Uniform<usize>, +} + +<span class="kw">impl</span><<span class="lifetime">'a</span>, T> Slice<<span class="lifetime">'a</span>, T> { + <span class="doccomment">/// Create a new `Slice` instance which samples uniformly from the slice. + /// Returns `Err` if the slice is empty. + </span><span class="kw">pub fn </span>new(slice: <span class="kw-2">&</span><span class="lifetime">'a </span>[T]) -> <span class="prelude-ty">Result</span><<span class="self">Self</span>, EmptySlice> { + <span class="kw">match </span>slice.len() { + <span class="number">0 </span>=> <span class="prelude-val">Err</span>(EmptySlice), + len => <span class="prelude-val">Ok</span>(<span class="self">Self </span>{ + slice, + range: Uniform::new(<span class="number">0</span>, len), + }), + } + } +} + +<span class="kw">impl</span><<span class="lifetime">'a</span>, T> Distribution<<span class="kw-2">&</span><span class="lifetime">'a </span>T> <span class="kw">for </span>Slice<<span class="lifetime">'a</span>, T> { + <span class="kw">fn </span>sample<R: <span class="kw">crate</span>::Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="kw-2">&</span><span class="lifetime">'a </span>T { + <span class="kw">let </span>idx = <span class="self">self</span>.range.sample(rng); + + <span class="macro">debug_assert!</span>( + idx < <span class="self">self</span>.slice.len(), + <span class="string">"Uniform::new(0, {}) somehow returned {}"</span>, + <span class="self">self</span>.slice.len(), + idx + ); + + <span class="comment">// Safety: at construction time, it was ensured that the slice was + // non-empty, and that the `Uniform` range produces values in range + // for the slice + </span><span class="kw">unsafe </span>{ <span class="self">self</span>.slice.get_unchecked(idx) } + } +} + +<span class="doccomment">/// Error type indicating that a [`Slice`] distribution was improperly +/// constructed with an empty slice. +</span><span class="attribute">#[derive(Debug, Clone, Copy)] +</span><span class="kw">pub struct </span>EmptySlice; + +<span class="kw">impl </span>core::fmt::Display <span class="kw">for </span>EmptySlice { + <span class="kw">fn </span>fmt(<span class="kw-2">&</span><span class="self">self</span>, f: <span class="kw-2">&mut </span>core::fmt::Formatter<<span class="lifetime">'_</span>>) -> core::fmt::Result { + <span class="macro">write!</span>( + f, + <span class="string">"Tried to create a `distributions::Slice` with an empty slice" + </span>) + } +} + +<span class="attribute">#[cfg(feature = <span class="string">"std"</span>)] +</span><span class="kw">impl </span>std::error::Error <span class="kw">for </span>EmptySlice {} +</code></pre></div> +</section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="rand" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0 (69f9c33d7 2022-12-12) (Arch Linux rust 1:1.66.0-1)" ></div></body></html>
\ No newline at end of file diff --git a/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/uniform.rs.html b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/uniform.rs.html new file mode 100644 index 0000000..72d0ba1 --- /dev/null +++ b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/uniform.rs.html @@ -0,0 +1,3319 @@ +<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/home/pico/.local/share/cargo/registry/src/github.com-1ecc6299db9ec823/rand-0.8.5/src/distributions/uniform.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>uniform.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" 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src="../../../wheel.svg"></a></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> +<span id="2">2</span> +<span id="3">3</span> +<span id="4">4</span> +<span id="5">5</span> +<span id="6">6</span> +<span id="7">7</span> +<span id="8">8</span> +<span id="9">9</span> +<span id="10">10</span> +<span id="11">11</span> +<span id="12">12</span> +<span id="13">13</span> +<span id="14">14</span> +<span id="15">15</span> +<span id="16">16</span> +<span id="17">17</span> +<span id="18">18</span> +<span id="19">19</span> +<span id="20">20</span> +<span id="21">21</span> +<span id="22">22</span> +<span id="23">23</span> +<span id="24">24</span> +<span id="25">25</span> +<span id="26">26</span> +<span id="27">27</span> +<span id="28">28</span> +<span id="29">29</span> +<span id="30">30</span> +<span id="31">31</span> +<span id="32">32</span> +<span id="33">33</span> +<span id="34">34</span> +<span 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+<span id="188">188</span> +<span id="189">189</span> +<span id="190">190</span> +<span id="191">191</span> +<span id="192">192</span> +<span id="193">193</span> +<span id="194">194</span> +<span id="195">195</span> +<span id="196">196</span> +<span id="197">197</span> +<span id="198">198</span> +<span id="199">199</span> +<span id="200">200</span> +<span id="201">201</span> +<span id="202">202</span> +<span id="203">203</span> +<span id="204">204</span> +<span id="205">205</span> +<span id="206">206</span> +<span id="207">207</span> +<span id="208">208</span> +<span id="209">209</span> +<span id="210">210</span> +<span id="211">211</span> +<span id="212">212</span> +<span id="213">213</span> +<span id="214">214</span> +<span id="215">215</span> +<span id="216">216</span> +<span id="217">217</span> +<span id="218">218</span> +<span id="219">219</span> +<span id="220">220</span> +<span id="221">221</span> +<span id="222">222</span> +<span id="223">223</span> +<span id="224">224</span> +<span id="225">225</span> +<span id="226">226</span> +<span id="227">227</span> +<span id="228">228</span> +<span id="229">229</span> +<span id="230">230</span> +<span id="231">231</span> +<span id="232">232</span> +<span id="233">233</span> +<span id="234">234</span> +<span id="235">235</span> +<span id="236">236</span> +<span id="237">237</span> +<span id="238">238</span> +<span id="239">239</span> +<span id="240">240</span> +<span id="241">241</span> +<span id="242">242</span> +<span id="243">243</span> +<span id="244">244</span> +<span id="245">245</span> +<span id="246">246</span> +<span id="247">247</span> +<span id="248">248</span> +<span id="249">249</span> +<span id="250">250</span> +<span id="251">251</span> +<span id="252">252</span> +<span id="253">253</span> +<span id="254">254</span> +<span id="255">255</span> +<span id="256">256</span> +<span id="257">257</span> +<span id="258">258</span> +<span id="259">259</span> +<span id="260">260</span> +<span id="261">261</span> 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id="1647">1647</span> +<span id="1648">1648</span> +<span id="1649">1649</span> +<span id="1650">1650</span> +<span id="1651">1651</span> +<span id="1652">1652</span> +<span id="1653">1653</span> +<span id="1654">1654</span> +<span id="1655">1655</span> +<span id="1656">1656</span> +<span id="1657">1657</span> +<span id="1658">1658</span> +</pre><pre class="rust"><code><span class="comment">// Copyright 2018-2020 Developers of the Rand project. +// Copyright 2017 The Rust Project Developers. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +</span><span class="doccomment">//! A distribution uniformly sampling numbers within a given range. +//! +//! [`Uniform`] is the standard distribution to sample uniformly from a range; +//! e.g. `Uniform::new_inclusive(1, 6)` can sample integers from 1 to 6, like a +//! standard die. [`Rng::gen_range`] supports any type supported by +//! [`Uniform`]. +//! +//! This distribution is provided with support for several primitive types +//! (all integer and floating-point types) as well as [`std::time::Duration`], +//! and supports extension to user-defined types via a type-specific *back-end* +//! implementation. +//! +//! The types [`UniformInt`], [`UniformFloat`] and [`UniformDuration`] are the +//! back-ends supporting sampling from primitive integer and floating-point +//! ranges as well as from [`std::time::Duration`]; these types do not normally +//! need to be used directly (unless implementing a derived back-end). +//! +//! # Example usage +//! +//! ``` +//! use rand::{Rng, thread_rng}; +//! use rand::distributions::Uniform; +//! +//! let mut rng = thread_rng(); +//! let side = Uniform::new(-10.0, 10.0); +//! +//! // sample between 1 and 10 points +//! for _ in 0..rng.gen_range(1..=10) { +//! // sample a point from the square with sides -10 - 10 in two dimensions +//! let (x, y) = (rng.sample(side), rng.sample(side)); +//! println!("Point: {}, {}", x, y); +//! } +//! ``` +//! +//! # Extending `Uniform` to support a custom type +//! +//! To extend [`Uniform`] to support your own types, write a back-end which +//! implements the [`UniformSampler`] trait, then implement the [`SampleUniform`] +//! helper trait to "register" your back-end. See the `MyF32` example below. +//! +//! At a minimum, the back-end needs to store any parameters needed for sampling +//! (e.g. the target range) and implement `new`, `new_inclusive` and `sample`. +//! Those methods should include an assert to check the range is valid (i.e. +//! `low < high`). The example below merely wraps another back-end. +//! +//! The `new`, `new_inclusive` and `sample_single` functions use arguments of +//! type SampleBorrow<X> in order to support passing in values by reference or +//! by value. In the implementation of these functions, you can choose to +//! simply use the reference returned by [`SampleBorrow::borrow`], or you can choose +//! to copy or clone the value, whatever is appropriate for your type. +//! +//! ``` +//! use rand::prelude::*; +//! use rand::distributions::uniform::{Uniform, SampleUniform, +//! UniformSampler, UniformFloat, SampleBorrow}; +//! +//! struct MyF32(f32); +//! +//! #[derive(Clone, Copy, Debug)] +//! struct UniformMyF32(UniformFloat<f32>); +//! +//! impl UniformSampler for UniformMyF32 { +//! type X = MyF32; +//! fn new<B1, B2>(low: B1, high: B2) -> Self +//! where B1: SampleBorrow<Self::X> + Sized, +//! B2: SampleBorrow<Self::X> + Sized +//! { +//! UniformMyF32(UniformFloat::<f32>::new(low.borrow().0, high.borrow().0)) +//! } +//! fn new_inclusive<B1, B2>(low: B1, high: B2) -> Self +//! where B1: SampleBorrow<Self::X> + Sized, +//! B2: SampleBorrow<Self::X> + Sized +//! { +//! UniformMyF32(UniformFloat::<f32>::new_inclusive( +//! low.borrow().0, +//! high.borrow().0, +//! )) +//! } +//! fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> Self::X { +//! MyF32(self.0.sample(rng)) +//! } +//! } +//! +//! impl SampleUniform for MyF32 { +//! type Sampler = UniformMyF32; +//! } +//! +//! let (low, high) = (MyF32(17.0f32), MyF32(22.0f32)); +//! let uniform = Uniform::new(low, high); +//! let x = uniform.sample(&mut thread_rng()); +//! ``` +//! +//! [`SampleUniform`]: crate::distributions::uniform::SampleUniform +//! [`UniformSampler`]: crate::distributions::uniform::UniformSampler +//! [`UniformInt`]: crate::distributions::uniform::UniformInt +//! [`UniformFloat`]: crate::distributions::uniform::UniformFloat +//! [`UniformDuration`]: crate::distributions::uniform::UniformDuration +//! [`SampleBorrow::borrow`]: crate::distributions::uniform::SampleBorrow::borrow + +</span><span class="kw">use </span>core::time::Duration; +<span class="kw">use </span>core::ops::{Range, RangeInclusive}; + +<span class="kw">use </span><span class="kw">crate</span>::distributions::float::IntoFloat; +<span class="kw">use </span><span class="kw">crate</span>::distributions::utils::{BoolAsSIMD, FloatAsSIMD, FloatSIMDUtils, WideningMultiply}; +<span class="kw">use </span><span class="kw">crate</span>::distributions::Distribution; +<span class="kw">use crate</span>::{Rng, RngCore}; + +<span class="attribute">#[cfg(not(feature = <span class="string">"std"</span>))] +#[allow(unused_imports)] </span><span class="comment">// rustc doesn't detect that this is actually used +</span><span class="kw">use </span><span class="kw">crate</span>::distributions::utils::Float; + +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] </span><span class="kw">use </span>packed_simd::<span class="kw-2">*</span>; + +<span class="attribute">#[cfg(feature = <span class="string">"serde1"</span>)] +</span><span class="kw">use </span>serde::{Serialize, Deserialize}; + +<span class="doccomment">/// Sample values uniformly between two bounds. +/// +/// [`Uniform::new`] and [`Uniform::new_inclusive`] construct a uniform +/// distribution sampling from the given range; these functions may do extra +/// work up front to make sampling of multiple values faster. If only one sample +/// from the range is required, [`Rng::gen_range`] can be more efficient. +/// +/// When sampling from a constant range, many calculations can happen at +/// compile-time and all methods should be fast; for floating-point ranges and +/// the full range of integer types this should have comparable performance to +/// the `Standard` distribution. +/// +/// Steps are taken to avoid bias which might be present in naive +/// implementations; for example `rng.gen::<u8>() % 170` samples from the range +/// `[0, 169]` but is twice as likely to select numbers less than 85 than other +/// values. Further, the implementations here give more weight to the high-bits +/// generated by the RNG than the low bits, since with some RNGs the low-bits +/// are of lower quality than the high bits. +/// +/// Implementations must sample in `[low, high)` range for +/// `Uniform::new(low, high)`, i.e., excluding `high`. In particular, care must +/// be taken to ensure that rounding never results values `< low` or `>= high`. +/// +/// # Example +/// +/// ``` +/// use rand::distributions::{Distribution, Uniform}; +/// +/// let between = Uniform::from(10..10000); +/// let mut rng = rand::thread_rng(); +/// let mut sum = 0; +/// for _ in 0..1000 { +/// sum += between.sample(&mut rng); +/// } +/// println!("{}", sum); +/// ``` +/// +/// For a single sample, [`Rng::gen_range`] may be preferred: +/// +/// ``` +/// use rand::Rng; +/// +/// let mut rng = rand::thread_rng(); +/// println!("{}", rng.gen_range(0..10)); +/// ``` +/// +/// [`new`]: Uniform::new +/// [`new_inclusive`]: Uniform::new_inclusive +/// [`Rng::gen_range`]: Rng::gen_range +</span><span class="attribute">#[derive(Clone, Copy, Debug, PartialEq)] +#[cfg_attr(feature = <span class="string">"serde1"</span>, derive(Serialize, Deserialize))] +#[cfg_attr(feature = <span class="string">"serde1"</span>, serde(bound(serialize = <span class="string">"X::Sampler: Serialize"</span>)))] +#[cfg_attr(feature = <span class="string">"serde1"</span>, serde(bound(deserialize = <span class="string">"X::Sampler: Deserialize<'de>"</span>)))] +</span><span class="kw">pub struct </span>Uniform<X: SampleUniform>(X::Sampler); + +<span class="kw">impl</span><X: SampleUniform> Uniform<X> { + <span class="doccomment">/// Create a new `Uniform` instance which samples uniformly from the half + /// open range `[low, high)` (excluding `high`). Panics if `low >= high`. + </span><span class="kw">pub fn </span>new<B1, B2>(low: B1, high: B2) -> Uniform<X> + <span class="kw">where + </span>B1: SampleBorrow<X> + Sized, + B2: SampleBorrow<X> + Sized, + { + Uniform(X::Sampler::new(low, high)) + } + + <span class="doccomment">/// Create a new `Uniform` instance which samples uniformly from the closed + /// range `[low, high]` (inclusive). Panics if `low > high`. + </span><span class="kw">pub fn </span>new_inclusive<B1, B2>(low: B1, high: B2) -> Uniform<X> + <span class="kw">where + </span>B1: SampleBorrow<X> + Sized, + B2: SampleBorrow<X> + Sized, + { + Uniform(X::Sampler::new_inclusive(low, high)) + } +} + +<span class="kw">impl</span><X: SampleUniform> Distribution<X> <span class="kw">for </span>Uniform<X> { + <span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> X { + <span class="self">self</span>.<span class="number">0</span>.sample(rng) + } +} + +<span class="doccomment">/// Helper trait for creating objects using the correct implementation of +/// [`UniformSampler`] for the sampling type. +/// +/// See the [module documentation] on how to implement [`Uniform`] range +/// sampling for a custom type. +/// +/// [module documentation]: crate::distributions::uniform +</span><span class="kw">pub trait </span>SampleUniform: Sized { + <span class="doccomment">/// The `UniformSampler` implementation supporting type `X`. + </span><span class="kw">type </span>Sampler: UniformSampler<X = <span class="self">Self</span>>; +} + +<span class="doccomment">/// Helper trait handling actual uniform sampling. +/// +/// See the [module documentation] on how to implement [`Uniform`] range +/// sampling for a custom type. +/// +/// Implementation of [`sample_single`] is optional, and is only useful when +/// the implementation can be faster than `Self::new(low, high).sample(rng)`. +/// +/// [module documentation]: crate::distributions::uniform +/// [`sample_single`]: UniformSampler::sample_single +</span><span class="kw">pub trait </span>UniformSampler: Sized { + <span class="doccomment">/// The type sampled by this implementation. + </span><span class="kw">type </span>X; + + <span class="doccomment">/// Construct self, with inclusive lower bound and exclusive upper bound + /// `[low, high)`. + /// + /// Usually users should not call this directly but instead use + /// `Uniform::new`, which asserts that `low < high` before calling this. + </span><span class="kw">fn </span>new<B1, B2>(low: B1, high: B2) -> <span class="self">Self + </span><span class="kw">where + </span>B1: SampleBorrow<<span class="self">Self</span>::X> + Sized, + B2: SampleBorrow<<span class="self">Self</span>::X> + Sized; + + <span class="doccomment">/// Construct self, with inclusive bounds `[low, high]`. + /// + /// Usually users should not call this directly but instead use + /// `Uniform::new_inclusive`, which asserts that `low <= high` before + /// calling this. + </span><span class="kw">fn </span>new_inclusive<B1, B2>(low: B1, high: B2) -> <span class="self">Self + </span><span class="kw">where + </span>B1: SampleBorrow<<span class="self">Self</span>::X> + Sized, + B2: SampleBorrow<<span class="self">Self</span>::X> + Sized; + + <span class="doccomment">/// Sample a value. + </span><span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="self">Self</span>::X; + + <span class="doccomment">/// Sample a single value uniformly from a range with inclusive lower bound + /// and exclusive upper bound `[low, high)`. + /// + /// By default this is implemented using + /// `UniformSampler::new(low, high).sample(rng)`. However, for some types + /// more optimal implementations for single usage may be provided via this + /// method (which is the case for integers and floats). + /// Results may not be identical. + /// + /// Note that to use this method in a generic context, the type needs to be + /// retrieved via `SampleUniform::Sampler` as follows: + /// ``` + /// use rand::{thread_rng, distributions::uniform::{SampleUniform, UniformSampler}}; + /// # #[allow(unused)] + /// fn sample_from_range<T: SampleUniform>(lb: T, ub: T) -> T { + /// let mut rng = thread_rng(); + /// <T as SampleUniform>::Sampler::sample_single(lb, ub, &mut rng) + /// } + /// ``` + </span><span class="kw">fn </span>sample_single<R: Rng + <span class="question-mark">?</span>Sized, B1, B2>(low: B1, high: B2, rng: <span class="kw-2">&mut </span>R) -> <span class="self">Self</span>::X + <span class="kw">where + </span>B1: SampleBorrow<<span class="self">Self</span>::X> + Sized, + B2: SampleBorrow<<span class="self">Self</span>::X> + Sized, + { + <span class="kw">let </span>uniform: <span class="self">Self </span>= UniformSampler::new(low, high); + uniform.sample(rng) + } + + <span class="doccomment">/// Sample a single value uniformly from a range with inclusive lower bound + /// and inclusive upper bound `[low, high]`. + /// + /// By default this is implemented using + /// `UniformSampler::new_inclusive(low, high).sample(rng)`. However, for + /// some types more optimal implementations for single usage may be provided + /// via this method. + /// Results may not be identical. + </span><span class="kw">fn </span>sample_single_inclusive<R: Rng + <span class="question-mark">?</span>Sized, B1, B2>(low: B1, high: B2, rng: <span class="kw-2">&mut </span>R) + -> <span class="self">Self</span>::X + <span class="kw">where </span>B1: SampleBorrow<<span class="self">Self</span>::X> + Sized, + B2: SampleBorrow<<span class="self">Self</span>::X> + Sized + { + <span class="kw">let </span>uniform: <span class="self">Self </span>= UniformSampler::new_inclusive(low, high); + uniform.sample(rng) + } +} + +<span class="kw">impl</span><X: SampleUniform> From<Range<X>> <span class="kw">for </span>Uniform<X> { + <span class="kw">fn </span>from(r: ::core::ops::Range<X>) -> Uniform<X> { + Uniform::new(r.start, r.end) + } +} + +<span class="kw">impl</span><X: SampleUniform> From<RangeInclusive<X>> <span class="kw">for </span>Uniform<X> { + <span class="kw">fn </span>from(r: ::core::ops::RangeInclusive<X>) -> Uniform<X> { + Uniform::new_inclusive(r.start(), r.end()) + } +} + + +<span class="doccomment">/// Helper trait similar to [`Borrow`] but implemented +/// only for SampleUniform and references to SampleUniform in +/// order to resolve ambiguity issues. +/// +/// [`Borrow`]: std::borrow::Borrow +</span><span class="kw">pub trait </span>SampleBorrow<Borrowed> { + <span class="doccomment">/// Immutably borrows from an owned value. See [`Borrow::borrow`] + /// + /// [`Borrow::borrow`]: std::borrow::Borrow::borrow + </span><span class="kw">fn </span>borrow(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="kw-2">&</span>Borrowed; +} +<span class="kw">impl</span><Borrowed> SampleBorrow<Borrowed> <span class="kw">for </span>Borrowed +<span class="kw">where </span>Borrowed: SampleUniform +{ + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>borrow(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="kw-2">&</span>Borrowed { + <span class="self">self + </span>} +} +<span class="kw">impl</span><<span class="lifetime">'a</span>, Borrowed> SampleBorrow<Borrowed> <span class="kw">for </span><span class="kw-2">&</span><span class="lifetime">'a </span>Borrowed +<span class="kw">where </span>Borrowed: SampleUniform +{ + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>borrow(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="kw-2">&</span>Borrowed { + <span class="kw-2">*</span><span class="self">self + </span>} +} + +<span class="doccomment">/// Range that supports generating a single sample efficiently. +/// +/// Any type implementing this trait can be used to specify the sampled range +/// for `Rng::gen_range`. +</span><span class="kw">pub trait </span>SampleRange<T> { + <span class="doccomment">/// Generate a sample from the given range. + </span><span class="kw">fn </span>sample_single<R: RngCore + <span class="question-mark">?</span>Sized>(<span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> T; + + <span class="doccomment">/// Check whether the range is empty. + </span><span class="kw">fn </span>is_empty(<span class="kw-2">&</span><span class="self">self</span>) -> bool; +} + +<span class="kw">impl</span><T: SampleUniform + PartialOrd> SampleRange<T> <span class="kw">for </span>Range<T> { + <span class="attribute">#[inline] + </span><span class="kw">fn </span>sample_single<R: RngCore + <span class="question-mark">?</span>Sized>(<span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> T { + T::Sampler::sample_single(<span class="self">self</span>.start, <span class="self">self</span>.end, rng) + } + + <span class="attribute">#[inline] + </span><span class="kw">fn </span>is_empty(<span class="kw-2">&</span><span class="self">self</span>) -> bool { + !(<span class="self">self</span>.start < <span class="self">self</span>.end) + } +} + +<span class="kw">impl</span><T: SampleUniform + PartialOrd> SampleRange<T> <span class="kw">for </span>RangeInclusive<T> { + <span class="attribute">#[inline] + </span><span class="kw">fn </span>sample_single<R: RngCore + <span class="question-mark">?</span>Sized>(<span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> T { + T::Sampler::sample_single_inclusive(<span class="self">self</span>.start(), <span class="self">self</span>.end(), rng) + } + + <span class="attribute">#[inline] + </span><span class="kw">fn </span>is_empty(<span class="kw-2">&</span><span class="self">self</span>) -> bool { + !(<span class="self">self</span>.start() <= <span class="self">self</span>.end()) + } +} + + +<span class="comment">//////////////////////////////////////////////////////////////////////////////// + +// What follows are all back-ends. + + +</span><span class="doccomment">/// The back-end implementing [`UniformSampler`] for integer types. +/// +/// Unless you are implementing [`UniformSampler`] for your own type, this type +/// should not be used directly, use [`Uniform`] instead. +/// +/// # Implementation notes +/// +/// For simplicity, we use the same generic struct `UniformInt<X>` for all +/// integer types `X`. This gives us only one field type, `X`; to store unsigned +/// values of this size, we take use the fact that these conversions are no-ops. +/// +/// For a closed range, the number of possible numbers we should generate is +/// `range = (high - low + 1)`. To avoid bias, we must ensure that the size of +/// our sample space, `zone`, is a multiple of `range`; other values must be +/// rejected (by replacing with a new random sample). +/// +/// As a special case, we use `range = 0` to represent the full range of the +/// result type (i.e. for `new_inclusive($ty::MIN, $ty::MAX)`). +/// +/// The optimum `zone` is the largest product of `range` which fits in our +/// (unsigned) target type. We calculate this by calculating how many numbers we +/// must reject: `reject = (MAX + 1) % range = (MAX - range + 1) % range`. Any (large) +/// product of `range` will suffice, thus in `sample_single` we multiply by a +/// power of 2 via bit-shifting (faster but may cause more rejections). +/// +/// The smallest integer PRNGs generate is `u32`. For 8- and 16-bit outputs we +/// use `u32` for our `zone` and samples (because it's not slower and because +/// it reduces the chance of having to reject a sample). In this case we cannot +/// store `zone` in the target type since it is too large, however we know +/// `ints_to_reject < range <= $unsigned::MAX`. +/// +/// An alternative to using a modulus is widening multiply: After a widening +/// multiply by `range`, the result is in the high word. Then comparing the low +/// word against `zone` makes sure our distribution is uniform. +</span><span class="attribute">#[derive(Clone, Copy, Debug, PartialEq)] +#[cfg_attr(feature = <span class="string">"serde1"</span>, derive(Serialize, Deserialize))] +</span><span class="kw">pub struct </span>UniformInt<X> { + low: X, + range: X, + z: X, <span class="comment">// either ints_to_reject or zone depending on implementation +</span>} + +<span class="macro">macro_rules! </span>uniform_int_impl { + (<span class="macro-nonterminal">$ty</span>:ty, <span class="macro-nonterminal">$unsigned</span>:ident, <span class="macro-nonterminal">$u_large</span>:ident) => { + <span class="kw">impl </span>SampleUniform <span class="kw">for </span><span class="macro-nonterminal">$ty </span>{ + <span class="kw">type </span>Sampler = UniformInt<<span class="macro-nonterminal">$ty</span>>; + } + + <span class="kw">impl </span>UniformSampler <span class="kw">for </span>UniformInt<<span class="macro-nonterminal">$ty</span>> { + <span class="comment">// We play free and fast with unsigned vs signed here + // (when $ty is signed), but that's fine, since the + // contract of this macro is for $ty and $unsigned to be + // "bit-equal", so casting between them is a no-op. + + </span><span class="kw">type </span>X = <span class="macro-nonterminal">$ty</span>; + + <span class="attribute">#[inline] </span><span class="comment">// if the range is constant, this helps LLVM to do the + // calculations at compile-time. + </span><span class="kw">fn </span>new<B1, B2>(low_b: B1, high_b: B2) -> <span class="self">Self + </span><span class="kw">where + </span>B1: SampleBorrow<<span class="self">Self</span>::X> + Sized, + B2: SampleBorrow<<span class="self">Self</span>::X> + Sized, + { + <span class="kw">let </span>low = <span class="kw-2">*</span>low_b.borrow(); + <span class="kw">let </span>high = <span class="kw-2">*</span>high_b.borrow(); + <span class="macro">assert!</span>(low < high, <span class="string">"Uniform::new called with `low >= high`"</span>); + UniformSampler::new_inclusive(low, high - <span class="number">1</span>) + } + + <span class="attribute">#[inline] </span><span class="comment">// if the range is constant, this helps LLVM to do the + // calculations at compile-time. + </span><span class="kw">fn </span>new_inclusive<B1, B2>(low_b: B1, high_b: B2) -> <span class="self">Self + </span><span class="kw">where + </span>B1: SampleBorrow<<span class="self">Self</span>::X> + Sized, + B2: SampleBorrow<<span class="self">Self</span>::X> + Sized, + { + <span class="kw">let </span>low = <span class="kw-2">*</span>low_b.borrow(); + <span class="kw">let </span>high = <span class="kw-2">*</span>high_b.borrow(); + <span class="macro">assert!</span>( + low <= high, + <span class="string">"Uniform::new_inclusive called with `low > high`" + </span>); + <span class="kw">let </span>unsigned_max = ::core::<span class="macro-nonterminal">$u_large::MAX</span>; + + <span class="kw">let </span>range = high.wrapping_sub(low).wrapping_add(<span class="number">1</span>) <span class="kw">as </span><span class="macro-nonterminal">$unsigned</span>; + <span class="kw">let </span>ints_to_reject = <span class="kw">if </span>range > <span class="number">0 </span>{ + <span class="kw">let </span>range = <span class="macro-nonterminal">$u_large::from</span>(range); + (unsigned_max - range + <span class="number">1</span>) % range + } <span class="kw">else </span>{ + <span class="number">0 + </span>}; + + UniformInt { + low, + <span class="comment">// These are really $unsigned values, but store as $ty: + </span>range: range <span class="kw">as </span><span class="macro-nonterminal">$ty</span>, + z: ints_to_reject <span class="kw">as </span><span class="macro-nonterminal">$unsigned </span><span class="kw">as </span><span class="macro-nonterminal">$ty</span>, + } + } + + <span class="attribute">#[inline] + </span><span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="self">Self</span>::X { + <span class="kw">let </span>range = <span class="self">self</span>.range <span class="kw">as </span><span class="macro-nonterminal">$unsigned </span><span class="kw">as </span><span class="macro-nonterminal">$u_large</span>; + <span class="kw">if </span>range > <span class="number">0 </span>{ + <span class="kw">let </span>unsigned_max = ::core::<span class="macro-nonterminal">$u_large::MAX</span>; + <span class="kw">let </span>zone = unsigned_max - (<span class="self">self</span>.z <span class="kw">as </span><span class="macro-nonterminal">$unsigned </span><span class="kw">as </span><span class="macro-nonterminal">$u_large</span>); + <span class="kw">loop </span>{ + <span class="kw">let </span>v: <span class="macro-nonterminal">$u_large </span>= rng.gen(); + <span class="kw">let </span>(hi, lo) = v.wmul(range); + <span class="kw">if </span>lo <= zone { + <span class="kw">return </span><span class="self">self</span>.low.wrapping_add(hi <span class="kw">as </span><span class="macro-nonterminal">$ty</span>); + } + } + } <span class="kw">else </span>{ + <span class="comment">// Sample from the entire integer range. + </span>rng.gen() + } + } + + <span class="attribute">#[inline] + </span><span class="kw">fn </span>sample_single<R: Rng + <span class="question-mark">?</span>Sized, B1, B2>(low_b: B1, high_b: B2, rng: <span class="kw-2">&mut </span>R) -> <span class="self">Self</span>::X + <span class="kw">where + </span>B1: SampleBorrow<<span class="self">Self</span>::X> + Sized, + B2: SampleBorrow<<span class="self">Self</span>::X> + Sized, + { + <span class="kw">let </span>low = <span class="kw-2">*</span>low_b.borrow(); + <span class="kw">let </span>high = <span class="kw-2">*</span>high_b.borrow(); + <span class="macro">assert!</span>(low < high, <span class="string">"UniformSampler::sample_single: low >= high"</span>); + <span class="self">Self</span>::sample_single_inclusive(low, high - <span class="number">1</span>, rng) + } + + <span class="attribute">#[inline] + </span><span class="kw">fn </span>sample_single_inclusive<R: Rng + <span class="question-mark">?</span>Sized, B1, B2>(low_b: B1, high_b: B2, rng: <span class="kw-2">&mut </span>R) -> <span class="self">Self</span>::X + <span class="kw">where + </span>B1: SampleBorrow<<span class="self">Self</span>::X> + Sized, + B2: SampleBorrow<<span class="self">Self</span>::X> + Sized, + { + <span class="kw">let </span>low = <span class="kw-2">*</span>low_b.borrow(); + <span class="kw">let </span>high = <span class="kw-2">*</span>high_b.borrow(); + <span class="macro">assert!</span>(low <= high, <span class="string">"UniformSampler::sample_single_inclusive: low > high"</span>); + <span class="kw">let </span>range = high.wrapping_sub(low).wrapping_add(<span class="number">1</span>) <span class="kw">as </span><span class="macro-nonterminal">$unsigned </span><span class="kw">as </span><span class="macro-nonterminal">$u_large</span>; + <span class="comment">// If the above resulted in wrap-around to 0, the range is $ty::MIN..=$ty::MAX, + // and any integer will do. + </span><span class="kw">if </span>range == <span class="number">0 </span>{ + <span class="kw">return </span>rng.gen(); + } + + <span class="kw">let </span>zone = <span class="kw">if </span>::core::<span class="macro-nonterminal">$unsigned::MAX </span><= ::core::u16::MAX <span class="kw">as </span><span class="macro-nonterminal">$unsigned </span>{ + <span class="comment">// Using a modulus is faster than the approximation for + // i8 and i16. I suppose we trade the cost of one + // modulus for near-perfect branch prediction. + </span><span class="kw">let </span>unsigned_max: <span class="macro-nonterminal">$u_large </span>= ::core::<span class="macro-nonterminal">$u_large::MAX</span>; + <span class="kw">let </span>ints_to_reject = (unsigned_max - range + <span class="number">1</span>) % range; + unsigned_max - ints_to_reject + } <span class="kw">else </span>{ + <span class="comment">// conservative but fast approximation. `- 1` is necessary to allow the + // same comparison without bias. + </span>(range << range.leading_zeros()).wrapping_sub(<span class="number">1</span>) + }; + + <span class="kw">loop </span>{ + <span class="kw">let </span>v: <span class="macro-nonterminal">$u_large </span>= rng.gen(); + <span class="kw">let </span>(hi, lo) = v.wmul(range); + <span class="kw">if </span>lo <= zone { + <span class="kw">return </span>low.wrapping_add(hi <span class="kw">as </span><span class="macro-nonterminal">$ty</span>); + } + } + } + } + }; +} + +<span class="macro">uniform_int_impl! </span>{ i8, u8, u32 } +<span class="macro">uniform_int_impl! </span>{ i16, u16, u32 } +<span class="macro">uniform_int_impl! </span>{ i32, u32, u32 } +<span class="macro">uniform_int_impl! </span>{ i64, u64, u64 } +<span class="macro">uniform_int_impl! </span>{ i128, u128, u128 } +<span class="macro">uniform_int_impl! </span>{ isize, usize, usize } +<span class="macro">uniform_int_impl! </span>{ u8, u8, u32 } +<span class="macro">uniform_int_impl! </span>{ u16, u16, u32 } +<span class="macro">uniform_int_impl! </span>{ u32, u32, u32 } +<span class="macro">uniform_int_impl! </span>{ u64, u64, u64 } +<span class="macro">uniform_int_impl! </span>{ usize, usize, usize } +<span class="macro">uniform_int_impl! </span>{ u128, u128, u128 } + +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="macro">macro_rules! </span>uniform_simd_int_impl { + (<span class="macro-nonterminal">$ty</span>:ident, <span class="macro-nonterminal">$unsigned</span>:ident, <span class="macro-nonterminal">$u_scalar</span>:ident) => { + <span class="comment">// The "pick the largest zone that can fit in an `u32`" optimization + // is less useful here. Multiple lanes complicate things, we don't + // know the PRNG's minimal output size, and casting to a larger vector + // is generally a bad idea for SIMD performance. The user can still + // implement it manually. + + // TODO: look into `Uniform::<u32x4>::new(0u32, 100)` functionality + // perhaps `impl SampleUniform for $u_scalar`? + </span><span class="kw">impl </span>SampleUniform <span class="kw">for </span><span class="macro-nonterminal">$ty </span>{ + <span class="kw">type </span>Sampler = UniformInt<<span class="macro-nonterminal">$ty</span>>; + } + + <span class="kw">impl </span>UniformSampler <span class="kw">for </span>UniformInt<<span class="macro-nonterminal">$ty</span>> { + <span class="kw">type </span>X = <span class="macro-nonterminal">$ty</span>; + + <span class="attribute">#[inline] </span><span class="comment">// if the range is constant, this helps LLVM to do the + // calculations at compile-time. + </span><span class="kw">fn </span>new<B1, B2>(low_b: B1, high_b: B2) -> <span class="self">Self + </span><span class="kw">where </span>B1: SampleBorrow<<span class="self">Self</span>::X> + Sized, + B2: SampleBorrow<<span class="self">Self</span>::X> + Sized + { + <span class="kw">let </span>low = <span class="kw-2">*</span>low_b.borrow(); + <span class="kw">let </span>high = <span class="kw-2">*</span>high_b.borrow(); + <span class="macro">assert!</span>(low.lt(high).all(), <span class="string">"Uniform::new called with `low >= high`"</span>); + UniformSampler::new_inclusive(low, high - <span class="number">1</span>) + } + + <span class="attribute">#[inline] </span><span class="comment">// if the range is constant, this helps LLVM to do the + // calculations at compile-time. + </span><span class="kw">fn </span>new_inclusive<B1, B2>(low_b: B1, high_b: B2) -> <span class="self">Self + </span><span class="kw">where </span>B1: SampleBorrow<<span class="self">Self</span>::X> + Sized, + B2: SampleBorrow<<span class="self">Self</span>::X> + Sized + { + <span class="kw">let </span>low = <span class="kw-2">*</span>low_b.borrow(); + <span class="kw">let </span>high = <span class="kw-2">*</span>high_b.borrow(); + <span class="macro">assert!</span>(low.le(high).all(), + <span class="string">"Uniform::new_inclusive called with `low > high`"</span>); + <span class="kw">let </span>unsigned_max = ::core::<span class="macro-nonterminal">$u_scalar::MAX</span>; + + <span class="comment">// NOTE: these may need to be replaced with explicitly + // wrapping operations if `packed_simd` changes + </span><span class="kw">let </span>range: <span class="macro-nonterminal">$unsigned </span>= ((high - low) + <span class="number">1</span>).cast(); + <span class="comment">// `% 0` will panic at runtime. + </span><span class="kw">let </span>not_full_range = range.gt(<span class="macro-nonterminal">$unsigned::splat</span>(<span class="number">0</span>)); + <span class="comment">// replacing 0 with `unsigned_max` allows a faster `select` + // with bitwise OR + </span><span class="kw">let </span>modulo = not_full_range.select(range, <span class="macro-nonterminal">$unsigned::splat</span>(unsigned_max)); + <span class="comment">// wrapping addition + </span><span class="kw">let </span>ints_to_reject = (unsigned_max - range + <span class="number">1</span>) % modulo; + <span class="comment">// When `range` is 0, `lo` of `v.wmul(range)` will always be + // zero which means only one sample is needed. + </span><span class="kw">let </span>zone = unsigned_max - ints_to_reject; + + UniformInt { + low, + <span class="comment">// These are really $unsigned values, but store as $ty: + </span>range: range.cast(), + z: zone.cast(), + } + } + + <span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="self">Self</span>::X { + <span class="kw">let </span>range: <span class="macro-nonterminal">$unsigned </span>= <span class="self">self</span>.range.cast(); + <span class="kw">let </span>zone: <span class="macro-nonterminal">$unsigned </span>= <span class="self">self</span>.z.cast(); + + <span class="comment">// This might seem very slow, generating a whole new + // SIMD vector for every sample rejection. For most uses + // though, the chance of rejection is small and provides good + // general performance. With multiple lanes, that chance is + // multiplied. To mitigate this, we replace only the lanes of + // the vector which fail, iteratively reducing the chance of + // rejection. The replacement method does however add a little + // overhead. Benchmarking or calculating probabilities might + // reveal contexts where this replacement method is slower. + </span><span class="kw">let </span><span class="kw-2">mut </span>v: <span class="macro-nonterminal">$unsigned </span>= rng.gen(); + <span class="kw">loop </span>{ + <span class="kw">let </span>(hi, lo) = v.wmul(range); + <span class="kw">let </span>mask = lo.le(zone); + <span class="kw">if </span>mask.all() { + <span class="kw">let </span>hi: <span class="macro-nonterminal">$ty </span>= hi.cast(); + <span class="comment">// wrapping addition + </span><span class="kw">let </span>result = <span class="self">self</span>.low + hi; + <span class="comment">// `select` here compiles to a blend operation + // When `range.eq(0).none()` the compare and blend + // operations are avoided. + </span><span class="kw">let </span>v: <span class="macro-nonterminal">$ty </span>= v.cast(); + <span class="kw">return </span>range.gt(<span class="macro-nonterminal">$unsigned::splat</span>(<span class="number">0</span>)).select(result, v); + } + <span class="comment">// Replace only the failing lanes + </span>v = mask.select(v, rng.gen()); + } + } + } + }; + + <span class="comment">// bulk implementation + </span>($((<span class="macro-nonterminal">$unsigned</span>:ident, <span class="macro-nonterminal">$signed</span>:ident),)+ <span class="macro-nonterminal">$u_scalar</span>:ident) => { + $( + <span class="macro">uniform_simd_int_impl!</span>(<span class="macro-nonterminal">$unsigned</span>, <span class="macro-nonterminal">$unsigned</span>, <span class="macro-nonterminal">$u_scalar</span>); + <span class="macro">uniform_simd_int_impl!</span>(<span class="macro-nonterminal">$signed</span>, <span class="macro-nonterminal">$unsigned</span>, <span class="macro-nonterminal">$u_scalar</span>); + )+ + }; +} + +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="macro">uniform_simd_int_impl! </span>{ + (u64x2, i64x2), + (u64x4, i64x4), + (u64x8, i64x8), + u64 +} + +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="macro">uniform_simd_int_impl! </span>{ + (u32x2, i32x2), + (u32x4, i32x4), + (u32x8, i32x8), + (u32x16, i32x16), + u32 +} + +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="macro">uniform_simd_int_impl! </span>{ + (u16x2, i16x2), + (u16x4, i16x4), + (u16x8, i16x8), + (u16x16, i16x16), + (u16x32, i16x32), + u16 +} + +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="macro">uniform_simd_int_impl! </span>{ + (u8x2, i8x2), + (u8x4, i8x4), + (u8x8, i8x8), + (u8x16, i8x16), + (u8x32, i8x32), + (u8x64, i8x64), + u8 +} + +<span class="kw">impl </span>SampleUniform <span class="kw">for </span>char { + <span class="kw">type </span>Sampler = UniformChar; +} + +<span class="doccomment">/// The back-end implementing [`UniformSampler`] for `char`. +/// +/// Unless you are implementing [`UniformSampler`] for your own type, this type +/// should not be used directly, use [`Uniform`] instead. +/// +/// This differs from integer range sampling since the range `0xD800..=0xDFFF` +/// are used for surrogate pairs in UCS and UTF-16, and consequently are not +/// valid Unicode code points. We must therefore avoid sampling values in this +/// range. +</span><span class="attribute">#[derive(Clone, Copy, Debug)] +#[cfg_attr(feature = <span class="string">"serde1"</span>, derive(Serialize, Deserialize))] +</span><span class="kw">pub struct </span>UniformChar { + sampler: UniformInt<u32>, +} + +<span class="doccomment">/// UTF-16 surrogate range start +</span><span class="kw">const </span>CHAR_SURROGATE_START: u32 = <span class="number">0xD800</span>; +<span class="doccomment">/// UTF-16 surrogate range size +</span><span class="kw">const </span>CHAR_SURROGATE_LEN: u32 = <span class="number">0xE000 </span>- CHAR_SURROGATE_START; + +<span class="doccomment">/// Convert `char` to compressed `u32` +</span><span class="kw">fn </span>char_to_comp_u32(c: char) -> u32 { + <span class="kw">match </span>c <span class="kw">as </span>u32 { + c <span class="kw">if </span>c >= CHAR_SURROGATE_START => c - CHAR_SURROGATE_LEN, + c => c, + } +} + +<span class="kw">impl </span>UniformSampler <span class="kw">for </span>UniformChar { + <span class="kw">type </span>X = char; + + <span class="attribute">#[inline] </span><span class="comment">// if the range is constant, this helps LLVM to do the + // calculations at compile-time. + </span><span class="kw">fn </span>new<B1, B2>(low_b: B1, high_b: B2) -> <span class="self">Self + </span><span class="kw">where + </span>B1: SampleBorrow<<span class="self">Self</span>::X> + Sized, + B2: SampleBorrow<<span class="self">Self</span>::X> + Sized, + { + <span class="kw">let </span>low = char_to_comp_u32(<span class="kw-2">*</span>low_b.borrow()); + <span class="kw">let </span>high = char_to_comp_u32(<span class="kw-2">*</span>high_b.borrow()); + <span class="kw">let </span>sampler = UniformInt::<u32>::new(low, high); + UniformChar { sampler } + } + + <span class="attribute">#[inline] </span><span class="comment">// if the range is constant, this helps LLVM to do the + // calculations at compile-time. + </span><span class="kw">fn </span>new_inclusive<B1, B2>(low_b: B1, high_b: B2) -> <span class="self">Self + </span><span class="kw">where + </span>B1: SampleBorrow<<span class="self">Self</span>::X> + Sized, + B2: SampleBorrow<<span class="self">Self</span>::X> + Sized, + { + <span class="kw">let </span>low = char_to_comp_u32(<span class="kw-2">*</span>low_b.borrow()); + <span class="kw">let </span>high = char_to_comp_u32(<span class="kw-2">*</span>high_b.borrow()); + <span class="kw">let </span>sampler = UniformInt::<u32>::new_inclusive(low, high); + UniformChar { sampler } + } + + <span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="self">Self</span>::X { + <span class="kw">let </span><span class="kw-2">mut </span>x = <span class="self">self</span>.sampler.sample(rng); + <span class="kw">if </span>x >= CHAR_SURROGATE_START { + x += CHAR_SURROGATE_LEN; + } + <span class="comment">// SAFETY: x must not be in surrogate range or greater than char::MAX. + // This relies on range constructors which accept char arguments. + // Validity of input char values is assumed. + </span><span class="kw">unsafe </span>{ core::char::from_u32_unchecked(x) } + } +} + +<span class="doccomment">/// The back-end implementing [`UniformSampler`] for floating-point types. +/// +/// Unless you are implementing [`UniformSampler`] for your own type, this type +/// should not be used directly, use [`Uniform`] instead. +/// +/// # Implementation notes +/// +/// Instead of generating a float in the `[0, 1)` range using [`Standard`], the +/// `UniformFloat` implementation converts the output of an PRNG itself. This +/// way one or two steps can be optimized out. +/// +/// The floats are first converted to a value in the `[1, 2)` interval using a +/// transmute-based method, and then mapped to the expected range with a +/// multiply and addition. Values produced this way have what equals 23 bits of +/// random digits for an `f32`, and 52 for an `f64`. +/// +/// [`new`]: UniformSampler::new +/// [`new_inclusive`]: UniformSampler::new_inclusive +/// [`Standard`]: crate::distributions::Standard +</span><span class="attribute">#[derive(Clone, Copy, Debug, PartialEq)] +#[cfg_attr(feature = <span class="string">"serde1"</span>, derive(Serialize, Deserialize))] +</span><span class="kw">pub struct </span>UniformFloat<X> { + low: X, + scale: X, +} + +<span class="macro">macro_rules! </span>uniform_float_impl { + (<span class="macro-nonterminal">$ty</span>:ty, <span class="macro-nonterminal">$uty</span>:ident, <span class="macro-nonterminal">$f_scalar</span>:ident, <span class="macro-nonterminal">$u_scalar</span>:ident, <span class="macro-nonterminal">$bits_to_discard</span>:expr) => { + <span class="kw">impl </span>SampleUniform <span class="kw">for </span><span class="macro-nonterminal">$ty </span>{ + <span class="kw">type </span>Sampler = UniformFloat<<span class="macro-nonterminal">$ty</span>>; + } + + <span class="kw">impl </span>UniformSampler <span class="kw">for </span>UniformFloat<<span class="macro-nonterminal">$ty</span>> { + <span class="kw">type </span>X = <span class="macro-nonterminal">$ty</span>; + + <span class="kw">fn </span>new<B1, B2>(low_b: B1, high_b: B2) -> <span class="self">Self + </span><span class="kw">where + </span>B1: SampleBorrow<<span class="self">Self</span>::X> + Sized, + B2: SampleBorrow<<span class="self">Self</span>::X> + Sized, + { + <span class="kw">let </span>low = <span class="kw-2">*</span>low_b.borrow(); + <span class="kw">let </span>high = <span class="kw-2">*</span>high_b.borrow(); + <span class="macro">debug_assert!</span>( + low.all_finite(), + <span class="string">"Uniform::new called with `low` non-finite." + </span>); + <span class="macro">debug_assert!</span>( + high.all_finite(), + <span class="string">"Uniform::new called with `high` non-finite." + </span>); + <span class="macro">assert!</span>(low.all_lt(high), <span class="string">"Uniform::new called with `low >= high`"</span>); + <span class="kw">let </span>max_rand = <<span class="macro-nonterminal">$ty</span>>::splat( + (::core::<span class="macro-nonterminal">$u_scalar::MAX </span>>> <span class="macro-nonterminal">$bits_to_discard</span>).into_float_with_exponent(<span class="number">0</span>) - <span class="number">1.0</span>, + ); + + <span class="kw">let </span><span class="kw-2">mut </span>scale = high - low; + <span class="macro">assert!</span>(scale.all_finite(), <span class="string">"Uniform::new: range overflow"</span>); + + <span class="kw">loop </span>{ + <span class="kw">let </span>mask = (scale * max_rand + low).ge_mask(high); + <span class="kw">if </span>mask.none() { + <span class="kw">break</span>; + } + scale = scale.decrease_masked(mask); + } + + <span class="macro">debug_assert!</span>(<<span class="macro-nonterminal">$ty</span>>::splat(<span class="number">0.0</span>).all_le(scale)); + + UniformFloat { low, scale } + } + + <span class="kw">fn </span>new_inclusive<B1, B2>(low_b: B1, high_b: B2) -> <span class="self">Self + </span><span class="kw">where + </span>B1: SampleBorrow<<span class="self">Self</span>::X> + Sized, + B2: SampleBorrow<<span class="self">Self</span>::X> + Sized, + { + <span class="kw">let </span>low = <span class="kw-2">*</span>low_b.borrow(); + <span class="kw">let </span>high = <span class="kw-2">*</span>high_b.borrow(); + <span class="macro">debug_assert!</span>( + low.all_finite(), + <span class="string">"Uniform::new_inclusive called with `low` non-finite." + </span>); + <span class="macro">debug_assert!</span>( + high.all_finite(), + <span class="string">"Uniform::new_inclusive called with `high` non-finite." + </span>); + <span class="macro">assert!</span>( + low.all_le(high), + <span class="string">"Uniform::new_inclusive called with `low > high`" + </span>); + <span class="kw">let </span>max_rand = <<span class="macro-nonterminal">$ty</span>>::splat( + (::core::<span class="macro-nonterminal">$u_scalar::MAX </span>>> <span class="macro-nonterminal">$bits_to_discard</span>).into_float_with_exponent(<span class="number">0</span>) - <span class="number">1.0</span>, + ); + + <span class="kw">let </span><span class="kw-2">mut </span>scale = (high - low) / max_rand; + <span class="macro">assert!</span>(scale.all_finite(), <span class="string">"Uniform::new_inclusive: range overflow"</span>); + + <span class="kw">loop </span>{ + <span class="kw">let </span>mask = (scale * max_rand + low).gt_mask(high); + <span class="kw">if </span>mask.none() { + <span class="kw">break</span>; + } + scale = scale.decrease_masked(mask); + } + + <span class="macro">debug_assert!</span>(<<span class="macro-nonterminal">$ty</span>>::splat(<span class="number">0.0</span>).all_le(scale)); + + UniformFloat { low, scale } + } + + <span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="self">Self</span>::X { + <span class="comment">// Generate a value in the range [1, 2) + </span><span class="kw">let </span>value1_2 = (rng.gen::<<span class="macro-nonterminal">$uty</span>>() >> <span class="macro-nonterminal">$bits_to_discard</span>).into_float_with_exponent(<span class="number">0</span>); + + <span class="comment">// Get a value in the range [0, 1) in order to avoid + // overflowing into infinity when multiplying with scale + </span><span class="kw">let </span>value0_1 = value1_2 - <span class="number">1.0</span>; + + <span class="comment">// We don't use `f64::mul_add`, because it is not available with + // `no_std`. Furthermore, it is slower for some targets (but + // faster for others). However, the order of multiplication and + // addition is important, because on some platforms (e.g. ARM) + // it will be optimized to a single (non-FMA) instruction. + </span>value0_1 * <span class="self">self</span>.scale + <span class="self">self</span>.low + } + + <span class="attribute">#[inline] + </span><span class="kw">fn </span>sample_single<R: Rng + <span class="question-mark">?</span>Sized, B1, B2>(low_b: B1, high_b: B2, rng: <span class="kw-2">&mut </span>R) -> <span class="self">Self</span>::X + <span class="kw">where + </span>B1: SampleBorrow<<span class="self">Self</span>::X> + Sized, + B2: SampleBorrow<<span class="self">Self</span>::X> + Sized, + { + <span class="kw">let </span>low = <span class="kw-2">*</span>low_b.borrow(); + <span class="kw">let </span>high = <span class="kw-2">*</span>high_b.borrow(); + <span class="macro">debug_assert!</span>( + low.all_finite(), + <span class="string">"UniformSampler::sample_single called with `low` non-finite." + </span>); + <span class="macro">debug_assert!</span>( + high.all_finite(), + <span class="string">"UniformSampler::sample_single called with `high` non-finite." + </span>); + <span class="macro">assert!</span>( + low.all_lt(high), + <span class="string">"UniformSampler::sample_single: low >= high" + </span>); + <span class="kw">let </span><span class="kw-2">mut </span>scale = high - low; + <span class="macro">assert!</span>(scale.all_finite(), <span class="string">"UniformSampler::sample_single: range overflow"</span>); + + <span class="kw">loop </span>{ + <span class="comment">// Generate a value in the range [1, 2) + </span><span class="kw">let </span>value1_2 = + (rng.gen::<<span class="macro-nonterminal">$uty</span>>() >> <span class="macro-nonterminal">$bits_to_discard</span>).into_float_with_exponent(<span class="number">0</span>); + + <span class="comment">// Get a value in the range [0, 1) in order to avoid + // overflowing into infinity when multiplying with scale + </span><span class="kw">let </span>value0_1 = value1_2 - <span class="number">1.0</span>; + + <span class="comment">// Doing multiply before addition allows some architectures + // to use a single instruction. + </span><span class="kw">let </span>res = value0_1 * scale + low; + + <span class="macro">debug_assert!</span>(low.all_le(res) || !scale.all_finite()); + <span class="kw">if </span>res.all_lt(high) { + <span class="kw">return </span>res; + } + + <span class="comment">// This handles a number of edge cases. + // * `low` or `high` is NaN. In this case `scale` and + // `res` are going to end up as NaN. + // * `low` is negative infinity and `high` is finite. + // `scale` is going to be infinite and `res` will be + // NaN. + // * `high` is positive infinity and `low` is finite. + // `scale` is going to be infinite and `res` will + // be infinite or NaN (if value0_1 is 0). + // * `low` is negative infinity and `high` is positive + // infinity. `scale` will be infinite and `res` will + // be NaN. + // * `low` and `high` are finite, but `high - low` + // overflows to infinite. `scale` will be infinite + // and `res` will be infinite or NaN (if value0_1 is 0). + // So if `high` or `low` are non-finite, we are guaranteed + // to fail the `res < high` check above and end up here. + // + // While we technically should check for non-finite `low` + // and `high` before entering the loop, by doing the checks + // here instead, we allow the common case to avoid these + // checks. But we are still guaranteed that if `low` or + // `high` are non-finite we'll end up here and can do the + // appropriate checks. + // + // Likewise `high - low` overflowing to infinity is also + // rare, so handle it here after the common case. + </span><span class="kw">let </span>mask = !scale.finite_mask(); + <span class="kw">if </span>mask.any() { + <span class="macro">assert!</span>( + low.all_finite() && high.all_finite(), + <span class="string">"Uniform::sample_single: low and high must be finite" + </span>); + scale = scale.decrease_masked(mask); + } + } + } + } + }; +} + +<span class="macro">uniform_float_impl! </span>{ f32, u32, f32, u32, <span class="number">32 </span>- <span class="number">23 </span>} +<span class="macro">uniform_float_impl! </span>{ f64, u64, f64, u64, <span class="number">64 </span>- <span class="number">52 </span>} + +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="macro">uniform_float_impl! </span>{ f32x2, u32x2, f32, u32, <span class="number">32 </span>- <span class="number">23 </span>} +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="macro">uniform_float_impl! </span>{ f32x4, u32x4, f32, u32, <span class="number">32 </span>- <span class="number">23 </span>} +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="macro">uniform_float_impl! </span>{ f32x8, u32x8, f32, u32, <span class="number">32 </span>- <span class="number">23 </span>} +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="macro">uniform_float_impl! </span>{ f32x16, u32x16, f32, u32, <span class="number">32 </span>- <span class="number">23 </span>} + +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="macro">uniform_float_impl! </span>{ f64x2, u64x2, f64, u64, <span class="number">64 </span>- <span class="number">52 </span>} +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="macro">uniform_float_impl! </span>{ f64x4, u64x4, f64, u64, <span class="number">64 </span>- <span class="number">52 </span>} +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="macro">uniform_float_impl! </span>{ f64x8, u64x8, f64, u64, <span class="number">64 </span>- <span class="number">52 </span>} + + +<span class="doccomment">/// The back-end implementing [`UniformSampler`] for `Duration`. +/// +/// Unless you are implementing [`UniformSampler`] for your own types, this type +/// should not be used directly, use [`Uniform`] instead. +</span><span class="attribute">#[derive(Clone, Copy, Debug)] +#[cfg_attr(feature = <span class="string">"serde1"</span>, derive(Serialize, Deserialize))] +</span><span class="kw">pub struct </span>UniformDuration { + mode: UniformDurationMode, + offset: u32, +} + +<span class="attribute">#[derive(Debug, Copy, Clone)] +#[cfg_attr(feature = <span class="string">"serde1"</span>, derive(Serialize, Deserialize))] +</span><span class="kw">enum </span>UniformDurationMode { + Small { + secs: u64, + nanos: Uniform<u32>, + }, + Medium { + nanos: Uniform<u64>, + }, + Large { + max_secs: u64, + max_nanos: u32, + secs: Uniform<u64>, + }, +} + +<span class="kw">impl </span>SampleUniform <span class="kw">for </span>Duration { + <span class="kw">type </span>Sampler = UniformDuration; +} + +<span class="kw">impl </span>UniformSampler <span class="kw">for </span>UniformDuration { + <span class="kw">type </span>X = Duration; + + <span class="attribute">#[inline] + </span><span class="kw">fn </span>new<B1, B2>(low_b: B1, high_b: B2) -> <span class="self">Self + </span><span class="kw">where + </span>B1: SampleBorrow<<span class="self">Self</span>::X> + Sized, + B2: SampleBorrow<<span class="self">Self</span>::X> + Sized, + { + <span class="kw">let </span>low = <span class="kw-2">*</span>low_b.borrow(); + <span class="kw">let </span>high = <span class="kw-2">*</span>high_b.borrow(); + <span class="macro">assert!</span>(low < high, <span class="string">"Uniform::new called with `low >= high`"</span>); + UniformDuration::new_inclusive(low, high - Duration::new(<span class="number">0</span>, <span class="number">1</span>)) + } + + <span class="attribute">#[inline] + </span><span class="kw">fn </span>new_inclusive<B1, B2>(low_b: B1, high_b: B2) -> <span class="self">Self + </span><span class="kw">where + </span>B1: SampleBorrow<<span class="self">Self</span>::X> + Sized, + B2: SampleBorrow<<span class="self">Self</span>::X> + Sized, + { + <span class="kw">let </span>low = <span class="kw-2">*</span>low_b.borrow(); + <span class="kw">let </span>high = <span class="kw-2">*</span>high_b.borrow(); + <span class="macro">assert!</span>( + low <= high, + <span class="string">"Uniform::new_inclusive called with `low > high`" + </span>); + + <span class="kw">let </span>low_s = low.as_secs(); + <span class="kw">let </span>low_n = low.subsec_nanos(); + <span class="kw">let </span><span class="kw-2">mut </span>high_s = high.as_secs(); + <span class="kw">let </span><span class="kw-2">mut </span>high_n = high.subsec_nanos(); + + <span class="kw">if </span>high_n < low_n { + high_s -= <span class="number">1</span>; + high_n += <span class="number">1_000_000_000</span>; + } + + <span class="kw">let </span>mode = <span class="kw">if </span>low_s == high_s { + UniformDurationMode::Small { + secs: low_s, + nanos: Uniform::new_inclusive(low_n, high_n), + } + } <span class="kw">else </span>{ + <span class="kw">let </span>max = high_s + .checked_mul(<span class="number">1_000_000_000</span>) + .and_then(|n| n.checked_add(u64::from(high_n))); + + <span class="kw">if let </span><span class="prelude-val">Some</span>(higher_bound) = max { + <span class="kw">let </span>lower_bound = low_s * <span class="number">1_000_000_000 </span>+ u64::from(low_n); + UniformDurationMode::Medium { + nanos: Uniform::new_inclusive(lower_bound, higher_bound), + } + } <span class="kw">else </span>{ + <span class="comment">// An offset is applied to simplify generation of nanoseconds + </span><span class="kw">let </span>max_nanos = high_n - low_n; + UniformDurationMode::Large { + max_secs: high_s, + max_nanos, + secs: Uniform::new_inclusive(low_s, high_s), + } + } + }; + UniformDuration { + mode, + offset: low_n, + } + } + + <span class="attribute">#[inline] + </span><span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> Duration { + <span class="kw">match </span><span class="self">self</span>.mode { + UniformDurationMode::Small { secs, nanos } => { + <span class="kw">let </span>n = nanos.sample(rng); + Duration::new(secs, n) + } + UniformDurationMode::Medium { nanos } => { + <span class="kw">let </span>nanos = nanos.sample(rng); + Duration::new(nanos / <span class="number">1_000_000_000</span>, (nanos % <span class="number">1_000_000_000</span>) <span class="kw">as </span>u32) + } + UniformDurationMode::Large { + max_secs, + max_nanos, + secs, + } => { + <span class="comment">// constant folding means this is at least as fast as `Rng::sample(Range)` + </span><span class="kw">let </span>nano_range = Uniform::new(<span class="number">0</span>, <span class="number">1_000_000_000</span>); + <span class="kw">loop </span>{ + <span class="kw">let </span>s = secs.sample(rng); + <span class="kw">let </span>n = nano_range.sample(rng); + <span class="kw">if </span>!(s == max_secs && n > max_nanos) { + <span class="kw">let </span>sum = n + <span class="self">self</span>.offset; + <span class="kw">break </span>Duration::new(s, sum); + } + } + } + } + } +} + +<span class="attribute">#[cfg(test)] +</span><span class="kw">mod </span>tests { + <span class="kw">use super</span>::<span class="kw-2">*</span>; + <span class="kw">use </span><span class="kw">crate</span>::rngs::mock::StepRng; + + <span class="attribute">#[test] + #[cfg(feature = <span class="string">"serde1"</span>)] + </span><span class="kw">fn </span>test_serialization_uniform_duration() { + <span class="kw">let </span>distr = UniformDuration::new(Duration::from_secs(<span class="number">10</span>), Duration::from_secs(<span class="number">60</span>)); + <span class="kw">let </span>de_distr: UniformDuration = bincode::deserialize(<span class="kw-2">&</span>bincode::serialize(<span class="kw-2">&</span>distr).unwrap()).unwrap(); + <span class="macro">assert_eq!</span>( + distr.offset, de_distr.offset + ); + <span class="kw">match </span>(distr.mode, de_distr.mode) { + (UniformDurationMode::Small {secs: a_secs, nanos: a_nanos}, UniformDurationMode::Small {secs, nanos}) => { + <span class="macro">assert_eq!</span>(a_secs, secs); + + <span class="macro">assert_eq!</span>(a_nanos.<span class="number">0</span>.low, nanos.<span class="number">0</span>.low); + <span class="macro">assert_eq!</span>(a_nanos.<span class="number">0</span>.range, nanos.<span class="number">0</span>.range); + <span class="macro">assert_eq!</span>(a_nanos.<span class="number">0</span>.z, nanos.<span class="number">0</span>.z); + } + (UniformDurationMode::Medium {nanos: a_nanos} , UniformDurationMode::Medium {nanos}) => { + <span class="macro">assert_eq!</span>(a_nanos.<span class="number">0</span>.low, nanos.<span class="number">0</span>.low); + <span class="macro">assert_eq!</span>(a_nanos.<span class="number">0</span>.range, nanos.<span class="number">0</span>.range); + <span class="macro">assert_eq!</span>(a_nanos.<span class="number">0</span>.z, nanos.<span class="number">0</span>.z); + } + (UniformDurationMode::Large {max_secs:a_max_secs, max_nanos:a_max_nanos, secs:a_secs}, UniformDurationMode::Large {max_secs, max_nanos, secs} ) => { + <span class="macro">assert_eq!</span>(a_max_secs, max_secs); + <span class="macro">assert_eq!</span>(a_max_nanos, max_nanos); + + <span class="macro">assert_eq!</span>(a_secs.<span class="number">0</span>.low, secs.<span class="number">0</span>.low); + <span class="macro">assert_eq!</span>(a_secs.<span class="number">0</span>.range, secs.<span class="number">0</span>.range); + <span class="macro">assert_eq!</span>(a_secs.<span class="number">0</span>.z, secs.<span class="number">0</span>.z); + } + <span class="kw">_ </span>=> <span class="macro">panic!</span>(<span class="string">"`UniformDurationMode` was not serialized/deserialized correctly"</span>) + } + } + + <span class="attribute">#[test] + #[cfg(feature = <span class="string">"serde1"</span>)] + </span><span class="kw">fn </span>test_uniform_serialization() { + <span class="kw">let </span>unit_box: Uniform<i32> = Uniform::new(-<span class="number">1</span>, <span class="number">1</span>); + <span class="kw">let </span>de_unit_box: Uniform<i32> = bincode::deserialize(<span class="kw-2">&</span>bincode::serialize(<span class="kw-2">&</span>unit_box).unwrap()).unwrap(); + + <span class="macro">assert_eq!</span>(unit_box.<span class="number">0</span>.low, de_unit_box.<span class="number">0</span>.low); + <span class="macro">assert_eq!</span>(unit_box.<span class="number">0</span>.range, de_unit_box.<span class="number">0</span>.range); + <span class="macro">assert_eq!</span>(unit_box.<span class="number">0</span>.z, de_unit_box.<span class="number">0</span>.z); + + <span class="kw">let </span>unit_box: Uniform<f32> = Uniform::new(-<span class="number">1.</span>, <span class="number">1.</span>); + <span class="kw">let </span>de_unit_box: Uniform<f32> = bincode::deserialize(<span class="kw-2">&</span>bincode::serialize(<span class="kw-2">&</span>unit_box).unwrap()).unwrap(); + + <span class="macro">assert_eq!</span>(unit_box.<span class="number">0</span>.low, de_unit_box.<span class="number">0</span>.low); + <span class="macro">assert_eq!</span>(unit_box.<span class="number">0</span>.scale, de_unit_box.<span class="number">0</span>.scale); + } + + <span class="attribute">#[should_panic] + #[test] + </span><span class="kw">fn </span>test_uniform_bad_limits_equal_int() { + Uniform::new(<span class="number">10</span>, <span class="number">10</span>); + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_uniform_good_limits_equal_int() { + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">804</span>); + <span class="kw">let </span>dist = Uniform::new_inclusive(<span class="number">10</span>, <span class="number">10</span>); + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">20 </span>{ + <span class="macro">assert_eq!</span>(rng.sample(dist), <span class="number">10</span>); + } + } + + <span class="attribute">#[should_panic] + #[test] + </span><span class="kw">fn </span>test_uniform_bad_limits_flipped_int() { + Uniform::new(<span class="number">10</span>, <span class="number">5</span>); + } + + <span class="attribute">#[test] + #[cfg_attr(miri, ignore)] </span><span class="comment">// Miri is too slow + </span><span class="kw">fn </span>test_integers() { + <span class="kw">use </span>core::{i128, u128}; + <span class="kw">use </span>core::{i16, i32, i64, i8, isize}; + <span class="kw">use </span>core::{u16, u32, u64, u8, usize}; + + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">251</span>); + <span class="macro">macro_rules! </span>t { + (<span class="macro-nonterminal">$ty</span>:ident, <span class="macro-nonterminal">$v</span>:expr, <span class="macro-nonterminal">$le</span>:expr, <span class="macro-nonterminal">$lt</span>:expr) => {{ + <span class="kw">for </span><span class="kw-2">&</span>(low, high) <span class="kw">in </span><span class="macro-nonterminal">$v</span>.iter() { + <span class="kw">let </span>my_uniform = Uniform::new(low, high); + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">1000 </span>{ + <span class="kw">let </span>v: <span class="macro-nonterminal">$ty </span>= rng.sample(my_uniform); + <span class="macro">assert!</span>(<span class="macro-nonterminal">$le</span>(low, v) && <span class="macro-nonterminal">$lt</span>(v, high)); + } + + <span class="kw">let </span>my_uniform = Uniform::new_inclusive(low, high); + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">1000 </span>{ + <span class="kw">let </span>v: <span class="macro-nonterminal">$ty </span>= rng.sample(my_uniform); + <span class="macro">assert!</span>(<span class="macro-nonterminal">$le</span>(low, v) && <span class="macro-nonterminal">$le</span>(v, high)); + } + + <span class="kw">let </span>my_uniform = Uniform::new(<span class="kw-2">&</span>low, high); + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">1000 </span>{ + <span class="kw">let </span>v: <span class="macro-nonterminal">$ty </span>= rng.sample(my_uniform); + <span class="macro">assert!</span>(<span class="macro-nonterminal">$le</span>(low, v) && <span class="macro-nonterminal">$lt</span>(v, high)); + } + + <span class="kw">let </span>my_uniform = Uniform::new_inclusive(<span class="kw-2">&</span>low, <span class="kw-2">&</span>high); + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">1000 </span>{ + <span class="kw">let </span>v: <span class="macro-nonterminal">$ty </span>= rng.sample(my_uniform); + <span class="macro">assert!</span>(<span class="macro-nonterminal">$le</span>(low, v) && <span class="macro-nonterminal">$le</span>(v, high)); + } + + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">1000 </span>{ + <span class="kw">let </span>v = <<span class="macro-nonterminal">$ty </span><span class="kw">as </span>SampleUniform>::Sampler::sample_single(low, high, <span class="kw-2">&mut </span>rng); + <span class="macro">assert!</span>(<span class="macro-nonterminal">$le</span>(low, v) && <span class="macro-nonterminal">$lt</span>(v, high)); + } + + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">1000 </span>{ + <span class="kw">let </span>v = <<span class="macro-nonterminal">$ty </span><span class="kw">as </span>SampleUniform>::Sampler::sample_single_inclusive(low, high, <span class="kw-2">&mut </span>rng); + <span class="macro">assert!</span>(<span class="macro-nonterminal">$le</span>(low, v) && <span class="macro-nonterminal">$le</span>(v, high)); + } + } + }}; + + <span class="comment">// scalar bulk + </span>($(<span class="macro-nonterminal">$ty</span>:ident),<span class="kw-2">*</span>) => {{ + $(<span class="macro">t!</span>( + <span class="macro-nonterminal">$ty</span>, + [(<span class="number">0</span>, <span class="number">10</span>), (<span class="number">10</span>, <span class="number">127</span>), (<span class="macro-nonterminal">$ty::MIN</span>, <span class="macro-nonterminal">$ty::MAX</span>)], + |x, y| x <= y, + |x, y| x < y + );)* + }}; + + <span class="comment">// simd bulk + </span>($(<span class="macro-nonterminal">$ty</span>:ident),* => <span class="macro-nonterminal">$scalar</span>:ident) => {{ + $(<span class="macro">t!</span>( + <span class="macro-nonterminal">$ty</span>, + [ + (<span class="macro-nonterminal">$ty::splat</span>(<span class="number">0</span>), <span class="macro-nonterminal">$ty::splat</span>(<span class="number">10</span>)), + (<span class="macro-nonterminal">$ty::splat</span>(<span class="number">10</span>), <span class="macro-nonterminal">$ty::splat</span>(<span class="number">127</span>)), + (<span class="macro-nonterminal">$ty::splat</span>(<span class="macro-nonterminal">$scalar::MIN</span>), <span class="macro-nonterminal">$ty::splat</span>(<span class="macro-nonterminal">$scalar::MAX</span>)), + ], + |x: <span class="macro-nonterminal">$ty</span>, y| x.le(y).all(), + |x: <span class="macro-nonterminal">$ty</span>, y| x.lt(y).all() + );)* + }}; + } + <span class="macro">t!</span>(i8, i16, i32, i64, isize, u8, u16, u32, u64, usize, i128, u128); + + <span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] + </span>{ + <span class="macro">t!</span>(u8x2, u8x4, u8x8, u8x16, u8x32, u8x64 => u8); + <span class="macro">t!</span>(i8x2, i8x4, i8x8, i8x16, i8x32, i8x64 => i8); + <span class="macro">t!</span>(u16x2, u16x4, u16x8, u16x16, u16x32 => u16); + <span class="macro">t!</span>(i16x2, i16x4, i16x8, i16x16, i16x32 => i16); + <span class="macro">t!</span>(u32x2, u32x4, u32x8, u32x16 => u32); + <span class="macro">t!</span>(i32x2, i32x4, i32x8, i32x16 => i32); + <span class="macro">t!</span>(u64x2, u64x4, u64x8 => u64); + <span class="macro">t!</span>(i64x2, i64x4, i64x8 => i64); + } + } + + <span class="attribute">#[test] + #[cfg_attr(miri, ignore)] </span><span class="comment">// Miri is too slow + </span><span class="kw">fn </span>test_char() { + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">891</span>); + <span class="kw">let </span><span class="kw-2">mut </span>max = core::char::from_u32(<span class="number">0</span>).unwrap(); + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">100 </span>{ + <span class="kw">let </span>c = rng.gen_range(<span class="string">'A'</span>..=<span class="string">'Z'</span>); + <span class="macro">assert!</span>((<span class="string">'A'</span>..=<span class="string">'Z'</span>).contains(<span class="kw-2">&</span>c)); + max = max.max(c); + } + <span class="macro">assert_eq!</span>(max, <span class="string">'Z'</span>); + <span class="kw">let </span>d = Uniform::new( + core::char::from_u32(<span class="number">0xD7F0</span>).unwrap(), + core::char::from_u32(<span class="number">0xE010</span>).unwrap(), + ); + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">100 </span>{ + <span class="kw">let </span>c = d.sample(<span class="kw-2">&mut </span>rng); + <span class="macro">assert!</span>((c <span class="kw">as </span>u32) < <span class="number">0xD800 </span>|| (c <span class="kw">as </span>u32) > <span class="number">0xDFFF</span>); + } + } + + <span class="attribute">#[test] + #[cfg_attr(miri, ignore)] </span><span class="comment">// Miri is too slow + </span><span class="kw">fn </span>test_floats() { + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">252</span>); + <span class="kw">let </span><span class="kw-2">mut </span>zero_rng = StepRng::new(<span class="number">0</span>, <span class="number">0</span>); + <span class="kw">let </span><span class="kw-2">mut </span>max_rng = StepRng::new(<span class="number">0xffff_ffff_ffff_ffff</span>, <span class="number">0</span>); + <span class="macro">macro_rules! </span>t { + (<span class="macro-nonterminal">$ty</span>:ty, <span class="macro-nonterminal">$f_scalar</span>:ident, <span class="macro-nonterminal">$bits_shifted</span>:expr) => {{ + <span class="kw">let </span>v: <span class="kw-2">&</span>[(<span class="macro-nonterminal">$f_scalar</span>, <span class="macro-nonterminal">$f_scalar</span>)] = <span class="kw-2">&</span>[ + (<span class="number">0.0</span>, <span class="number">100.0</span>), + (-<span class="number">1e35</span>, -<span class="number">1e25</span>), + (<span class="number">1e-35</span>, <span class="number">1e-25</span>), + (-<span class="number">1e35</span>, <span class="number">1e35</span>), + (<<span class="macro-nonterminal">$f_scalar</span>>::from_bits(<span class="number">0</span>), <<span class="macro-nonterminal">$f_scalar</span>>::from_bits(<span class="number">3</span>)), + (-<<span class="macro-nonterminal">$f_scalar</span>>::from_bits(<span class="number">10</span>), -<<span class="macro-nonterminal">$f_scalar</span>>::from_bits(<span class="number">1</span>)), + (-<<span class="macro-nonterminal">$f_scalar</span>>::from_bits(<span class="number">5</span>), <span class="number">0.0</span>), + (-<<span class="macro-nonterminal">$f_scalar</span>>::from_bits(<span class="number">7</span>), -<span class="number">0.0</span>), + (<span class="number">0.1 </span>* ::core::<span class="macro-nonterminal">$f_scalar::MAX</span>, ::core::<span class="macro-nonterminal">$f_scalar::MAX</span>), + (-::core::<span class="macro-nonterminal">$f_scalar::MAX </span>* <span class="number">0.2</span>, ::core::<span class="macro-nonterminal">$f_scalar::MAX </span>* <span class="number">0.7</span>), + ]; + <span class="kw">for </span><span class="kw-2">&</span>(low_scalar, high_scalar) <span class="kw">in </span>v.iter() { + <span class="kw">for </span>lane <span class="kw">in </span><span class="number">0</span>..<<span class="macro-nonterminal">$ty</span>>::lanes() { + <span class="kw">let </span>low = <<span class="macro-nonterminal">$ty</span>>::splat(<span class="number">0.0 </span><span class="kw">as </span><span class="macro-nonterminal">$f_scalar</span>).replace(lane, low_scalar); + <span class="kw">let </span>high = <<span class="macro-nonterminal">$ty</span>>::splat(<span class="number">1.0 </span><span class="kw">as </span><span class="macro-nonterminal">$f_scalar</span>).replace(lane, high_scalar); + <span class="kw">let </span>my_uniform = Uniform::new(low, high); + <span class="kw">let </span>my_incl_uniform = Uniform::new_inclusive(low, high); + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">100 </span>{ + <span class="kw">let </span>v = rng.sample(my_uniform).extract(lane); + <span class="macro">assert!</span>(low_scalar <= v && v < high_scalar); + <span class="kw">let </span>v = rng.sample(my_incl_uniform).extract(lane); + <span class="macro">assert!</span>(low_scalar <= v && v <= high_scalar); + <span class="kw">let </span>v = <<span class="macro-nonterminal">$ty </span><span class="kw">as </span>SampleUniform>::Sampler + ::sample_single(low, high, <span class="kw-2">&mut </span>rng).extract(lane); + <span class="macro">assert!</span>(low_scalar <= v && v < high_scalar); + } + + <span class="macro">assert_eq!</span>( + rng.sample(Uniform::new_inclusive(low, low)).extract(lane), + low_scalar + ); + + <span class="macro">assert_eq!</span>(zero_rng.sample(my_uniform).extract(lane), low_scalar); + <span class="macro">assert_eq!</span>(zero_rng.sample(my_incl_uniform).extract(lane), low_scalar); + <span class="macro">assert_eq!</span>(<<span class="macro-nonterminal">$ty </span><span class="kw">as </span>SampleUniform>::Sampler + ::sample_single(low, high, <span class="kw-2">&mut </span>zero_rng) + .extract(lane), low_scalar); + <span class="macro">assert!</span>(max_rng.sample(my_uniform).extract(lane) < high_scalar); + <span class="macro">assert!</span>(max_rng.sample(my_incl_uniform).extract(lane) <= high_scalar); + + <span class="comment">// Don't run this test for really tiny differences between high and low + // since for those rounding might result in selecting high for a very + // long time. + </span><span class="kw">if </span>(high_scalar - low_scalar) > <span class="number">0.0001 </span>{ + <span class="kw">let </span><span class="kw-2">mut </span>lowering_max_rng = StepRng::new( + <span class="number">0xffff_ffff_ffff_ffff</span>, + (-<span class="number">1i64 </span><< <span class="macro-nonterminal">$bits_shifted</span>) <span class="kw">as </span>u64, + ); + <span class="macro">assert!</span>( + <<span class="macro-nonterminal">$ty </span><span class="kw">as </span>SampleUniform>::Sampler + ::sample_single(low, high, <span class="kw-2">&mut </span>lowering_max_rng) + .extract(lane) < high_scalar + ); + } + } + } + + <span class="macro">assert_eq!</span>( + rng.sample(Uniform::new_inclusive( + ::core::<span class="macro-nonterminal">$f_scalar::MAX</span>, + ::core::<span class="macro-nonterminal">$f_scalar::MAX + </span>)), + ::core::<span class="macro-nonterminal">$f_scalar::MAX + </span>); + <span class="macro">assert_eq!</span>( + rng.sample(Uniform::new_inclusive( + -::core::<span class="macro-nonterminal">$f_scalar::MAX</span>, + -::core::<span class="macro-nonterminal">$f_scalar::MAX + </span>)), + -::core::<span class="macro-nonterminal">$f_scalar::MAX + </span>); + }}; + } + + <span class="macro">t!</span>(f32, f32, <span class="number">32 </span>- <span class="number">23</span>); + <span class="macro">t!</span>(f64, f64, <span class="number">64 </span>- <span class="number">52</span>); + <span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] + </span>{ + <span class="macro">t!</span>(f32x2, f32, <span class="number">32 </span>- <span class="number">23</span>); + <span class="macro">t!</span>(f32x4, f32, <span class="number">32 </span>- <span class="number">23</span>); + <span class="macro">t!</span>(f32x8, f32, <span class="number">32 </span>- <span class="number">23</span>); + <span class="macro">t!</span>(f32x16, f32, <span class="number">32 </span>- <span class="number">23</span>); + <span class="macro">t!</span>(f64x2, f64, <span class="number">64 </span>- <span class="number">52</span>); + <span class="macro">t!</span>(f64x4, f64, <span class="number">64 </span>- <span class="number">52</span>); + <span class="macro">t!</span>(f64x8, f64, <span class="number">64 </span>- <span class="number">52</span>); + } + } + + <span class="attribute">#[test] + #[should_panic] + </span><span class="kw">fn </span>test_float_overflow() { + <span class="kw">let _ </span>= Uniform::from(::core::f64::MIN..::core::f64::MAX); + } + + <span class="attribute">#[test] + #[should_panic] + </span><span class="kw">fn </span>test_float_overflow_single() { + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">252</span>); + rng.gen_range(::core::f64::MIN..::core::f64::MAX); + } + + <span class="attribute">#[test] + #[cfg(all( + feature = <span class="string">"std"</span>, + not(target_arch = <span class="string">"wasm32"</span>), + not(target_arch = <span class="string">"asmjs"</span>) + ))] + </span><span class="kw">fn </span>test_float_assertions() { + <span class="kw">use </span><span class="kw">super</span>::SampleUniform; + <span class="kw">use </span>std::panic::catch_unwind; + <span class="kw">fn </span>range<T: SampleUniform>(low: T, high: T) { + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">253</span>); + T::Sampler::sample_single(low, high, <span class="kw-2">&mut </span>rng); + } + + <span class="macro">macro_rules! </span>t { + (<span class="macro-nonterminal">$ty</span>:ident, <span class="macro-nonterminal">$f_scalar</span>:ident) => {{ + <span class="kw">let </span>v: <span class="kw-2">&</span>[(<span class="macro-nonterminal">$f_scalar</span>, <span class="macro-nonterminal">$f_scalar</span>)] = <span class="kw-2">&</span>[ + (::std::<span class="macro-nonterminal">$f_scalar::NAN</span>, <span class="number">0.0</span>), + (<span class="number">1.0</span>, ::std::<span class="macro-nonterminal">$f_scalar::NAN</span>), + (::std::<span class="macro-nonterminal">$f_scalar::NAN</span>, ::std::<span class="macro-nonterminal">$f_scalar::NAN</span>), + (<span class="number">1.0</span>, <span class="number">0.5</span>), + (::std::<span class="macro-nonterminal">$f_scalar::MAX</span>, -::std::<span class="macro-nonterminal">$f_scalar::MAX</span>), + (::std::<span class="macro-nonterminal">$f_scalar::INFINITY</span>, ::std::<span class="macro-nonterminal">$f_scalar::INFINITY</span>), + ( + ::std::<span class="macro-nonterminal">$f_scalar::NEG_INFINITY</span>, + ::std::<span class="macro-nonterminal">$f_scalar::NEG_INFINITY</span>, + ), + (::std::<span class="macro-nonterminal">$f_scalar::NEG_INFINITY</span>, <span class="number">5.0</span>), + (<span class="number">5.0</span>, ::std::<span class="macro-nonterminal">$f_scalar::INFINITY</span>), + (::std::<span class="macro-nonterminal">$f_scalar::NAN</span>, ::std::<span class="macro-nonterminal">$f_scalar::INFINITY</span>), + (::std::<span class="macro-nonterminal">$f_scalar::NEG_INFINITY</span>, ::std::<span class="macro-nonterminal">$f_scalar::NAN</span>), + (::std::<span class="macro-nonterminal">$f_scalar::NEG_INFINITY</span>, ::std::<span class="macro-nonterminal">$f_scalar::INFINITY</span>), + ]; + <span class="kw">for </span><span class="kw-2">&</span>(low_scalar, high_scalar) <span class="kw">in </span>v.iter() { + <span class="kw">for </span>lane <span class="kw">in </span><span class="number">0</span>..<<span class="macro-nonterminal">$ty</span>>::lanes() { + <span class="kw">let </span>low = <<span class="macro-nonterminal">$ty</span>>::splat(<span class="number">0.0 </span><span class="kw">as </span><span class="macro-nonterminal">$f_scalar</span>).replace(lane, low_scalar); + <span class="kw">let </span>high = <<span class="macro-nonterminal">$ty</span>>::splat(<span class="number">1.0 </span><span class="kw">as </span><span class="macro-nonterminal">$f_scalar</span>).replace(lane, high_scalar); + <span class="macro">assert!</span>(catch_unwind(|| range(low, high)).is_err()); + <span class="macro">assert!</span>(catch_unwind(|| Uniform::new(low, high)).is_err()); + <span class="macro">assert!</span>(catch_unwind(|| Uniform::new_inclusive(low, high)).is_err()); + <span class="macro">assert!</span>(catch_unwind(|| range(low, low)).is_err()); + <span class="macro">assert!</span>(catch_unwind(|| Uniform::new(low, low)).is_err()); + } + } + }}; + } + + <span class="macro">t!</span>(f32, f32); + <span class="macro">t!</span>(f64, f64); + <span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] + </span>{ + <span class="macro">t!</span>(f32x2, f32); + <span class="macro">t!</span>(f32x4, f32); + <span class="macro">t!</span>(f32x8, f32); + <span class="macro">t!</span>(f32x16, f32); + <span class="macro">t!</span>(f64x2, f64); + <span class="macro">t!</span>(f64x4, f64); + <span class="macro">t!</span>(f64x8, f64); + } + } + + + <span class="attribute">#[test] + #[cfg_attr(miri, ignore)] </span><span class="comment">// Miri is too slow + </span><span class="kw">fn </span>test_durations() { + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">253</span>); + + <span class="kw">let </span>v = <span class="kw-2">&</span>[ + (Duration::new(<span class="number">10</span>, <span class="number">50000</span>), Duration::new(<span class="number">100</span>, <span class="number">1234</span>)), + (Duration::new(<span class="number">0</span>, <span class="number">100</span>), Duration::new(<span class="number">1</span>, <span class="number">50</span>)), + ( + Duration::new(<span class="number">0</span>, <span class="number">0</span>), + Duration::new(u64::max_value(), <span class="number">999_999_999</span>), + ), + ]; + <span class="kw">for </span><span class="kw-2">&</span>(low, high) <span class="kw">in </span>v.iter() { + <span class="kw">let </span>my_uniform = Uniform::new(low, high); + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">1000 </span>{ + <span class="kw">let </span>v = rng.sample(my_uniform); + <span class="macro">assert!</span>(low <= v && v < high); + } + } + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_custom_uniform() { + <span class="kw">use </span><span class="kw">crate</span>::distributions::uniform::{ + SampleBorrow, SampleUniform, UniformFloat, UniformSampler, + }; + <span class="attribute">#[derive(Clone, Copy, PartialEq, PartialOrd)] + </span><span class="kw">struct </span>MyF32 { + x: f32, + } + <span class="attribute">#[derive(Clone, Copy, Debug)] + </span><span class="kw">struct </span>UniformMyF32(UniformFloat<f32>); + <span class="kw">impl </span>UniformSampler <span class="kw">for </span>UniformMyF32 { + <span class="kw">type </span>X = MyF32; + + <span class="kw">fn </span>new<B1, B2>(low: B1, high: B2) -> <span class="self">Self + </span><span class="kw">where + </span>B1: SampleBorrow<<span class="self">Self</span>::X> + Sized, + B2: SampleBorrow<<span class="self">Self</span>::X> + Sized, + { + UniformMyF32(UniformFloat::<f32>::new(low.borrow().x, high.borrow().x)) + } + + <span class="kw">fn </span>new_inclusive<B1, B2>(low: B1, high: B2) -> <span class="self">Self + </span><span class="kw">where + </span>B1: SampleBorrow<<span class="self">Self</span>::X> + Sized, + B2: SampleBorrow<<span class="self">Self</span>::X> + Sized, + { + UniformSampler::new(low, high) + } + + <span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="self">Self</span>::X { + MyF32 { + x: <span class="self">self</span>.<span class="number">0</span>.sample(rng), + } + } + } + <span class="kw">impl </span>SampleUniform <span class="kw">for </span>MyF32 { + <span class="kw">type </span>Sampler = UniformMyF32; + } + + <span class="kw">let </span>(low, high) = (MyF32 { x: <span class="number">17.0f32 </span>}, MyF32 { x: <span class="number">22.0f32 </span>}); + <span class="kw">let </span>uniform = Uniform::new(low, high); + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">804</span>); + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">100 </span>{ + <span class="kw">let </span>x: MyF32 = rng.sample(uniform); + <span class="macro">assert!</span>(low <= x && x < high); + } + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_uniform_from_std_range() { + <span class="kw">let </span>r = Uniform::from(<span class="number">2u32</span>..<span class="number">7</span>); + <span class="macro">assert_eq!</span>(r.<span class="number">0</span>.low, <span class="number">2</span>); + <span class="macro">assert_eq!</span>(r.<span class="number">0</span>.range, <span class="number">5</span>); + <span class="kw">let </span>r = Uniform::from(<span class="number">2.0f64</span>..<span class="number">7.0</span>); + <span class="macro">assert_eq!</span>(r.<span class="number">0</span>.low, <span class="number">2.0</span>); + <span class="macro">assert_eq!</span>(r.<span class="number">0</span>.scale, <span class="number">5.0</span>); + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_uniform_from_std_range_inclusive() { + <span class="kw">let </span>r = Uniform::from(<span class="number">2u32</span>..=<span class="number">6</span>); + <span class="macro">assert_eq!</span>(r.<span class="number">0</span>.low, <span class="number">2</span>); + <span class="macro">assert_eq!</span>(r.<span class="number">0</span>.range, <span class="number">5</span>); + <span class="kw">let </span>r = Uniform::from(<span class="number">2.0f64</span>..=<span class="number">7.0</span>); + <span class="macro">assert_eq!</span>(r.<span class="number">0</span>.low, <span class="number">2.0</span>); + <span class="macro">assert!</span>(r.<span class="number">0</span>.scale > <span class="number">5.0</span>); + <span class="macro">assert!</span>(r.<span class="number">0</span>.scale < <span class="number">5.0 </span>+ <span class="number">1e-14</span>); + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>value_stability() { + <span class="kw">fn </span>test_samples<T: SampleUniform + Copy + core::fmt::Debug + PartialEq>( + lb: T, ub: T, expected_single: <span class="kw-2">&</span>[T], expected_multiple: <span class="kw-2">&</span>[T], + ) <span class="kw">where </span>Uniform<T>: Distribution<T> { + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">897</span>); + <span class="kw">let </span><span class="kw-2">mut </span>buf = [lb; <span class="number">3</span>]; + + <span class="kw">for </span>x <span class="kw">in </span><span class="kw-2">&mut </span>buf { + <span class="kw-2">*</span>x = T::Sampler::sample_single(lb, ub, <span class="kw-2">&mut </span>rng); + } + <span class="macro">assert_eq!</span>(<span class="kw-2">&</span>buf, expected_single); + + <span class="kw">let </span>distr = Uniform::new(lb, ub); + <span class="kw">for </span>x <span class="kw">in </span><span class="kw-2">&mut </span>buf { + <span class="kw-2">*</span>x = rng.sample(<span class="kw-2">&</span>distr); + } + <span class="macro">assert_eq!</span>(<span class="kw-2">&</span>buf, expected_multiple); + } + + <span class="comment">// We test on a sub-set of types; possibly we should do more. + // TODO: SIMD types + + </span>test_samples(<span class="number">11u8</span>, <span class="number">219</span>, <span class="kw-2">&</span>[<span class="number">17</span>, <span class="number">66</span>, <span class="number">214</span>], <span class="kw-2">&</span>[<span class="number">181</span>, <span class="number">93</span>, <span class="number">165</span>]); + test_samples(<span class="number">11u32</span>, <span class="number">219</span>, <span class="kw-2">&</span>[<span class="number">17</span>, <span class="number">66</span>, <span class="number">214</span>], <span class="kw-2">&</span>[<span class="number">181</span>, <span class="number">93</span>, <span class="number">165</span>]); + + test_samples(<span class="number">0f32</span>, <span class="number">1e-2f32</span>, <span class="kw-2">&</span>[<span class="number">0.0003070104</span>, <span class="number">0.0026630748</span>, <span class="number">0.00979833</span>], <span class="kw-2">&</span>[ + <span class="number">0.008194133</span>, + <span class="number">0.00398172</span>, + <span class="number">0.007428536</span>, + ]); + test_samples( + -<span class="number">1e10f64</span>, + <span class="number">1e10f64</span>, + <span class="kw-2">&</span>[-<span class="number">4673848682.871551</span>, <span class="number">6388267422.932352</span>, <span class="number">4857075081.198343</span>], + <span class="kw-2">&</span>[<span class="number">1173375212.1808167</span>, <span class="number">1917642852.109581</span>, <span class="number">2365076174.3153973</span>], + ); + + test_samples( + Duration::new(<span class="number">2</span>, <span class="number">0</span>), + Duration::new(<span class="number">4</span>, <span class="number">0</span>), + <span class="kw-2">&</span>[ + Duration::new(<span class="number">2</span>, <span class="number">532615131</span>), + Duration::new(<span class="number">3</span>, <span class="number">638826742</span>), + Duration::new(<span class="number">3</span>, <span class="number">485707508</span>), + ], + <span class="kw-2">&</span>[ + Duration::new(<span class="number">3</span>, <span class="number">117337521</span>), + Duration::new(<span class="number">3</span>, <span class="number">191764285</span>), + Duration::new(<span class="number">3</span>, <span class="number">236507617</span>), + ], + ); + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>uniform_distributions_can_be_compared() { + <span class="macro">assert_eq!</span>(Uniform::new(<span class="number">1.0</span>, <span class="number">2.0</span>), Uniform::new(<span class="number">1.0</span>, <span class="number">2.0</span>)); + + <span class="comment">// To cover UniformInt + </span><span class="macro">assert_eq!</span>(Uniform::new(<span class="number">1 </span><span class="kw">as </span>u32, <span class="number">2 </span><span class="kw">as </span>u32), Uniform::new(<span class="number">1 </span><span class="kw">as </span>u32, <span class="number">2 </span><span class="kw">as </span>u32)); + } +} +</code></pre></div> +</section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="rand" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0 (69f9c33d7 2022-12-12) (Arch Linux rust 1:1.66.0-1)" ></div></body></html>
\ No newline at end of file diff --git a/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/utils.rs.html b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/utils.rs.html new file mode 100644 index 0000000..118f6fa --- /dev/null +++ b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/utils.rs.html @@ -0,0 +1,861 @@ +<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/home/pico/.local/share/cargo/registry/src/github.com-1ecc6299db9ec823/rand-0.8.5/src/distributions/utils.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>utils.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" 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+<span id="410">410</span> +<span id="411">411</span> +<span id="412">412</span> +<span id="413">413</span> +<span id="414">414</span> +<span id="415">415</span> +<span id="416">416</span> +<span id="417">417</span> +<span id="418">418</span> +<span id="419">419</span> +<span id="420">420</span> +<span id="421">421</span> +<span id="422">422</span> +<span id="423">423</span> +<span id="424">424</span> +<span id="425">425</span> +<span id="426">426</span> +<span id="427">427</span> +<span id="428">428</span> +<span id="429">429</span> +</pre><pre class="rust"><code><span class="comment">// Copyright 2018 Developers of the Rand project. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +</span><span class="doccomment">//! Math helper functions + +</span><span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] </span><span class="kw">use </span>packed_simd::<span class="kw-2">*</span>; + + +<span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">trait </span>WideningMultiply<RHS = <span class="self">Self</span>> { + <span class="kw">type </span>Output; + + <span class="kw">fn </span>wmul(<span class="self">self</span>, x: RHS) -> <span class="self">Self</span>::Output; +} + +<span class="macro">macro_rules! </span>wmul_impl { + (<span class="macro-nonterminal">$ty</span>:ty, <span class="macro-nonterminal">$wide</span>:ty, <span class="macro-nonterminal">$shift</span>:expr) => { + <span class="kw">impl </span>WideningMultiply <span class="kw">for </span><span class="macro-nonterminal">$ty </span>{ + <span class="kw">type </span>Output = (<span class="macro-nonterminal">$ty</span>, <span class="macro-nonterminal">$ty</span>); + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>wmul(<span class="self">self</span>, x: <span class="macro-nonterminal">$ty</span>) -> <span class="self">Self</span>::Output { + <span class="kw">let </span>tmp = (<span class="self">self </span><span class="kw">as </span><span class="macro-nonterminal">$wide</span>) * (x <span class="kw">as </span><span class="macro-nonterminal">$wide</span>); + ((tmp >> <span class="macro-nonterminal">$shift</span>) <span class="kw">as </span><span class="macro-nonterminal">$ty</span>, tmp <span class="kw">as </span><span class="macro-nonterminal">$ty</span>) + } + } + }; + + <span class="comment">// simd bulk implementation + </span>($((<span class="macro-nonterminal">$ty</span>:ident, <span class="macro-nonterminal">$wide</span>:ident),)+, <span class="macro-nonterminal">$shift</span>:expr) => { + $( + <span class="kw">impl </span>WideningMultiply <span class="kw">for </span><span class="macro-nonterminal">$ty </span>{ + <span class="kw">type </span>Output = (<span class="macro-nonterminal">$ty</span>, <span class="macro-nonterminal">$ty</span>); + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>wmul(<span class="self">self</span>, x: <span class="macro-nonterminal">$ty</span>) -> <span class="self">Self</span>::Output { + <span class="comment">// For supported vectors, this should compile to a couple + // supported multiply & swizzle instructions (no actual + // casting). + // TODO: optimize + </span><span class="kw">let </span>y: <span class="macro-nonterminal">$wide </span>= <span class="self">self</span>.cast(); + <span class="kw">let </span>x: <span class="macro-nonterminal">$wide </span>= x.cast(); + <span class="kw">let </span>tmp = y * x; + <span class="kw">let </span>hi: <span class="macro-nonterminal">$ty </span>= (tmp >> <span class="macro-nonterminal">$shift</span>).cast(); + <span class="kw">let </span>lo: <span class="macro-nonterminal">$ty </span>= tmp.cast(); + (hi, lo) + } + } + )+ + }; +} +<span class="macro">wmul_impl! </span>{ u8, u16, <span class="number">8 </span>} +<span class="macro">wmul_impl! </span>{ u16, u32, <span class="number">16 </span>} +<span class="macro">wmul_impl! </span>{ u32, u64, <span class="number">32 </span>} +<span class="macro">wmul_impl! </span>{ u64, u128, <span class="number">64 </span>} + +<span class="comment">// This code is a translation of the __mulddi3 function in LLVM's +// compiler-rt. It is an optimised variant of the common method +// `(a + b) * (c + d) = ac + ad + bc + bd`. +// +// For some reason LLVM can optimise the C version very well, but +// keeps shuffling registers in this Rust translation. +</span><span class="macro">macro_rules! </span>wmul_impl_large { + (<span class="macro-nonterminal">$ty</span>:ty, <span class="macro-nonterminal">$half</span>:expr) => { + <span class="kw">impl </span>WideningMultiply <span class="kw">for </span><span class="macro-nonterminal">$ty </span>{ + <span class="kw">type </span>Output = (<span class="macro-nonterminal">$ty</span>, <span class="macro-nonterminal">$ty</span>); + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>wmul(<span class="self">self</span>, b: <span class="macro-nonterminal">$ty</span>) -> <span class="self">Self</span>::Output { + <span class="kw">const </span>LOWER_MASK: <span class="macro-nonterminal">$ty </span>= !<span class="number">0 </span>>> <span class="macro-nonterminal">$half</span>; + <span class="kw">let </span><span class="kw-2">mut </span>low = (<span class="self">self </span>& LOWER_MASK).wrapping_mul(b & LOWER_MASK); + <span class="kw">let </span><span class="kw-2">mut </span>t = low >> <span class="macro-nonterminal">$half</span>; + low &= LOWER_MASK; + t += (<span class="self">self </span>>> <span class="macro-nonterminal">$half</span>).wrapping_mul(b & LOWER_MASK); + low += (t & LOWER_MASK) << <span class="macro-nonterminal">$half</span>; + <span class="kw">let </span><span class="kw-2">mut </span>high = t >> <span class="macro-nonterminal">$half</span>; + t = low >> <span class="macro-nonterminal">$half</span>; + low &= LOWER_MASK; + t += (b >> <span class="macro-nonterminal">$half</span>).wrapping_mul(<span class="self">self </span>& LOWER_MASK); + low += (t & LOWER_MASK) << <span class="macro-nonterminal">$half</span>; + high += t >> <span class="macro-nonterminal">$half</span>; + high += (<span class="self">self </span>>> <span class="macro-nonterminal">$half</span>).wrapping_mul(b >> <span class="macro-nonterminal">$half</span>); + + (high, low) + } + } + }; + + <span class="comment">// simd bulk implementation + </span>(($(<span class="macro-nonterminal">$ty</span>:ty,)+) <span class="macro-nonterminal">$scalar</span>:ty, <span class="macro-nonterminal">$half</span>:expr) => { + $( + <span class="kw">impl </span>WideningMultiply <span class="kw">for </span><span class="macro-nonterminal">$ty </span>{ + <span class="kw">type </span>Output = (<span class="macro-nonterminal">$ty</span>, <span class="macro-nonterminal">$ty</span>); + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>wmul(<span class="self">self</span>, b: <span class="macro-nonterminal">$ty</span>) -> <span class="self">Self</span>::Output { + <span class="comment">// needs wrapping multiplication + </span><span class="kw">const </span>LOWER_MASK: <span class="macro-nonterminal">$scalar </span>= !<span class="number">0 </span>>> <span class="macro-nonterminal">$half</span>; + <span class="kw">let </span><span class="kw-2">mut </span>low = (<span class="self">self </span>& LOWER_MASK) * (b & LOWER_MASK); + <span class="kw">let </span><span class="kw-2">mut </span>t = low >> <span class="macro-nonterminal">$half</span>; + low &= LOWER_MASK; + t += (<span class="self">self </span>>> <span class="macro-nonterminal">$half</span>) * (b & LOWER_MASK); + low += (t & LOWER_MASK) << <span class="macro-nonterminal">$half</span>; + <span class="kw">let </span><span class="kw-2">mut </span>high = t >> <span class="macro-nonterminal">$half</span>; + t = low >> <span class="macro-nonterminal">$half</span>; + low &= LOWER_MASK; + t += (b >> <span class="macro-nonterminal">$half</span>) * (<span class="self">self </span>& LOWER_MASK); + low += (t & LOWER_MASK) << <span class="macro-nonterminal">$half</span>; + high += t >> <span class="macro-nonterminal">$half</span>; + high += (<span class="self">self </span>>> <span class="macro-nonterminal">$half</span>) * (b >> <span class="macro-nonterminal">$half</span>); + + (high, low) + } + } + )+ + }; +} +<span class="macro">wmul_impl_large! </span>{ u128, <span class="number">64 </span>} + +<span class="macro">macro_rules! </span>wmul_impl_usize { + (<span class="macro-nonterminal">$ty</span>:ty) => { + <span class="kw">impl </span>WideningMultiply <span class="kw">for </span>usize { + <span class="kw">type </span>Output = (usize, usize); + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>wmul(<span class="self">self</span>, x: usize) -> <span class="self">Self</span>::Output { + <span class="kw">let </span>(high, low) = (<span class="self">self </span><span class="kw">as </span><span class="macro-nonterminal">$ty</span>).wmul(x <span class="kw">as </span><span class="macro-nonterminal">$ty</span>); + (high <span class="kw">as </span>usize, low <span class="kw">as </span>usize) + } + } + }; +} +<span class="attribute">#[cfg(target_pointer_width = <span class="string">"16"</span>)] +</span><span class="macro">wmul_impl_usize! </span>{ u16 } +<span class="attribute">#[cfg(target_pointer_width = <span class="string">"32"</span>)] +</span><span class="macro">wmul_impl_usize! </span>{ u32 } +<span class="attribute">#[cfg(target_pointer_width = <span class="string">"64"</span>)] +</span><span class="macro">wmul_impl_usize! </span>{ u64 } + +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="kw">mod </span>simd_wmul { + <span class="kw">use super</span>::<span class="kw-2">*</span>; + <span class="attribute">#[cfg(target_arch = <span class="string">"x86"</span>)] </span><span class="kw">use </span>core::arch::x86::<span class="kw-2">*</span>; + <span class="attribute">#[cfg(target_arch = <span class="string">"x86_64"</span>)] </span><span class="kw">use </span>core::arch::x86_64::<span class="kw-2">*</span>; + + <span class="macro">wmul_impl! </span>{ + (u8x2, u16x2), + (u8x4, u16x4), + (u8x8, u16x8), + (u8x16, u16x16), + (u8x32, u16x32),, + <span class="number">8 + </span>} + + <span class="macro">wmul_impl! </span>{ (u16x2, u32x2),, <span class="number">16 </span>} + <span class="macro">wmul_impl! </span>{ (u16x4, u32x4),, <span class="number">16 </span>} + <span class="attribute">#[cfg(not(target_feature = <span class="string">"sse2"</span>))] + </span><span class="macro">wmul_impl! </span>{ (u16x8, u32x8),, <span class="number">16 </span>} + <span class="attribute">#[cfg(not(target_feature = <span class="string">"avx2"</span>))] + </span><span class="macro">wmul_impl! </span>{ (u16x16, u32x16),, <span class="number">16 </span>} + + <span class="comment">// 16-bit lane widths allow use of the x86 `mulhi` instructions, which + // means `wmul` can be implemented with only two instructions. + </span><span class="attribute">#[allow(unused_macros)] + </span><span class="macro">macro_rules! </span>wmul_impl_16 { + (<span class="macro-nonterminal">$ty</span>:ident, <span class="macro-nonterminal">$intrinsic</span>:ident, <span class="macro-nonterminal">$mulhi</span>:ident, <span class="macro-nonterminal">$mullo</span>:ident) => { + <span class="kw">impl </span>WideningMultiply <span class="kw">for </span><span class="macro-nonterminal">$ty </span>{ + <span class="kw">type </span>Output = (<span class="macro-nonterminal">$ty</span>, <span class="macro-nonterminal">$ty</span>); + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>wmul(<span class="self">self</span>, x: <span class="macro-nonterminal">$ty</span>) -> <span class="self">Self</span>::Output { + <span class="kw">let </span>b = <span class="macro-nonterminal">$intrinsic::from_bits</span>(x); + <span class="kw">let </span>a = <span class="macro-nonterminal">$intrinsic::from_bits</span>(<span class="self">self</span>); + <span class="kw">let </span>hi = <span class="macro-nonterminal">$ty::from_bits</span>(<span class="kw">unsafe </span>{ <span class="macro-nonterminal">$mulhi</span>(a, b) }); + <span class="kw">let </span>lo = <span class="macro-nonterminal">$ty::from_bits</span>(<span class="kw">unsafe </span>{ <span class="macro-nonterminal">$mullo</span>(a, b) }); + (hi, lo) + } + } + }; + } + + <span class="attribute">#[cfg(target_feature = <span class="string">"sse2"</span>)] + </span><span class="macro">wmul_impl_16! </span>{ u16x8, __m128i, _mm_mulhi_epu16, _mm_mullo_epi16 } + <span class="attribute">#[cfg(target_feature = <span class="string">"avx2"</span>)] + </span><span class="macro">wmul_impl_16! </span>{ u16x16, __m256i, _mm256_mulhi_epu16, _mm256_mullo_epi16 } + <span class="comment">// FIXME: there are no `__m512i` types in stdsimd yet, so `wmul::<u16x32>` + // cannot use the same implementation. + + </span><span class="macro">wmul_impl! </span>{ + (u32x2, u64x2), + (u32x4, u64x4), + (u32x8, u64x8),, + <span class="number">32 + </span>} + + <span class="comment">// TODO: optimize, this seems to seriously slow things down + </span><span class="macro">wmul_impl_large! </span>{ (u8x64,) u8, <span class="number">4 </span>} + <span class="macro">wmul_impl_large! </span>{ (u16x32,) u16, <span class="number">8 </span>} + <span class="macro">wmul_impl_large! </span>{ (u32x16,) u32, <span class="number">16 </span>} + <span class="macro">wmul_impl_large! </span>{ (u64x2, u64x4, u64x8,) u64, <span class="number">32 </span>} +} + +<span class="doccomment">/// Helper trait when dealing with scalar and SIMD floating point types. +</span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">trait </span>FloatSIMDUtils { + <span class="comment">// `PartialOrd` for vectors compares lexicographically. We want to compare all + // the individual SIMD lanes instead, and get the combined result over all + // lanes. This is possible using something like `a.lt(b).all()`, but we + // implement it as a trait so we can write the same code for `f32` and `f64`. + // Only the comparison functions we need are implemented. + </span><span class="kw">fn </span>all_lt(<span class="self">self</span>, other: <span class="self">Self</span>) -> bool; + <span class="kw">fn </span>all_le(<span class="self">self</span>, other: <span class="self">Self</span>) -> bool; + <span class="kw">fn </span>all_finite(<span class="self">self</span>) -> bool; + + <span class="kw">type </span>Mask; + <span class="kw">fn </span>finite_mask(<span class="self">self</span>) -> <span class="self">Self</span>::Mask; + <span class="kw">fn </span>gt_mask(<span class="self">self</span>, other: <span class="self">Self</span>) -> <span class="self">Self</span>::Mask; + <span class="kw">fn </span>ge_mask(<span class="self">self</span>, other: <span class="self">Self</span>) -> <span class="self">Self</span>::Mask; + + <span class="comment">// Decrease all lanes where the mask is `true` to the next lower value + // representable by the floating-point type. At least one of the lanes + // must be set. + </span><span class="kw">fn </span>decrease_masked(<span class="self">self</span>, mask: <span class="self">Self</span>::Mask) -> <span class="self">Self</span>; + + <span class="comment">// Convert from int value. Conversion is done while retaining the numerical + // value, not by retaining the binary representation. + </span><span class="kw">type </span>UInt; + <span class="kw">fn </span>cast_from_int(i: <span class="self">Self</span>::UInt) -> <span class="self">Self</span>; +} + +<span class="doccomment">/// Implement functions available in std builds but missing from core primitives +</span><span class="attribute">#[cfg(not(std))] +</span><span class="comment">// False positive: We are following `std` here. +</span><span class="attribute">#[allow(clippy::wrong_self_convention)] +</span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">trait </span>Float: Sized { + <span class="kw">fn </span>is_nan(<span class="self">self</span>) -> bool; + <span class="kw">fn </span>is_infinite(<span class="self">self</span>) -> bool; + <span class="kw">fn </span>is_finite(<span class="self">self</span>) -> bool; +} + +<span class="doccomment">/// Implement functions on f32/f64 to give them APIs similar to SIMD types +</span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">trait </span>FloatAsSIMD: Sized { + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>lanes() -> usize { + <span class="number">1 + </span>} + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>splat(scalar: <span class="self">Self</span>) -> <span class="self">Self </span>{ + scalar + } + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>extract(<span class="self">self</span>, index: usize) -> <span class="self">Self </span>{ + <span class="macro">debug_assert_eq!</span>(index, <span class="number">0</span>); + <span class="self">self + </span>} + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>replace(<span class="self">self</span>, index: usize, new_value: <span class="self">Self</span>) -> <span class="self">Self </span>{ + <span class="macro">debug_assert_eq!</span>(index, <span class="number">0</span>); + new_value + } +} + +<span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">trait </span>BoolAsSIMD: Sized { + <span class="kw">fn </span>any(<span class="self">self</span>) -> bool; + <span class="kw">fn </span>all(<span class="self">self</span>) -> bool; + <span class="kw">fn </span>none(<span class="self">self</span>) -> bool; +} + +<span class="kw">impl </span>BoolAsSIMD <span class="kw">for </span>bool { + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>any(<span class="self">self</span>) -> bool { + <span class="self">self + </span>} + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>all(<span class="self">self</span>) -> bool { + <span class="self">self + </span>} + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>none(<span class="self">self</span>) -> bool { + !<span class="self">self + </span>} +} + +<span class="macro">macro_rules! </span>scalar_float_impl { + (<span class="macro-nonterminal">$ty</span>:ident, <span class="macro-nonterminal">$uty</span>:ident) => { + <span class="attribute">#[cfg(not(std))] + </span><span class="kw">impl </span>Float <span class="kw">for </span><span class="macro-nonterminal">$ty </span>{ + <span class="attribute">#[inline] + </span><span class="kw">fn </span>is_nan(<span class="self">self</span>) -> bool { + <span class="self">self </span>!= <span class="self">self + </span>} + + <span class="attribute">#[inline] + </span><span class="kw">fn </span>is_infinite(<span class="self">self</span>) -> bool { + <span class="self">self </span>== ::core::<span class="macro-nonterminal">$ty::INFINITY </span>|| <span class="self">self </span>== ::core::<span class="macro-nonterminal">$ty::NEG_INFINITY + </span>} + + <span class="attribute">#[inline] + </span><span class="kw">fn </span>is_finite(<span class="self">self</span>) -> bool { + !(<span class="self">self</span>.is_nan() || <span class="self">self</span>.is_infinite()) + } + } + + <span class="kw">impl </span>FloatSIMDUtils <span class="kw">for </span><span class="macro-nonterminal">$ty </span>{ + <span class="kw">type </span>Mask = bool; + <span class="kw">type </span>UInt = <span class="macro-nonterminal">$uty</span>; + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>all_lt(<span class="self">self</span>, other: <span class="self">Self</span>) -> bool { + <span class="self">self </span>< other + } + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>all_le(<span class="self">self</span>, other: <span class="self">Self</span>) -> bool { + <span class="self">self </span><= other + } + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>all_finite(<span class="self">self</span>) -> bool { + <span class="self">self</span>.is_finite() + } + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>finite_mask(<span class="self">self</span>) -> <span class="self">Self</span>::Mask { + <span class="self">self</span>.is_finite() + } + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>gt_mask(<span class="self">self</span>, other: <span class="self">Self</span>) -> <span class="self">Self</span>::Mask { + <span class="self">self </span>> other + } + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>ge_mask(<span class="self">self</span>, other: <span class="self">Self</span>) -> <span class="self">Self</span>::Mask { + <span class="self">self </span>>= other + } + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>decrease_masked(<span class="self">self</span>, mask: <span class="self">Self</span>::Mask) -> <span class="self">Self </span>{ + <span class="macro">debug_assert!</span>(mask, <span class="string">"At least one lane must be set"</span>); + <<span class="macro-nonterminal">$ty</span>>::from_bits(<span class="self">self</span>.to_bits() - <span class="number">1</span>) + } + + <span class="attribute">#[inline] + </span><span class="kw">fn </span>cast_from_int(i: <span class="self">Self</span>::UInt) -> <span class="self">Self </span>{ + i <span class="kw">as </span><span class="macro-nonterminal">$ty + </span>} + } + + <span class="kw">impl </span>FloatAsSIMD <span class="kw">for </span><span class="macro-nonterminal">$ty </span>{} + }; +} + +<span class="macro">scalar_float_impl!</span>(f32, u32); +<span class="macro">scalar_float_impl!</span>(f64, u64); + + +<span class="attribute">#[cfg(feature = <span class="string">"simd_support"</span>)] +</span><span class="macro">macro_rules! </span>simd_impl { + (<span class="macro-nonterminal">$ty</span>:ident, <span class="macro-nonterminal">$f_scalar</span>:ident, <span class="macro-nonterminal">$mty</span>:ident, <span class="macro-nonterminal">$uty</span>:ident) => { + <span class="kw">impl </span>FloatSIMDUtils <span class="kw">for </span><span class="macro-nonterminal">$ty </span>{ + <span class="kw">type </span>Mask = <span class="macro-nonterminal">$mty</span>; + <span class="kw">type </span>UInt = <span class="macro-nonterminal">$uty</span>; + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>all_lt(<span class="self">self</span>, other: <span class="self">Self</span>) -> bool { + <span class="self">self</span>.lt(other).all() + } + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>all_le(<span class="self">self</span>, other: <span class="self">Self</span>) -> bool { + <span class="self">self</span>.le(other).all() + } + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>all_finite(<span class="self">self</span>) -> bool { + <span class="self">self</span>.finite_mask().all() + } + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>finite_mask(<span class="self">self</span>) -> <span class="self">Self</span>::Mask { + <span class="comment">// This can possibly be done faster by checking bit patterns + </span><span class="kw">let </span>neg_inf = <span class="macro-nonterminal">$ty::splat</span>(::core::<span class="macro-nonterminal">$f_scalar::NEG_INFINITY</span>); + <span class="kw">let </span>pos_inf = <span class="macro-nonterminal">$ty::splat</span>(::core::<span class="macro-nonterminal">$f_scalar::INFINITY</span>); + <span class="self">self</span>.gt(neg_inf) & <span class="self">self</span>.lt(pos_inf) + } + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>gt_mask(<span class="self">self</span>, other: <span class="self">Self</span>) -> <span class="self">Self</span>::Mask { + <span class="self">self</span>.gt(other) + } + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>ge_mask(<span class="self">self</span>, other: <span class="self">Self</span>) -> <span class="self">Self</span>::Mask { + <span class="self">self</span>.ge(other) + } + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>decrease_masked(<span class="self">self</span>, mask: <span class="self">Self</span>::Mask) -> <span class="self">Self </span>{ + <span class="comment">// Casting a mask into ints will produce all bits set for + // true, and 0 for false. Adding that to the binary + // representation of a float means subtracting one from + // the binary representation, resulting in the next lower + // value representable by $ty. This works even when the + // current value is infinity. + </span><span class="macro">debug_assert!</span>(mask.any(), <span class="string">"At least one lane must be set"</span>); + <<span class="macro-nonterminal">$ty</span>>::from_bits(<<span class="macro-nonterminal">$uty</span>>::from_bits(<span class="self">self</span>) + <<span class="macro-nonterminal">$uty</span>>::from_bits(mask)) + } + + <span class="attribute">#[inline] + </span><span class="kw">fn </span>cast_from_int(i: <span class="self">Self</span>::UInt) -> <span class="self">Self </span>{ + i.cast() + } + } + }; +} + +<span class="attribute">#[cfg(feature=<span class="string">"simd_support"</span>)] </span><span class="macro">simd_impl! </span>{ f32x2, f32, m32x2, u32x2 } +<span class="attribute">#[cfg(feature=<span class="string">"simd_support"</span>)] </span><span class="macro">simd_impl! </span>{ f32x4, f32, m32x4, u32x4 } +<span class="attribute">#[cfg(feature=<span class="string">"simd_support"</span>)] </span><span class="macro">simd_impl! </span>{ f32x8, f32, m32x8, u32x8 } +<span class="attribute">#[cfg(feature=<span class="string">"simd_support"</span>)] </span><span class="macro">simd_impl! </span>{ f32x16, f32, m32x16, u32x16 } +<span class="attribute">#[cfg(feature=<span class="string">"simd_support"</span>)] </span><span class="macro">simd_impl! </span>{ f64x2, f64, m64x2, u64x2 } +<span class="attribute">#[cfg(feature=<span class="string">"simd_support"</span>)] </span><span class="macro">simd_impl! </span>{ f64x4, f64, m64x4, u64x4 } +<span class="attribute">#[cfg(feature=<span class="string">"simd_support"</span>)] </span><span class="macro">simd_impl! </span>{ f64x8, f64, m64x8, u64x8 } +</code></pre></div> +</section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="rand" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0 (69f9c33d7 2022-12-12) (Arch Linux rust 1:1.66.0-1)" ></div></body></html>
\ No newline at end of file diff --git a/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/weighted.rs.html b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/weighted.rs.html new file mode 100644 index 0000000..7ae8d0d --- /dev/null +++ b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/weighted.rs.html @@ -0,0 +1,97 @@ +<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/home/pico/.local/share/cargo/registry/src/github.com-1ecc6299db9ec823/rand-0.8.5/src/distributions/weighted.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>weighted.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../../normalize.css"><link rel="stylesheet" href="../../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../../ayu.css" disabled><link rel="stylesheet" href="../../../dark.css" disabled><link rel="stylesheet" href="../../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../../storage.js"></script><script defer src="../../../source-script.js"></script><script defer src="../../../source-files.js"></script><script defer src="../../../main.js"></script><noscript><link rel="stylesheet" href="../../../noscript.css"></noscript><link rel="icon" href="https://www.rust-lang.org/favicon.ico"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../../rand/index.html"> + <img src="https://www.rust-lang.org/logos/rust-logo-128x128-blk.png" alt="logo"></a><form class="search-form"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../../wheel.svg"></a></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> +<span id="2">2</span> +<span id="3">3</span> +<span id="4">4</span> +<span id="5">5</span> +<span id="6">6</span> +<span id="7">7</span> +<span id="8">8</span> +<span id="9">9</span> +<span id="10">10</span> +<span id="11">11</span> +<span id="12">12</span> +<span id="13">13</span> +<span id="14">14</span> +<span id="15">15</span> +<span id="16">16</span> +<span id="17">17</span> +<span id="18">18</span> +<span id="19">19</span> +<span id="20">20</span> +<span id="21">21</span> +<span id="22">22</span> +<span id="23">23</span> +<span id="24">24</span> +<span id="25">25</span> +<span id="26">26</span> +<span id="27">27</span> +<span id="28">28</span> +<span id="29">29</span> +<span id="30">30</span> +<span id="31">31</span> +<span id="32">32</span> +<span id="33">33</span> +<span id="34">34</span> +<span id="35">35</span> +<span id="36">36</span> +<span id="37">37</span> +<span id="38">38</span> +<span id="39">39</span> +<span id="40">40</span> +<span id="41">41</span> +<span id="42">42</span> +<span id="43">43</span> +<span id="44">44</span> +<span id="45">45</span> +<span id="46">46</span> +<span id="47">47</span> +</pre><pre class="rust"><code><span class="comment">// Copyright 2018 Developers of the Rand project. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +</span><span class="doccomment">//! Weighted index sampling +//! +//! This module is deprecated. Use [`crate::distributions::WeightedIndex`] and +//! [`crate::distributions::WeightedError`] instead. + +</span><span class="kw">pub use super</span>::{WeightedIndex, WeightedError}; + +<span class="attribute">#[allow(missing_docs)] +#[deprecated(since = <span class="string">"0.8.0"</span>, note = <span class="string">"moved to rand_distr crate"</span>)] +</span><span class="kw">pub mod </span>alias_method { + <span class="comment">// This module exists to provide a deprecation warning which minimises + // compile errors, but still fails to compile if ever used. + </span><span class="kw">use </span>core::marker::PhantomData; + <span class="kw">use </span>alloc::vec::Vec; + <span class="kw">use </span><span class="kw">super</span>::WeightedError; + + <span class="attribute">#[derive(Debug)] + </span><span class="kw">pub struct </span>WeightedIndex<W: Weight> { + _phantom: PhantomData<W>, + } + <span class="kw">impl</span><W: Weight> WeightedIndex<W> { + <span class="kw">pub fn </span>new(_weights: Vec<W>) -> <span class="prelude-ty">Result</span><<span class="self">Self</span>, WeightedError> { + <span class="prelude-val">Err</span>(WeightedError::NoItem) + } + } + + <span class="kw">pub trait </span>Weight {} + <span class="macro">macro_rules! </span>impl_weight { + () => {}; + (<span class="macro-nonterminal">$T</span>:ident, $(<span class="macro-nonterminal">$more</span>:ident,)<span class="kw-2">*</span>) => { + <span class="kw">impl </span>Weight <span class="kw">for </span><span class="macro-nonterminal">$T </span>{} + <span class="macro">impl_weight!</span>($(<span class="macro-nonterminal">$more</span>,)<span class="kw-2">*</span>); + }; + } + <span class="macro">impl_weight!</span>(f64, f32,); + <span class="macro">impl_weight!</span>(u8, u16, u32, u64, usize,); + <span class="macro">impl_weight!</span>(i8, i16, i32, i64, isize,); + <span class="macro">impl_weight!</span>(u128, i128,); +} +</code></pre></div> +</section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="rand" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0 (69f9c33d7 2022-12-12) (Arch Linux rust 1:1.66.0-1)" ></div></body></html>
\ No newline at end of file diff --git a/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/weighted_index.rs.html b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/weighted_index.rs.html new file mode 100644 index 0000000..7439a5b --- /dev/null +++ b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/distributions/weighted_index.rs.html @@ -0,0 +1,919 @@ +<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/home/pico/.local/share/cargo/registry/src/github.com-1ecc6299db9ec823/rand-0.8.5/src/distributions/weighted_index.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>weighted_index.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../../normalize.css"><link rel="stylesheet" href="../../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../../ayu.css" disabled><link rel="stylesheet" href="../../../dark.css" disabled><link rel="stylesheet" href="../../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../../storage.js"></script><script defer src="../../../source-script.js"></script><script defer src="../../../source-files.js"></script><script defer src="../../../main.js"></script><noscript><link rel="stylesheet" href="../../../noscript.css"></noscript><link rel="icon" href="https://www.rust-lang.org/favicon.ico"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../../rand/index.html"> + <img src="https://www.rust-lang.org/logos/rust-logo-128x128-blk.png" alt="logo"></a><form class="search-form"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../../wheel.svg"></a></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> +<span id="2">2</span> +<span id="3">3</span> +<span id="4">4</span> +<span id="5">5</span> +<span id="6">6</span> +<span id="7">7</span> +<span id="8">8</span> +<span id="9">9</span> +<span id="10">10</span> +<span id="11">11</span> +<span id="12">12</span> +<span id="13">13</span> +<span id="14">14</span> +<span id="15">15</span> +<span id="16">16</span> +<span id="17">17</span> +<span id="18">18</span> +<span id="19">19</span> +<span id="20">20</span> +<span id="21">21</span> +<span id="22">22</span> +<span id="23">23</span> +<span id="24">24</span> +<span id="25">25</span> +<span id="26">26</span> +<span id="27">27</span> +<span id="28">28</span> +<span id="29">29</span> +<span id="30">30</span> +<span id="31">31</span> +<span id="32">32</span> +<span id="33">33</span> +<span id="34">34</span> +<span id="35">35</span> +<span id="36">36</span> +<span id="37">37</span> +<span id="38">38</span> +<span id="39">39</span> +<span id="40">40</span> +<span id="41">41</span> +<span id="42">42</span> +<span id="43">43</span> +<span id="44">44</span> +<span id="45">45</span> +<span id="46">46</span> +<span id="47">47</span> +<span id="48">48</span> +<span id="49">49</span> +<span id="50">50</span> +<span id="51">51</span> +<span id="52">52</span> +<span id="53">53</span> +<span id="54">54</span> +<span id="55">55</span> +<span id="56">56</span> +<span id="57">57</span> +<span id="58">58</span> +<span id="59">59</span> +<span id="60">60</span> +<span id="61">61</span> +<span id="62">62</span> +<span id="63">63</span> +<span id="64">64</span> +<span id="65">65</span> +<span id="66">66</span> +<span id="67">67</span> +<span id="68">68</span> +<span id="69">69</span> +<span id="70">70</span> +<span id="71">71</span> 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This file may not be copied, modified, or distributed +// except according to those terms. + +</span><span class="doccomment">//! Weighted index sampling + +</span><span class="kw">use </span><span class="kw">crate</span>::distributions::uniform::{SampleBorrow, SampleUniform, UniformSampler}; +<span class="kw">use </span><span class="kw">crate</span>::distributions::Distribution; +<span class="kw">use </span><span class="kw">crate</span>::Rng; +<span class="kw">use </span>core::cmp::PartialOrd; +<span class="kw">use </span>core::fmt; + +<span class="comment">// Note that this whole module is only imported if feature="alloc" is enabled. +</span><span class="kw">use </span>alloc::vec::Vec; + +<span class="attribute">#[cfg(feature = <span class="string">"serde1"</span>)] +</span><span class="kw">use </span>serde::{Serialize, Deserialize}; + +<span class="doccomment">/// A distribution using weighted sampling of discrete items +/// +/// Sampling a `WeightedIndex` distribution returns the index of a randomly +/// selected element from the iterator used when the `WeightedIndex` was +/// created. The chance of a given element being picked is proportional to the +/// value of the element. The weights can use any type `X` for which an +/// implementation of [`Uniform<X>`] exists. +/// +/// # Performance +/// +/// Time complexity of sampling from `WeightedIndex` is `O(log N)` where +/// `N` is the number of weights. As an alternative, +/// [`rand_distr::weighted_alias`](https://docs.rs/rand_distr/*/rand_distr/weighted_alias/index.html) +/// supports `O(1)` sampling, but with much higher initialisation cost. +/// +/// A `WeightedIndex<X>` contains a `Vec<X>` and a [`Uniform<X>`] and so its +/// size is the sum of the size of those objects, possibly plus some alignment. +/// +/// Creating a `WeightedIndex<X>` will allocate enough space to hold `N - 1` +/// weights of type `X`, where `N` is the number of weights. However, since +/// `Vec` doesn't guarantee a particular growth strategy, additional memory +/// might be allocated but not used. Since the `WeightedIndex` object also +/// contains, this might cause additional allocations, though for primitive +/// types, [`Uniform<X>`] doesn't allocate any memory. +/// +/// Sampling from `WeightedIndex` will result in a single call to +/// `Uniform<X>::sample` (method of the [`Distribution`] trait), which typically +/// will request a single value from the underlying [`RngCore`], though the +/// exact number depends on the implementation of `Uniform<X>::sample`. +/// +/// # Example +/// +/// ``` +/// use rand::prelude::*; +/// use rand::distributions::WeightedIndex; +/// +/// let choices = ['a', 'b', 'c']; +/// let weights = [2, 1, 1]; +/// let dist = WeightedIndex::new(&weights).unwrap(); +/// let mut rng = thread_rng(); +/// for _ in 0..100 { +/// // 50% chance to print 'a', 25% chance to print 'b', 25% chance to print 'c' +/// println!("{}", choices[dist.sample(&mut rng)]); +/// } +/// +/// let items = [('a', 0), ('b', 3), ('c', 7)]; +/// let dist2 = WeightedIndex::new(items.iter().map(|item| item.1)).unwrap(); +/// for _ in 0..100 { +/// // 0% chance to print 'a', 30% chance to print 'b', 70% chance to print 'c' +/// println!("{}", items[dist2.sample(&mut rng)].0); +/// } +/// ``` +/// +/// [`Uniform<X>`]: crate::distributions::Uniform +/// [`RngCore`]: crate::RngCore +</span><span class="attribute">#[derive(Debug, Clone, PartialEq)] +#[cfg_attr(feature = <span class="string">"serde1"</span>, derive(Serialize, Deserialize))] +#[cfg_attr(doc_cfg, doc(cfg(feature = <span class="string">"alloc"</span>)))] +</span><span class="kw">pub struct </span>WeightedIndex<X: SampleUniform + PartialOrd> { + cumulative_weights: Vec<X>, + total_weight: X, + weight_distribution: X::Sampler, +} + +<span class="kw">impl</span><X: SampleUniform + PartialOrd> WeightedIndex<X> { + <span class="doccomment">/// Creates a new a `WeightedIndex` [`Distribution`] using the values + /// in `weights`. The weights can use any type `X` for which an + /// implementation of [`Uniform<X>`] exists. + /// + /// Returns an error if the iterator is empty, if any weight is `< 0`, or + /// if its total value is 0. + /// + /// [`Uniform<X>`]: crate::distributions::uniform::Uniform + </span><span class="kw">pub fn </span>new<I>(weights: I) -> <span class="prelude-ty">Result</span><WeightedIndex<X>, WeightedError> + <span class="kw">where + </span>I: IntoIterator, + I::Item: SampleBorrow<X>, + X: <span class="kw">for</span><<span class="lifetime">'a</span>> ::core::ops::AddAssign<<span class="kw-2">&</span><span class="lifetime">'a </span>X> + Clone + Default, + { + <span class="kw">let </span><span class="kw-2">mut </span>iter = weights.into_iter(); + <span class="kw">let </span><span class="kw-2">mut </span>total_weight: X = iter.next().ok_or(WeightedError::NoItem)<span class="question-mark">?</span>.borrow().clone(); + + <span class="kw">let </span>zero = <X <span class="kw">as </span>Default>::default(); + <span class="kw">if </span>!(total_weight >= zero) { + <span class="kw">return </span><span class="prelude-val">Err</span>(WeightedError::InvalidWeight); + } + + <span class="kw">let </span><span class="kw-2">mut </span>weights = Vec::<X>::with_capacity(iter.size_hint().<span class="number">0</span>); + <span class="kw">for </span>w <span class="kw">in </span>iter { + <span class="comment">// Note that `!(w >= x)` is not equivalent to `w < x` for partially + // ordered types due to NaNs which are equal to nothing. + </span><span class="kw">if </span>!(w.borrow() >= <span class="kw-2">&</span>zero) { + <span class="kw">return </span><span class="prelude-val">Err</span>(WeightedError::InvalidWeight); + } + weights.push(total_weight.clone()); + total_weight += w.borrow(); + } + + <span class="kw">if </span>total_weight == zero { + <span class="kw">return </span><span class="prelude-val">Err</span>(WeightedError::AllWeightsZero); + } + <span class="kw">let </span>distr = X::Sampler::new(zero, total_weight.clone()); + + <span class="prelude-val">Ok</span>(WeightedIndex { + cumulative_weights: weights, + total_weight, + weight_distribution: distr, + }) + } + + <span class="doccomment">/// Update a subset of weights, without changing the number of weights. + /// + /// `new_weights` must be sorted by the index. + /// + /// Using this method instead of `new` might be more efficient if only a small number of + /// weights is modified. No allocations are performed, unless the weight type `X` uses + /// allocation internally. + /// + /// In case of error, `self` is not modified. + </span><span class="kw">pub fn </span>update_weights(<span class="kw-2">&mut </span><span class="self">self</span>, new_weights: <span class="kw-2">&</span>[(usize, <span class="kw-2">&</span>X)]) -> <span class="prelude-ty">Result</span><(), WeightedError> + <span class="kw">where </span>X: <span class="kw">for</span><<span class="lifetime">'a</span>> ::core::ops::AddAssign<<span class="kw-2">&</span><span class="lifetime">'a </span>X> + + <span class="kw">for</span><<span class="lifetime">'a</span>> ::core::ops::SubAssign<<span class="kw-2">&</span><span class="lifetime">'a </span>X> + + Clone + + Default { + <span class="kw">if </span>new_weights.is_empty() { + <span class="kw">return </span><span class="prelude-val">Ok</span>(()); + } + + <span class="kw">let </span>zero = <X <span class="kw">as </span>Default>::default(); + + <span class="kw">let </span><span class="kw-2">mut </span>total_weight = <span class="self">self</span>.total_weight.clone(); + + <span class="comment">// Check for errors first, so we don't modify `self` in case something + // goes wrong. + </span><span class="kw">let </span><span class="kw-2">mut </span>prev_i = <span class="prelude-val">None</span>; + <span class="kw">for </span><span class="kw-2">&</span>(i, w) <span class="kw">in </span>new_weights { + <span class="kw">if let </span><span class="prelude-val">Some</span>(old_i) = prev_i { + <span class="kw">if </span>old_i >= i { + <span class="kw">return </span><span class="prelude-val">Err</span>(WeightedError::InvalidWeight); + } + } + <span class="kw">if </span>!(<span class="kw-2">*</span>w >= zero) { + <span class="kw">return </span><span class="prelude-val">Err</span>(WeightedError::InvalidWeight); + } + <span class="kw">if </span>i > <span class="self">self</span>.cumulative_weights.len() { + <span class="kw">return </span><span class="prelude-val">Err</span>(WeightedError::TooMany); + } + + <span class="kw">let </span><span class="kw-2">mut </span>old_w = <span class="kw">if </span>i < <span class="self">self</span>.cumulative_weights.len() { + <span class="self">self</span>.cumulative_weights[i].clone() + } <span class="kw">else </span>{ + <span class="self">self</span>.total_weight.clone() + }; + <span class="kw">if </span>i > <span class="number">0 </span>{ + old_w -= <span class="kw-2">&</span><span class="self">self</span>.cumulative_weights[i - <span class="number">1</span>]; + } + + total_weight -= <span class="kw-2">&</span>old_w; + total_weight += w; + prev_i = <span class="prelude-val">Some</span>(i); + } + <span class="kw">if </span>total_weight <= zero { + <span class="kw">return </span><span class="prelude-val">Err</span>(WeightedError::AllWeightsZero); + } + + <span class="comment">// Update the weights. Because we checked all the preconditions in the + // previous loop, this should never panic. + </span><span class="kw">let </span><span class="kw-2">mut </span>iter = new_weights.iter(); + + <span class="kw">let </span><span class="kw-2">mut </span>prev_weight = zero.clone(); + <span class="kw">let </span><span class="kw-2">mut </span>next_new_weight = iter.next(); + <span class="kw">let </span><span class="kw-2">&</span>(first_new_index, <span class="kw">_</span>) = next_new_weight.unwrap(); + <span class="kw">let </span><span class="kw-2">mut </span>cumulative_weight = <span class="kw">if </span>first_new_index > <span class="number">0 </span>{ + <span class="self">self</span>.cumulative_weights[first_new_index - <span class="number">1</span>].clone() + } <span class="kw">else </span>{ + zero.clone() + }; + <span class="kw">for </span>i <span class="kw">in </span>first_new_index..<span class="self">self</span>.cumulative_weights.len() { + <span class="kw">match </span>next_new_weight { + <span class="prelude-val">Some</span>(<span class="kw-2">&</span>(j, w)) <span class="kw">if </span>i == j => { + cumulative_weight += w; + next_new_weight = iter.next(); + } + <span class="kw">_ </span>=> { + <span class="kw">let </span><span class="kw-2">mut </span>tmp = <span class="self">self</span>.cumulative_weights[i].clone(); + tmp -= <span class="kw-2">&</span>prev_weight; <span class="comment">// We know this is positive. + </span>cumulative_weight += <span class="kw-2">&</span>tmp; + } + } + prev_weight = cumulative_weight.clone(); + core::mem::swap(<span class="kw-2">&mut </span>prev_weight, <span class="kw-2">&mut </span><span class="self">self</span>.cumulative_weights[i]); + } + + <span class="self">self</span>.total_weight = total_weight; + <span class="self">self</span>.weight_distribution = X::Sampler::new(zero, <span class="self">self</span>.total_weight.clone()); + + <span class="prelude-val">Ok</span>(()) + } +} + +<span class="kw">impl</span><X> Distribution<usize> <span class="kw">for </span>WeightedIndex<X> +<span class="kw">where </span>X: SampleUniform + PartialOrd +{ + <span class="kw">fn </span>sample<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> usize { + <span class="kw">use </span>::core::cmp::Ordering; + <span class="kw">let </span>chosen_weight = <span class="self">self</span>.weight_distribution.sample(rng); + <span class="comment">// Find the first item which has a weight *higher* than the chosen weight. + </span><span class="self">self</span>.cumulative_weights + .binary_search_by(|w| { + <span class="kw">if </span><span class="kw-2">*</span>w <= chosen_weight { + Ordering::Less + } <span class="kw">else </span>{ + Ordering::Greater + } + }) + .unwrap_err() + } +} + +<span class="attribute">#[cfg(test)] +</span><span class="kw">mod </span>test { + <span class="kw">use super</span>::<span class="kw-2">*</span>; + + <span class="attribute">#[cfg(feature = <span class="string">"serde1"</span>)] + #[test] + </span><span class="kw">fn </span>test_weightedindex_serde1() { + <span class="kw">let </span>weighted_index = WeightedIndex::new(<span class="kw-2">&</span>[<span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>, <span class="number">6</span>, <span class="number">7</span>, <span class="number">8</span>, <span class="number">9</span>, <span class="number">10</span>]).unwrap(); + + <span class="kw">let </span>ser_weighted_index = bincode::serialize(<span class="kw-2">&</span>weighted_index).unwrap(); + <span class="kw">let </span>de_weighted_index: WeightedIndex<i32> = + bincode::deserialize(<span class="kw-2">&</span>ser_weighted_index).unwrap(); + + <span class="macro">assert_eq!</span>( + de_weighted_index.cumulative_weights, + weighted_index.cumulative_weights + ); + <span class="macro">assert_eq!</span>(de_weighted_index.total_weight, weighted_index.total_weight); + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_accepting_nan(){ + <span class="macro">assert_eq!</span>( + WeightedIndex::new(<span class="kw-2">&</span>[core::f32::NAN, <span class="number">0.5</span>]).unwrap_err(), + WeightedError::InvalidWeight, + ); + <span class="macro">assert_eq!</span>( + WeightedIndex::new(<span class="kw-2">&</span>[core::f32::NAN]).unwrap_err(), + WeightedError::InvalidWeight, + ); + <span class="macro">assert_eq!</span>( + WeightedIndex::new(<span class="kw-2">&</span>[<span class="number">0.5</span>, core::f32::NAN]).unwrap_err(), + WeightedError::InvalidWeight, + ); + + <span class="macro">assert_eq!</span>( + WeightedIndex::new(<span class="kw-2">&</span>[<span class="number">0.5</span>, <span class="number">7.0</span>]) + .unwrap() + .update_weights(<span class="kw-2">&</span>[(<span class="number">0</span>, <span class="kw-2">&</span>core::f32::NAN)]) + .unwrap_err(), + WeightedError::InvalidWeight, + ) + } + + + <span class="attribute">#[test] + #[cfg_attr(miri, ignore)] </span><span class="comment">// Miri is too slow + </span><span class="kw">fn </span>test_weightedindex() { + <span class="kw">let </span><span class="kw-2">mut </span>r = <span class="kw">crate</span>::test::rng(<span class="number">700</span>); + <span class="kw">const </span>N_REPS: u32 = <span class="number">5000</span>; + <span class="kw">let </span>weights = [<span class="number">1u32</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">0</span>, <span class="number">5</span>, <span class="number">6</span>, <span class="number">7</span>, <span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>, <span class="number">6</span>, <span class="number">7</span>]; + <span class="kw">let </span>total_weight = weights.iter().sum::<u32>() <span class="kw">as </span>f32; + + <span class="kw">let </span>verify = |result: [i32; <span class="number">14</span>]| { + <span class="kw">for </span>(i, count) <span class="kw">in </span>result.iter().enumerate() { + <span class="kw">let </span>exp = (weights[i] * N_REPS) <span class="kw">as </span>f32 / total_weight; + <span class="kw">let </span><span class="kw-2">mut </span>err = (<span class="kw-2">*</span>count <span class="kw">as </span>f32 - exp).abs(); + <span class="kw">if </span>err != <span class="number">0.0 </span>{ + err /= exp; + } + <span class="macro">assert!</span>(err <= <span class="number">0.25</span>); + } + }; + + <span class="comment">// WeightedIndex from vec + </span><span class="kw">let </span><span class="kw-2">mut </span>chosen = [<span class="number">0i32</span>; <span class="number">14</span>]; + <span class="kw">let </span>distr = WeightedIndex::new(weights.to_vec()).unwrap(); + <span class="kw">for _ in </span><span class="number">0</span>..N_REPS { + chosen[distr.sample(<span class="kw-2">&mut </span>r)] += <span class="number">1</span>; + } + verify(chosen); + + <span class="comment">// WeightedIndex from slice + </span>chosen = [<span class="number">0i32</span>; <span class="number">14</span>]; + <span class="kw">let </span>distr = WeightedIndex::new(<span class="kw-2">&</span>weights[..]).unwrap(); + <span class="kw">for _ in </span><span class="number">0</span>..N_REPS { + chosen[distr.sample(<span class="kw-2">&mut </span>r)] += <span class="number">1</span>; + } + verify(chosen); + + <span class="comment">// WeightedIndex from iterator + </span>chosen = [<span class="number">0i32</span>; <span class="number">14</span>]; + <span class="kw">let </span>distr = WeightedIndex::new(weights.iter()).unwrap(); + <span class="kw">for _ in </span><span class="number">0</span>..N_REPS { + chosen[distr.sample(<span class="kw-2">&mut </span>r)] += <span class="number">1</span>; + } + verify(chosen); + + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">5 </span>{ + <span class="macro">assert_eq!</span>(WeightedIndex::new(<span class="kw-2">&</span>[<span class="number">0</span>, <span class="number">1</span>]).unwrap().sample(<span class="kw-2">&mut </span>r), <span class="number">1</span>); + <span class="macro">assert_eq!</span>(WeightedIndex::new(<span class="kw-2">&</span>[<span class="number">1</span>, <span class="number">0</span>]).unwrap().sample(<span class="kw-2">&mut </span>r), <span class="number">0</span>); + <span class="macro">assert_eq!</span>( + WeightedIndex::new(<span class="kw-2">&</span>[<span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">10</span>, <span class="number">0</span>]) + .unwrap() + .sample(<span class="kw-2">&mut </span>r), + <span class="number">4 + </span>); + } + + <span class="macro">assert_eq!</span>( + WeightedIndex::new(<span class="kw-2">&</span>[<span class="number">10</span>][<span class="number">0</span>..<span class="number">0</span>]).unwrap_err(), + WeightedError::NoItem + ); + <span class="macro">assert_eq!</span>( + WeightedIndex::new(<span class="kw-2">&</span>[<span class="number">0</span>]).unwrap_err(), + WeightedError::AllWeightsZero + ); + <span class="macro">assert_eq!</span>( + WeightedIndex::new(<span class="kw-2">&</span>[<span class="number">10</span>, <span class="number">20</span>, -<span class="number">1</span>, <span class="number">30</span>]).unwrap_err(), + WeightedError::InvalidWeight + ); + <span class="macro">assert_eq!</span>( + WeightedIndex::new(<span class="kw-2">&</span>[-<span class="number">10</span>, <span class="number">20</span>, <span class="number">1</span>, <span class="number">30</span>]).unwrap_err(), + WeightedError::InvalidWeight + ); + <span class="macro">assert_eq!</span>( + WeightedIndex::new(<span class="kw-2">&</span>[-<span class="number">10</span>]).unwrap_err(), + WeightedError::InvalidWeight + ); + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_update_weights() { + <span class="kw">let </span>data = [ + ( + <span class="kw-2">&</span>[<span class="number">10u32</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>][..], + <span class="kw-2">&</span>[(<span class="number">1</span>, <span class="kw-2">&</span><span class="number">100</span>), (<span class="number">2</span>, <span class="kw-2">&</span><span class="number">4</span>)][..], <span class="comment">// positive change + </span><span class="kw-2">&</span>[<span class="number">10</span>, <span class="number">100</span>, <span class="number">4</span>, <span class="number">4</span>][..], + ), + ( + <span class="kw-2">&</span>[<span class="number">1u32</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">0</span>, <span class="number">5</span>, <span class="number">6</span>, <span class="number">7</span>, <span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>, <span class="number">6</span>, <span class="number">7</span>][..], + <span class="kw-2">&</span>[(<span class="number">2</span>, <span class="kw-2">&</span><span class="number">1</span>), (<span class="number">5</span>, <span class="kw-2">&</span><span class="number">1</span>), (<span class="number">13</span>, <span class="kw-2">&</span><span class="number">100</span>)][..], <span class="comment">// negative change and last element + </span><span class="kw-2">&</span>[<span class="number">1u32</span>, <span class="number">2</span>, <span class="number">1</span>, <span class="number">0</span>, <span class="number">5</span>, <span class="number">1</span>, <span class="number">7</span>, <span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>, <span class="number">6</span>, <span class="number">100</span>][..], + ), + ]; + + <span class="kw">for </span>(weights, update, expected_weights) <span class="kw">in </span>data.iter() { + <span class="kw">let </span>total_weight = weights.iter().sum::<u32>(); + <span class="kw">let </span><span class="kw-2">mut </span>distr = WeightedIndex::new(weights.to_vec()).unwrap(); + <span class="macro">assert_eq!</span>(distr.total_weight, total_weight); + + distr.update_weights(update).unwrap(); + <span class="kw">let </span>expected_total_weight = expected_weights.iter().sum::<u32>(); + <span class="kw">let </span>expected_distr = WeightedIndex::new(expected_weights.to_vec()).unwrap(); + <span class="macro">assert_eq!</span>(distr.total_weight, expected_total_weight); + <span class="macro">assert_eq!</span>(distr.total_weight, expected_distr.total_weight); + <span class="macro">assert_eq!</span>(distr.cumulative_weights, expected_distr.cumulative_weights); + } + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>value_stability() { + <span class="kw">fn </span>test_samples<X: SampleUniform + PartialOrd, I>( + weights: I, buf: <span class="kw-2">&mut </span>[usize], expected: <span class="kw-2">&</span>[usize], + ) <span class="kw">where + </span>I: IntoIterator, + I::Item: SampleBorrow<X>, + X: <span class="kw">for</span><<span class="lifetime">'a</span>> ::core::ops::AddAssign<<span class="kw-2">&</span><span class="lifetime">'a </span>X> + Clone + Default, + { + <span class="macro">assert_eq!</span>(buf.len(), expected.len()); + <span class="kw">let </span>distr = WeightedIndex::new(weights).unwrap(); + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">701</span>); + <span class="kw">for </span>r <span class="kw">in </span>buf.iter_mut() { + <span class="kw-2">*</span>r = rng.sample(<span class="kw-2">&</span>distr); + } + <span class="macro">assert_eq!</span>(buf, expected); + } + + <span class="kw">let </span><span class="kw-2">mut </span>buf = [<span class="number">0</span>; <span class="number">10</span>]; + test_samples(<span class="kw-2">&</span>[<span class="number">1i32</span>, <span class="number">1</span>, <span class="number">1</span>, <span class="number">1</span>, <span class="number">1</span>, <span class="number">1</span>, <span class="number">1</span>, <span class="number">1</span>, <span class="number">1</span>], <span class="kw-2">&mut </span>buf, <span class="kw-2">&</span>[ + <span class="number">0</span>, <span class="number">6</span>, <span class="number">2</span>, <span class="number">6</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">7</span>, <span class="number">8</span>, <span class="number">2</span>, <span class="number">5</span>, + ]); + test_samples(<span class="kw-2">&</span>[<span class="number">0.7f32</span>, <span class="number">0.1</span>, <span class="number">0.1</span>, <span class="number">0.1</span>], <span class="kw-2">&mut </span>buf, <span class="kw-2">&</span>[ + <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">1</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">0</span>, <span class="number">0</span>, + ]); + test_samples(<span class="kw-2">&</span>[<span class="number">1.0f64</span>, <span class="number">0.999</span>, <span class="number">0.998</span>, <span class="number">0.997</span>], <span class="kw-2">&mut </span>buf, <span class="kw-2">&</span>[ + <span class="number">2</span>, <span class="number">2</span>, <span class="number">1</span>, <span class="number">3</span>, <span class="number">2</span>, <span class="number">1</span>, <span class="number">3</span>, <span class="number">3</span>, <span class="number">2</span>, <span class="number">1</span>, + ]); + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>weighted_index_distributions_can_be_compared() { + <span class="macro">assert_eq!</span>(WeightedIndex::new(<span class="kw-2">&</span>[<span class="number">1</span>, <span class="number">2</span>]), WeightedIndex::new(<span class="kw-2">&</span>[<span class="number">1</span>, <span class="number">2</span>])); + } +} + +<span class="doccomment">/// Error type returned from `WeightedIndex::new`. +</span><span class="attribute">#[cfg_attr(doc_cfg, doc(cfg(feature = <span class="string">"alloc"</span>)))] +#[derive(Debug, Clone, Copy, PartialEq, Eq)] +</span><span class="kw">pub enum </span>WeightedError { + <span class="doccomment">/// The provided weight collection contains no items. + </span>NoItem, + + <span class="doccomment">/// A weight is either less than zero, greater than the supported maximum, + /// NaN, or otherwise invalid. + </span>InvalidWeight, + + <span class="doccomment">/// All items in the provided weight collection are zero. + </span>AllWeightsZero, + + <span class="doccomment">/// Too many weights are provided (length greater than `u32::MAX`) + </span>TooMany, +} + +<span class="attribute">#[cfg(feature = <span class="string">"std"</span>)] +</span><span class="kw">impl </span>std::error::Error <span class="kw">for </span>WeightedError {} + +<span class="kw">impl </span>fmt::Display <span class="kw">for </span>WeightedError { + <span class="kw">fn </span>fmt(<span class="kw-2">&</span><span class="self">self</span>, f: <span class="kw-2">&mut </span>fmt::Formatter) -> fmt::Result { + f.write_str(<span class="kw">match </span><span class="kw-2">*</span><span class="self">self </span>{ + WeightedError::NoItem => <span class="string">"No weights provided in distribution"</span>, + WeightedError::InvalidWeight => <span class="string">"A weight is invalid in distribution"</span>, + WeightedError::AllWeightsZero => <span class="string">"All weights are zero in distribution"</span>, + WeightedError::TooMany => <span class="string">"Too many weights (hit u32::MAX) in distribution"</span>, + }) + } +} +</code></pre></div> +</section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="rand" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0 (69f9c33d7 2022-12-12) (Arch Linux rust 1:1.66.0-1)" ></div></body></html>
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This file may not be copied, modified, or distributed +// except according to those terms. + +</span><span class="doccomment">//! Utilities for random number generation +//! +//! Rand provides utilities to generate random numbers, to convert them to +//! useful types and distributions, and some randomness-related algorithms. +//! +//! # Quick Start +//! +//! To get you started quickly, the easiest and highest-level way to get +//! a random value is to use [`random()`]; alternatively you can use +//! [`thread_rng()`]. The [`Rng`] trait provides a useful API on all RNGs, while +//! the [`distributions`] and [`seq`] modules provide further +//! functionality on top of RNGs. +//! +//! ``` +//! use rand::prelude::*; +//! +//! if rand::random() { // generates a boolean +//! // Try printing a random unicode code point (probably a bad idea)! +//! println!("char: {}", rand::random::<char>()); +//! } +//! +//! let mut rng = rand::thread_rng(); +//! let y: f64 = rng.gen(); // generates a float between 0 and 1 +//! +//! let mut nums: Vec<i32> = (1..100).collect(); +//! nums.shuffle(&mut rng); +//! ``` +//! +//! # The Book +//! +//! For the user guide and further documentation, please read +//! [The Rust Rand Book](https://rust-random.github.io/book). + +</span><span class="attribute">#![doc( + html_logo_url = <span class="string">"https://www.rust-lang.org/logos/rust-logo-128x128-blk.png"</span>, + html_favicon_url = <span class="string">"https://www.rust-lang.org/favicon.ico"</span>, + html_root_url = <span class="string">"https://rust-random.github.io/rand/" +</span>)] +#![deny(missing_docs)] +#![deny(missing_debug_implementations)] +#![doc(test(attr(allow(unused_variables), deny(warnings))))] +#![no_std] +#![cfg_attr(feature = <span class="string">"simd_support"</span>, feature(stdsimd))] +#![cfg_attr(doc_cfg, feature(doc_cfg))] +#![allow( + clippy::float_cmp, + clippy::neg_cmp_op_on_partial_ord, +)] + +#[cfg(feature = <span class="string">"std"</span>)] </span><span class="kw">extern crate </span>std; +<span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] </span><span class="kw">extern crate </span>alloc; + +<span class="attribute">#[allow(unused)] +</span><span class="macro">macro_rules! </span>trace { ($(<span class="macro-nonterminal">$x</span>:tt)<span class="kw-2">*</span>) => ( + <span class="attribute">#[cfg(feature = <span class="string">"log"</span>)] </span>{ + <span class="macro">log::trace!</span>($(<span class="macro-nonterminal">$x</span>)<span class="kw-2">*</span>) + } +) } +<span class="attribute">#[allow(unused)] +</span><span class="macro">macro_rules! </span>debug { ($(<span class="macro-nonterminal">$x</span>:tt)<span class="kw-2">*</span>) => ( + <span class="attribute">#[cfg(feature = <span class="string">"log"</span>)] </span>{ + <span class="macro">log::debug!</span>($(<span class="macro-nonterminal">$x</span>)<span class="kw-2">*</span>) + } +) } +<span class="attribute">#[allow(unused)] +</span><span class="macro">macro_rules! </span>info { ($(<span class="macro-nonterminal">$x</span>:tt)<span class="kw-2">*</span>) => ( + <span class="attribute">#[cfg(feature = <span class="string">"log"</span>)] </span>{ + <span class="macro">log::info!</span>($(<span class="macro-nonterminal">$x</span>)<span class="kw-2">*</span>) + } +) } +<span class="attribute">#[allow(unused)] +</span><span class="macro">macro_rules! </span>warn { ($(<span class="macro-nonterminal">$x</span>:tt)<span class="kw-2">*</span>) => ( + <span class="attribute">#[cfg(feature = <span class="string">"log"</span>)] </span>{ + <span class="macro">log::warn!</span>($(<span class="macro-nonterminal">$x</span>)<span class="kw-2">*</span>) + } +) } +<span class="attribute">#[allow(unused)] +</span><span class="macro">macro_rules! </span>error { ($(<span class="macro-nonterminal">$x</span>:tt)<span class="kw-2">*</span>) => ( + <span class="attribute">#[cfg(feature = <span class="string">"log"</span>)] </span>{ + <span class="macro">log::error!</span>($(<span class="macro-nonterminal">$x</span>)<span class="kw-2">*</span>) + } +) } + +<span class="comment">// Re-exports from rand_core +</span><span class="kw">pub use </span>rand_core::{CryptoRng, Error, RngCore, SeedableRng}; + +<span class="comment">// Public modules +</span><span class="kw">pub mod </span>distributions; +<span class="kw">pub mod </span>prelude; +<span class="kw">mod </span>rng; +<span class="kw">pub mod </span>rngs; +<span class="kw">pub mod </span>seq; + +<span class="comment">// Public exports +</span><span class="attribute">#[cfg(all(feature = <span class="string">"std"</span>, feature = <span class="string">"std_rng"</span>))] +</span><span class="kw">pub use </span><span class="kw">crate</span>::rngs::thread::thread_rng; +<span class="kw">pub use </span>rng::{Fill, Rng}; + +<span class="attribute">#[cfg(all(feature = <span class="string">"std"</span>, feature = <span class="string">"std_rng"</span>))] +</span><span class="kw">use </span><span class="kw">crate</span>::distributions::{Distribution, Standard}; + +<span class="doccomment">/// Generates a random value using the thread-local random number generator. +/// +/// This is simply a shortcut for `thread_rng().gen()`. See [`thread_rng`] for +/// documentation of the entropy source and [`Standard`] for documentation of +/// distributions and type-specific generation. +/// +/// # Provided implementations +/// +/// The following types have provided implementations that +/// generate values with the following ranges and distributions: +/// +/// * Integers (`i32`, `u32`, `isize`, `usize`, etc.): Uniformly distributed +/// over all values of the type. +/// * `char`: Uniformly distributed over all Unicode scalar values, i.e. all +/// code points in the range `0...0x10_FFFF`, except for the range +/// `0xD800...0xDFFF` (the surrogate code points). This includes +/// unassigned/reserved code points. +/// * `bool`: Generates `false` or `true`, each with probability 0.5. +/// * Floating point types (`f32` and `f64`): Uniformly distributed in the +/// half-open range `[0, 1)`. See notes below. +/// * Wrapping integers (`Wrapping<T>`), besides the type identical to their +/// normal integer variants. +/// +/// Also supported is the generation of the following +/// compound types where all component types are supported: +/// +/// * Tuples (up to 12 elements): each element is generated sequentially. +/// * Arrays (up to 32 elements): each element is generated sequentially; +/// see also [`Rng::fill`] which supports arbitrary array length for integer +/// types and tends to be faster for `u32` and smaller types. +/// * `Option<T>` first generates a `bool`, and if true generates and returns +/// `Some(value)` where `value: T`, otherwise returning `None`. +/// +/// # Examples +/// +/// ``` +/// let x = rand::random::<u8>(); +/// println!("{}", x); +/// +/// let y = rand::random::<f64>(); +/// println!("{}", y); +/// +/// if rand::random() { // generates a boolean +/// println!("Better lucky than good!"); +/// } +/// ``` +/// +/// If you're calling `random()` in a loop, caching the generator as in the +/// following example can increase performance. +/// +/// ``` +/// use rand::Rng; +/// +/// let mut v = vec![1, 2, 3]; +/// +/// for x in v.iter_mut() { +/// *x = rand::random() +/// } +/// +/// // can be made faster by caching thread_rng +/// +/// let mut rng = rand::thread_rng(); +/// +/// for x in v.iter_mut() { +/// *x = rng.gen(); +/// } +/// ``` +/// +/// [`Standard`]: distributions::Standard +</span><span class="attribute">#[cfg(all(feature = <span class="string">"std"</span>, feature = <span class="string">"std_rng"</span>))] +#[cfg_attr(doc_cfg, doc(cfg(all(feature = <span class="string">"std"</span>, feature = <span class="string">"std_rng"</span>))))] +#[inline] +</span><span class="kw">pub fn </span>random<T>() -> T +<span class="kw">where </span>Standard: Distribution<T> { + thread_rng().gen() +} + +<span class="attribute">#[cfg(test)] +</span><span class="kw">mod </span>test { + <span class="kw">use super</span>::<span class="kw-2">*</span>; + + <span class="doccomment">/// Construct a deterministic RNG with the given seed + </span><span class="kw">pub fn </span>rng(seed: u64) -> <span class="kw">impl </span>RngCore { + <span class="comment">// For tests, we want a statistically good, fast, reproducible RNG. + // PCG32 will do fine, and will be easy to embed if we ever need to. + </span><span class="kw">const </span>INC: u64 = <span class="number">11634580027462260723</span>; + rand_pcg::Pcg32::new(seed, INC) + } + + <span class="attribute">#[test] + #[cfg(all(feature = <span class="string">"std"</span>, feature = <span class="string">"std_rng"</span>))] + </span><span class="kw">fn </span>test_random() { + <span class="kw">let </span>_n: usize = random(); + <span class="kw">let </span>_f: f32 = random(); + <span class="kw">let </span>_o: <span class="prelude-ty">Option</span><<span class="prelude-ty">Option</span><i8>> = random(); + <span class="attribute">#[allow(clippy::type_complexity)] + </span><span class="kw">let </span>_many: ( + (), + (usize, isize, <span class="prelude-ty">Option</span><(u32, (bool,))>), + (u8, i8, u16, i16, u32, i32, u64, i64), + (f32, (f64, (f64,))), + ) = random(); + } +} +</code></pre></div> +</section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="rand" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0 (69f9c33d7 2022-12-12) (Arch Linux rust 1:1.66.0-1)" ></div></body></html>
\ No newline at end of file diff --git a/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/prelude.rs.html b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/prelude.rs.html new file mode 100644 index 0000000..777b203 --- /dev/null +++ b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/prelude.rs.html @@ -0,0 +1,71 @@ +<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/home/pico/.local/share/cargo/registry/src/github.com-1ecc6299db9ec823/rand-0.8.5/src/prelude.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>prelude.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../normalize.css"><link rel="stylesheet" href="../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../ayu.css" disabled><link rel="stylesheet" href="../../dark.css" disabled><link rel="stylesheet" href="../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../storage.js"></script><script defer src="../../source-script.js"></script><script defer src="../../source-files.js"></script><script defer src="../../main.js"></script><noscript><link rel="stylesheet" href="../../noscript.css"></noscript><link rel="icon" href="https://www.rust-lang.org/favicon.ico"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../rand/index.html"> + <img src="https://www.rust-lang.org/logos/rust-logo-128x128-blk.png" alt="logo"></a><form class="search-form"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../wheel.svg"></a></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> +<span id="2">2</span> +<span id="3">3</span> +<span id="4">4</span> +<span id="5">5</span> +<span id="6">6</span> +<span id="7">7</span> +<span id="8">8</span> +<span id="9">9</span> +<span id="10">10</span> +<span id="11">11</span> +<span id="12">12</span> +<span id="13">13</span> +<span id="14">14</span> +<span id="15">15</span> +<span id="16">16</span> +<span id="17">17</span> +<span id="18">18</span> +<span id="19">19</span> +<span id="20">20</span> +<span id="21">21</span> +<span id="22">22</span> +<span id="23">23</span> +<span id="24">24</span> +<span id="25">25</span> +<span id="26">26</span> +<span id="27">27</span> +<span id="28">28</span> +<span id="29">29</span> +<span id="30">30</span> +<span id="31">31</span> +<span id="32">32</span> +<span id="33">33</span> +<span id="34">34</span> +</pre><pre class="rust"><code><span class="comment">// Copyright 2018 Developers of the Rand project. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +</span><span class="doccomment">//! Convenience re-export of common members +//! +//! Like the standard library's prelude, this module simplifies importing of +//! common items. Unlike the standard prelude, the contents of this module must +//! be imported manually: +//! +//! ``` +//! use rand::prelude::*; +//! # let mut r = StdRng::from_rng(thread_rng()).unwrap(); +//! # let _: f32 = r.gen(); +//! ``` + +</span><span class="attribute">#[doc(no_inline)] </span><span class="kw">pub use </span><span class="kw">crate</span>::distributions::Distribution; +<span class="attribute">#[cfg(feature = <span class="string">"small_rng"</span>)] +#[doc(no_inline)] +</span><span class="kw">pub use </span><span class="kw">crate</span>::rngs::SmallRng; +<span class="attribute">#[cfg(feature = <span class="string">"std_rng"</span>)] +#[doc(no_inline)] </span><span class="kw">pub use </span><span class="kw">crate</span>::rngs::StdRng; +<span class="attribute">#[doc(no_inline)] +#[cfg(all(feature = <span class="string">"std"</span>, feature = <span class="string">"std_rng"</span>))] +</span><span class="kw">pub use </span><span class="kw">crate</span>::rngs::ThreadRng; +<span class="attribute">#[doc(no_inline)] </span><span class="kw">pub use </span><span class="kw">crate</span>::seq::{IteratorRandom, SliceRandom}; +<span class="attribute">#[doc(no_inline)] +#[cfg(all(feature = <span class="string">"std"</span>, feature = <span class="string">"std_rng"</span>))] +</span><span class="kw">pub use crate</span>::{random, thread_rng}; +<span class="attribute">#[doc(no_inline)] </span><span class="kw">pub use crate</span>::{CryptoRng, Rng, RngCore, SeedableRng}; +</code></pre></div> +</section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="rand" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0 (69f9c33d7 2022-12-12) (Arch Linux rust 1:1.66.0-1)" ></div></body></html>
\ No newline at end of file diff --git a/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/rng.rs.html b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/rng.rs.html new file mode 100644 index 0000000..1e28705 --- /dev/null +++ b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/rng.rs.html @@ -0,0 +1,1203 @@ +<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/home/pico/.local/share/cargo/registry/src/github.com-1ecc6299db9ec823/rand-0.8.5/src/rng.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>rng.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Regular.woff2"><link 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href="https://www.rust-lang.org/favicon.ico"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../rand/index.html"> + <img src="https://www.rust-lang.org/logos/rust-logo-128x128-blk.png" alt="logo"></a><form class="search-form"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../wheel.svg"></a></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre 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id="599">599</span> +<span id="600">600</span> +</pre><pre class="rust"><code><span class="comment">// Copyright 2018 Developers of the Rand project. +// Copyright 2013-2017 The Rust Project Developers. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +</span><span class="doccomment">//! [`Rng`] trait + +</span><span class="kw">use </span>rand_core::{Error, RngCore}; +<span class="kw">use </span><span class="kw">crate</span>::distributions::uniform::{SampleRange, SampleUniform}; +<span class="kw">use </span><span class="kw">crate</span>::distributions::{<span class="self">self</span>, Distribution, Standard}; +<span class="kw">use </span>core::num::Wrapping; +<span class="kw">use </span>core::{mem, slice}; + +<span class="doccomment">/// An automatically-implemented extension trait on [`RngCore`] providing high-level +/// generic methods for sampling values and other convenience methods. +/// +/// This is the primary trait to use when generating random values. +/// +/// # Generic usage +/// +/// The basic pattern is `fn foo<R: Rng + ?Sized>(rng: &mut R)`. Some +/// things are worth noting here: +/// +/// - Since `Rng: RngCore` and every `RngCore` implements `Rng`, it makes no +/// difference whether we use `R: Rng` or `R: RngCore`. +/// - The `+ ?Sized` un-bounding allows functions to be called directly on +/// type-erased references; i.e. `foo(r)` where `r: &mut dyn RngCore`. Without +/// this it would be necessary to write `foo(&mut r)`. +/// +/// An alternative pattern is possible: `fn foo<R: Rng>(rng: R)`. This has some +/// trade-offs. It allows the argument to be consumed directly without a `&mut` +/// (which is how `from_rng(thread_rng())` works); also it still works directly +/// on references (including type-erased references). Unfortunately within the +/// function `foo` it is not known whether `rng` is a reference type or not, +/// hence many uses of `rng` require an extra reference, either explicitly +/// (`distr.sample(&mut rng)`) or implicitly (`rng.gen()`); one may hope the +/// optimiser can remove redundant references later. +/// +/// Example: +/// +/// ``` +/// # use rand::thread_rng; +/// use rand::Rng; +/// +/// fn foo<R: Rng + ?Sized>(rng: &mut R) -> f32 { +/// rng.gen() +/// } +/// +/// # let v = foo(&mut thread_rng()); +/// ``` +</span><span class="kw">pub trait </span>Rng: RngCore { + <span class="doccomment">/// Return a random value supporting the [`Standard`] distribution. + /// + /// # Example + /// + /// ``` + /// use rand::{thread_rng, Rng}; + /// + /// let mut rng = thread_rng(); + /// let x: u32 = rng.gen(); + /// println!("{}", x); + /// println!("{:?}", rng.gen::<(f64, bool)>()); + /// ``` + /// + /// # Arrays and tuples + /// + /// The `rng.gen()` method is able to generate arrays (up to 32 elements) + /// and tuples (up to 12 elements), so long as all element types can be + /// generated. + /// When using `rustc` ≥ 1.51, enable the `min_const_gen` feature to support + /// arrays larger than 32 elements. + /// + /// For arrays of integers, especially for those with small element types + /// (< 64 bit), it will likely be faster to instead use [`Rng::fill`]. + /// + /// ``` + /// use rand::{thread_rng, Rng}; + /// + /// let mut rng = thread_rng(); + /// let tuple: (u8, i32, char) = rng.gen(); // arbitrary tuple support + /// + /// let arr1: [f32; 32] = rng.gen(); // array construction + /// let mut arr2 = [0u8; 128]; + /// rng.fill(&mut arr2); // array fill + /// ``` + /// + /// [`Standard`]: distributions::Standard + </span><span class="attribute">#[inline] + </span><span class="kw">fn </span>gen<T>(<span class="kw-2">&mut </span><span class="self">self</span>) -> T + <span class="kw">where </span>Standard: Distribution<T> { + Standard.sample(<span class="self">self</span>) + } + + <span class="doccomment">/// Generate a random value in the given range. + /// + /// This function is optimised for the case that only a single sample is + /// made from the given range. See also the [`Uniform`] distribution + /// type which may be faster if sampling from the same range repeatedly. + /// + /// Only `gen_range(low..high)` and `gen_range(low..=high)` are supported. + /// + /// # Panics + /// + /// Panics if the range is empty. + /// + /// # Example + /// + /// ``` + /// use rand::{thread_rng, Rng}; + /// + /// let mut rng = thread_rng(); + /// + /// // Exclusive range + /// let n: u32 = rng.gen_range(0..10); + /// println!("{}", n); + /// let m: f64 = rng.gen_range(-40.0..1.3e5); + /// println!("{}", m); + /// + /// // Inclusive range + /// let n: u32 = rng.gen_range(0..=10); + /// println!("{}", n); + /// ``` + /// + /// [`Uniform`]: distributions::uniform::Uniform + </span><span class="kw">fn </span>gen_range<T, R>(<span class="kw-2">&mut </span><span class="self">self</span>, range: R) -> T + <span class="kw">where + </span>T: SampleUniform, + R: SampleRange<T> + { + <span class="macro">assert!</span>(!range.is_empty(), <span class="string">"cannot sample empty range"</span>); + range.sample_single(<span class="self">self</span>) + } + + <span class="doccomment">/// Sample a new value, using the given distribution. + /// + /// ### Example + /// + /// ``` + /// use rand::{thread_rng, Rng}; + /// use rand::distributions::Uniform; + /// + /// let mut rng = thread_rng(); + /// let x = rng.sample(Uniform::new(10u32, 15)); + /// // Type annotation requires two types, the type and distribution; the + /// // distribution can be inferred. + /// let y = rng.sample::<u16, _>(Uniform::new(10, 15)); + /// ``` + </span><span class="kw">fn </span>sample<T, D: Distribution<T>>(<span class="kw-2">&mut </span><span class="self">self</span>, distr: D) -> T { + distr.sample(<span class="self">self</span>) + } + + <span class="doccomment">/// Create an iterator that generates values using the given distribution. + /// + /// Note that this function takes its arguments by value. This works since + /// `(&mut R): Rng where R: Rng` and + /// `(&D): Distribution where D: Distribution`, + /// however borrowing is not automatic hence `rng.sample_iter(...)` may + /// need to be replaced with `(&mut rng).sample_iter(...)`. + /// + /// # Example + /// + /// ``` + /// use rand::{thread_rng, Rng}; + /// use rand::distributions::{Alphanumeric, Uniform, Standard}; + /// + /// let mut rng = thread_rng(); + /// + /// // Vec of 16 x f32: + /// let v: Vec<f32> = (&mut rng).sample_iter(Standard).take(16).collect(); + /// + /// // String: + /// let s: String = (&mut rng).sample_iter(Alphanumeric) + /// .take(7) + /// .map(char::from) + /// .collect(); + /// + /// // Combined values + /// println!("{:?}", (&mut rng).sample_iter(Standard).take(5) + /// .collect::<Vec<(f64, bool)>>()); + /// + /// // Dice-rolling: + /// let die_range = Uniform::new_inclusive(1, 6); + /// let mut roll_die = (&mut rng).sample_iter(die_range); + /// while roll_die.next().unwrap() != 6 { + /// println!("Not a 6; rolling again!"); + /// } + /// ``` + </span><span class="kw">fn </span>sample_iter<T, D>(<span class="self">self</span>, distr: D) -> distributions::DistIter<D, <span class="self">Self</span>, T> + <span class="kw">where + </span>D: Distribution<T>, + <span class="self">Self</span>: Sized, + { + distr.sample_iter(<span class="self">self</span>) + } + + <span class="doccomment">/// Fill any type implementing [`Fill`] with random data + /// + /// The distribution is expected to be uniform with portable results, but + /// this cannot be guaranteed for third-party implementations. + /// + /// This is identical to [`try_fill`] except that it panics on error. + /// + /// # Example + /// + /// ``` + /// use rand::{thread_rng, Rng}; + /// + /// let mut arr = [0i8; 20]; + /// thread_rng().fill(&mut arr[..]); + /// ``` + /// + /// [`fill_bytes`]: RngCore::fill_bytes + /// [`try_fill`]: Rng::try_fill + </span><span class="kw">fn </span>fill<T: Fill + <span class="question-mark">?</span>Sized>(<span class="kw-2">&mut </span><span class="self">self</span>, dest: <span class="kw-2">&mut </span>T) { + dest.try_fill(<span class="self">self</span>).unwrap_or_else(|<span class="kw">_</span>| <span class="macro">panic!</span>(<span class="string">"Rng::fill failed"</span>)) + } + + <span class="doccomment">/// Fill any type implementing [`Fill`] with random data + /// + /// The distribution is expected to be uniform with portable results, but + /// this cannot be guaranteed for third-party implementations. + /// + /// This is identical to [`fill`] except that it forwards errors. + /// + /// # Example + /// + /// ``` + /// # use rand::Error; + /// use rand::{thread_rng, Rng}; + /// + /// # fn try_inner() -> Result<(), Error> { + /// let mut arr = [0u64; 4]; + /// thread_rng().try_fill(&mut arr[..])?; + /// # Ok(()) + /// # } + /// + /// # try_inner().unwrap() + /// ``` + /// + /// [`try_fill_bytes`]: RngCore::try_fill_bytes + /// [`fill`]: Rng::fill + </span><span class="kw">fn </span>try_fill<T: Fill + <span class="question-mark">?</span>Sized>(<span class="kw-2">&mut </span><span class="self">self</span>, dest: <span class="kw-2">&mut </span>T) -> <span class="prelude-ty">Result</span><(), Error> { + dest.try_fill(<span class="self">self</span>) + } + + <span class="doccomment">/// Return a bool with a probability `p` of being true. + /// + /// See also the [`Bernoulli`] distribution, which may be faster if + /// sampling from the same probability repeatedly. + /// + /// # Example + /// + /// ``` + /// use rand::{thread_rng, Rng}; + /// + /// let mut rng = thread_rng(); + /// println!("{}", rng.gen_bool(1.0 / 3.0)); + /// ``` + /// + /// # Panics + /// + /// If `p < 0` or `p > 1`. + /// + /// [`Bernoulli`]: distributions::Bernoulli + </span><span class="attribute">#[inline] + </span><span class="kw">fn </span>gen_bool(<span class="kw-2">&mut </span><span class="self">self</span>, p: f64) -> bool { + <span class="kw">let </span>d = distributions::Bernoulli::new(p).unwrap(); + <span class="self">self</span>.sample(d) + } + + <span class="doccomment">/// Return a bool with a probability of `numerator/denominator` of being + /// true. I.e. `gen_ratio(2, 3)` has chance of 2 in 3, or about 67%, of + /// returning true. If `numerator == denominator`, then the returned value + /// is guaranteed to be `true`. If `numerator == 0`, then the returned + /// value is guaranteed to be `false`. + /// + /// See also the [`Bernoulli`] distribution, which may be faster if + /// sampling from the same `numerator` and `denominator` repeatedly. + /// + /// # Panics + /// + /// If `denominator == 0` or `numerator > denominator`. + /// + /// # Example + /// + /// ``` + /// use rand::{thread_rng, Rng}; + /// + /// let mut rng = thread_rng(); + /// println!("{}", rng.gen_ratio(2, 3)); + /// ``` + /// + /// [`Bernoulli`]: distributions::Bernoulli + </span><span class="attribute">#[inline] + </span><span class="kw">fn </span>gen_ratio(<span class="kw-2">&mut </span><span class="self">self</span>, numerator: u32, denominator: u32) -> bool { + <span class="kw">let </span>d = distributions::Bernoulli::from_ratio(numerator, denominator).unwrap(); + <span class="self">self</span>.sample(d) + } +} + +<span class="kw">impl</span><R: RngCore + <span class="question-mark">?</span>Sized> Rng <span class="kw">for </span>R {} + +<span class="doccomment">/// Types which may be filled with random data +/// +/// This trait allows arrays to be efficiently filled with random data. +/// +/// Implementations are expected to be portable across machines unless +/// clearly documented otherwise (see the +/// [Chapter on Portability](https://rust-random.github.io/book/portability.html)). +</span><span class="kw">pub trait </span>Fill { + <span class="doccomment">/// Fill self with random data + </span><span class="kw">fn </span>try_fill<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&mut </span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="prelude-ty">Result</span><(), Error>; +} + +<span class="macro">macro_rules! </span>impl_fill_each { + () => {}; + (<span class="macro-nonterminal">$t</span>:ty) => { + <span class="kw">impl </span>Fill <span class="kw">for </span>[<span class="macro-nonterminal">$t</span>] { + <span class="kw">fn </span>try_fill<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&mut </span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="prelude-ty">Result</span><(), Error> { + <span class="kw">for </span>elt <span class="kw">in </span><span class="self">self</span>.iter_mut() { + <span class="kw-2">*</span>elt = rng.gen(); + } + <span class="prelude-val">Ok</span>(()) + } + } + }; + (<span class="macro-nonterminal">$t</span>:ty, $(<span class="macro-nonterminal">$tt</span>:ty,)<span class="kw-2">*</span>) => { + <span class="macro">impl_fill_each!</span>(<span class="macro-nonterminal">$t</span>); + <span class="macro">impl_fill_each!</span>($(<span class="macro-nonterminal">$tt</span>,)<span class="kw-2">*</span>); + }; +} + +<span class="macro">impl_fill_each!</span>(bool, char, f32, f64,); + +<span class="kw">impl </span>Fill <span class="kw">for </span>[u8] { + <span class="kw">fn </span>try_fill<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&mut </span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="prelude-ty">Result</span><(), Error> { + rng.try_fill_bytes(<span class="self">self</span>) + } +} + +<span class="macro">macro_rules! </span>impl_fill { + () => {}; + (<span class="macro-nonterminal">$t</span>:ty) => { + <span class="kw">impl </span>Fill <span class="kw">for </span>[<span class="macro-nonterminal">$t</span>] { + <span class="attribute">#[inline(never)] </span><span class="comment">// in micro benchmarks, this improves performance + </span><span class="kw">fn </span>try_fill<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&mut </span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="prelude-ty">Result</span><(), Error> { + <span class="kw">if </span><span class="self">self</span>.len() > <span class="number">0 </span>{ + rng.try_fill_bytes(<span class="kw">unsafe </span>{ + slice::from_raw_parts_mut(<span class="self">self</span>.as_mut_ptr() + <span class="kw">as </span><span class="kw-2">*mut </span>u8, + <span class="self">self</span>.len() * mem::size_of::<<span class="macro-nonterminal">$t</span>>() + ) + })<span class="question-mark">?</span>; + <span class="kw">for </span>x <span class="kw">in </span><span class="self">self </span>{ + <span class="kw-2">*</span>x = x.to_le(); + } + } + <span class="prelude-val">Ok</span>(()) + } + } + + <span class="kw">impl </span>Fill <span class="kw">for </span>[Wrapping<<span class="macro-nonterminal">$t</span>>] { + <span class="attribute">#[inline(never)] + </span><span class="kw">fn </span>try_fill<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&mut </span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="prelude-ty">Result</span><(), Error> { + <span class="kw">if </span><span class="self">self</span>.len() > <span class="number">0 </span>{ + rng.try_fill_bytes(<span class="kw">unsafe </span>{ + slice::from_raw_parts_mut(<span class="self">self</span>.as_mut_ptr() + <span class="kw">as </span><span class="kw-2">*mut </span>u8, + <span class="self">self</span>.len() * mem::size_of::<<span class="macro-nonterminal">$t</span>>() + ) + })<span class="question-mark">?</span>; + <span class="kw">for </span>x <span class="kw">in </span><span class="self">self </span>{ + <span class="kw-2">*</span>x = Wrapping(x.<span class="number">0</span>.to_le()); + } + } + <span class="prelude-val">Ok</span>(()) + } + } + }; + (<span class="macro-nonterminal">$t</span>:ty, $(<span class="macro-nonterminal">$tt</span>:ty,)<span class="kw-2">*</span>) => { + <span class="macro">impl_fill!</span>(<span class="macro-nonterminal">$t</span>); + <span class="comment">// TODO: this could replace above impl once Rust #32463 is fixed + // impl_fill!(Wrapping<$t>); + </span><span class="macro">impl_fill!</span>($(<span class="macro-nonterminal">$tt</span>,)<span class="kw-2">*</span>); + } +} + +<span class="macro">impl_fill!</span>(u16, u32, u64, usize, u128,); +<span class="macro">impl_fill!</span>(i8, i16, i32, i64, isize, i128,); + +<span class="attribute">#[cfg_attr(doc_cfg, doc(cfg(feature = <span class="string">"min_const_gen"</span>)))] +#[cfg(feature = <span class="string">"min_const_gen"</span>)] +</span><span class="kw">impl</span><T, <span class="kw">const </span>N: usize> Fill <span class="kw">for </span>[T; N] +<span class="kw">where </span>[T]: Fill +{ + <span class="kw">fn </span>try_fill<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&mut </span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="prelude-ty">Result</span><(), Error> { + <span class="self">self</span>[..].try_fill(rng) + } +} + +<span class="attribute">#[cfg(not(feature = <span class="string">"min_const_gen"</span>))] +</span><span class="macro">macro_rules! </span>impl_fill_arrays { + (<span class="macro-nonterminal">$n</span>:expr,) => {}; + (<span class="macro-nonterminal">$n</span>:expr, <span class="macro-nonterminal">$N</span>:ident) => { + <span class="kw">impl</span><T> Fill <span class="kw">for </span>[T; <span class="macro-nonterminal">$n</span>] <span class="kw">where </span>[T]: Fill { + <span class="kw">fn </span>try_fill<R: Rng + <span class="question-mark">?</span>Sized>(<span class="kw-2">&mut </span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="prelude-ty">Result</span><(), Error> { + <span class="self">self</span>[..].try_fill(rng) + } + } + }; + (<span class="macro-nonterminal">$n</span>:expr, <span class="macro-nonterminal">$N</span>:ident, $(<span class="macro-nonterminal">$NN</span>:ident,)<span class="kw-2">*</span>) => { + <span class="macro">impl_fill_arrays!</span>(<span class="macro-nonterminal">$n</span>, <span class="macro-nonterminal">$N</span>); + <span class="macro">impl_fill_arrays!</span>(<span class="macro-nonterminal">$n </span>- <span class="number">1</span>, $(<span class="macro-nonterminal">$NN</span>,)<span class="kw-2">*</span>); + }; + (!div <span class="macro-nonterminal">$n</span>:expr,) => {}; + (!div <span class="macro-nonterminal">$n</span>:expr, <span class="macro-nonterminal">$N</span>:ident, $(<span class="macro-nonterminal">$NN</span>:ident,)<span class="kw-2">*</span>) => { + <span class="macro">impl_fill_arrays!</span>(<span class="macro-nonterminal">$n</span>, <span class="macro-nonterminal">$N</span>); + <span class="macro">impl_fill_arrays!</span>(!div <span class="macro-nonterminal">$n </span>/ <span class="number">2</span>, $(<span class="macro-nonterminal">$NN</span>,)<span class="kw-2">*</span>); + }; +} +<span class="attribute">#[cfg(not(feature = <span class="string">"min_const_gen"</span>))] +#[rustfmt::skip] +</span><span class="macro">impl_fill_arrays!</span>(<span class="number">32</span>, N,N,N,N,N,N,N,N,N,N,N,N,N,N,N,N,N,N,N,N,N,N,N,N,N,N,N,N,N,N,N,N,N,); +<span class="attribute">#[cfg(not(feature = <span class="string">"min_const_gen"</span>))] +</span><span class="macro">impl_fill_arrays!</span>(!div <span class="number">4096</span>, N,N,N,N,N,N,N,); + +<span class="attribute">#[cfg(test)] +</span><span class="kw">mod </span>test { + <span class="kw">use super</span>::<span class="kw-2">*</span>; + <span class="kw">use </span><span class="kw">crate</span>::test::rng; + <span class="kw">use </span><span class="kw">crate</span>::rngs::mock::StepRng; + <span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] </span><span class="kw">use </span>alloc::boxed::Box; + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_fill_bytes_default() { + <span class="kw">let </span><span class="kw-2">mut </span>r = StepRng::new(<span class="number">0x11_22_33_44_55_66_77_88</span>, <span class="number">0</span>); + + <span class="comment">// check every remainder mod 8, both in small and big vectors. + </span><span class="kw">let </span>lengths = [<span class="number">0</span>, <span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>, <span class="number">6</span>, <span class="number">7</span>, <span class="number">80</span>, <span class="number">81</span>, <span class="number">82</span>, <span class="number">83</span>, <span class="number">84</span>, <span class="number">85</span>, <span class="number">86</span>, <span class="number">87</span>]; + <span class="kw">for </span><span class="kw-2">&</span>n <span class="kw">in </span>lengths.iter() { + <span class="kw">let </span><span class="kw-2">mut </span>buffer = [<span class="number">0u8</span>; <span class="number">87</span>]; + <span class="kw">let </span>v = <span class="kw-2">&mut </span>buffer[<span class="number">0</span>..n]; + r.fill_bytes(v); + + <span class="comment">// use this to get nicer error messages. + </span><span class="kw">for </span>(i, <span class="kw-2">&</span>byte) <span class="kw">in </span>v.iter().enumerate() { + <span class="kw">if </span>byte == <span class="number">0 </span>{ + <span class="macro">panic!</span>(<span class="string">"byte {} of {} is zero"</span>, i, n) + } + } + } + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_fill() { + <span class="kw">let </span>x = <span class="number">9041086907909331047</span>; <span class="comment">// a random u64 + </span><span class="kw">let </span><span class="kw-2">mut </span>rng = StepRng::new(x, <span class="number">0</span>); + + <span class="comment">// Convert to byte sequence and back to u64; byte-swap twice if BE. + </span><span class="kw">let </span><span class="kw-2">mut </span>array = [<span class="number">0u64</span>; <span class="number">2</span>]; + rng.fill(<span class="kw-2">&mut </span>array[..]); + <span class="macro">assert_eq!</span>(array, [x, x]); + <span class="macro">assert_eq!</span>(rng.next_u64(), x); + + <span class="comment">// Convert to bytes then u32 in LE order + </span><span class="kw">let </span><span class="kw-2">mut </span>array = [<span class="number">0u32</span>; <span class="number">2</span>]; + rng.fill(<span class="kw-2">&mut </span>array[..]); + <span class="macro">assert_eq!</span>(array, [x <span class="kw">as </span>u32, (x >> <span class="number">32</span>) <span class="kw">as </span>u32]); + <span class="macro">assert_eq!</span>(rng.next_u32(), x <span class="kw">as </span>u32); + + <span class="comment">// Check equivalence using wrapped arrays + </span><span class="kw">let </span><span class="kw-2">mut </span>warray = [Wrapping(<span class="number">0u32</span>); <span class="number">2</span>]; + rng.fill(<span class="kw-2">&mut </span>warray[..]); + <span class="macro">assert_eq!</span>(array[<span class="number">0</span>], warray[<span class="number">0</span>].<span class="number">0</span>); + <span class="macro">assert_eq!</span>(array[<span class="number">1</span>], warray[<span class="number">1</span>].<span class="number">0</span>); + + <span class="comment">// Check equivalence for generated floats + </span><span class="kw">let </span><span class="kw-2">mut </span>array = [<span class="number">0f32</span>; <span class="number">2</span>]; + rng.fill(<span class="kw-2">&mut </span>array); + <span class="kw">let </span>gen: [f32; <span class="number">2</span>] = rng.gen(); + <span class="macro">assert_eq!</span>(array, gen); + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_fill_empty() { + <span class="kw">let </span><span class="kw-2">mut </span>array = [<span class="number">0u32</span>; <span class="number">0</span>]; + <span class="kw">let </span><span class="kw-2">mut </span>rng = StepRng::new(<span class="number">0</span>, <span class="number">1</span>); + rng.fill(<span class="kw-2">&mut </span>array); + rng.fill(<span class="kw-2">&mut </span>array[..]); + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_gen_range_int() { + <span class="kw">let </span><span class="kw-2">mut </span>r = rng(<span class="number">101</span>); + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">1000 </span>{ + <span class="kw">let </span>a = r.gen_range(-<span class="number">4711</span>..<span class="number">17</span>); + <span class="macro">assert!</span>((-<span class="number">4711</span>..<span class="number">17</span>).contains(<span class="kw-2">&</span>a)); + <span class="kw">let </span>a: i8 = r.gen_range(-<span class="number">3</span>..<span class="number">42</span>); + <span class="macro">assert!</span>((-<span class="number">3</span>..<span class="number">42</span>).contains(<span class="kw-2">&</span>a)); + <span class="kw">let </span>a: u16 = r.gen_range(<span class="number">10</span>..<span class="number">99</span>); + <span class="macro">assert!</span>((<span class="number">10</span>..<span class="number">99</span>).contains(<span class="kw-2">&</span>a)); + <span class="kw">let </span>a: i32 = r.gen_range(-<span class="number">100</span>..<span class="number">2000</span>); + <span class="macro">assert!</span>((-<span class="number">100</span>..<span class="number">2000</span>).contains(<span class="kw-2">&</span>a)); + <span class="kw">let </span>a: u32 = r.gen_range(<span class="number">12</span>..=<span class="number">24</span>); + <span class="macro">assert!</span>((<span class="number">12</span>..=<span class="number">24</span>).contains(<span class="kw-2">&</span>a)); + + <span class="macro">assert_eq!</span>(r.gen_range(<span class="number">0u32</span>..<span class="number">1</span>), <span class="number">0u32</span>); + <span class="macro">assert_eq!</span>(r.gen_range(-<span class="number">12i64</span>..-<span class="number">11</span>), -<span class="number">12i64</span>); + <span class="macro">assert_eq!</span>(r.gen_range(<span class="number">3_000_000</span>..<span class="number">3_000_001</span>), <span class="number">3_000_000</span>); + } + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_gen_range_float() { + <span class="kw">let </span><span class="kw-2">mut </span>r = rng(<span class="number">101</span>); + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">1000 </span>{ + <span class="kw">let </span>a = r.gen_range(-<span class="number">4.5</span>..<span class="number">1.7</span>); + <span class="macro">assert!</span>((-<span class="number">4.5</span>..<span class="number">1.7</span>).contains(<span class="kw-2">&</span>a)); + <span class="kw">let </span>a = r.gen_range(-<span class="number">1.1</span>..=-<span class="number">0.3</span>); + <span class="macro">assert!</span>((-<span class="number">1.1</span>..=-<span class="number">0.3</span>).contains(<span class="kw-2">&</span>a)); + + <span class="macro">assert_eq!</span>(r.gen_range(<span class="number">0.0f32</span>..=<span class="number">0.0</span>), <span class="number">0.</span>); + <span class="macro">assert_eq!</span>(r.gen_range(-<span class="number">11.0</span>..=-<span class="number">11.0</span>), -<span class="number">11.</span>); + <span class="macro">assert_eq!</span>(r.gen_range(<span class="number">3_000_000.0</span>..=<span class="number">3_000_000.0</span>), <span class="number">3_000_000.</span>); + } + } + + <span class="attribute">#[test] + #[should_panic] + </span><span class="kw">fn </span>test_gen_range_panic_int() { + <span class="attribute">#![allow(clippy::reversed_empty_ranges)] + </span><span class="kw">let </span><span class="kw-2">mut </span>r = rng(<span class="number">102</span>); + r.gen_range(<span class="number">5</span>..-<span class="number">2</span>); + } + + <span class="attribute">#[test] + #[should_panic] + </span><span class="kw">fn </span>test_gen_range_panic_usize() { + <span class="attribute">#![allow(clippy::reversed_empty_ranges)] + </span><span class="kw">let </span><span class="kw-2">mut </span>r = rng(<span class="number">103</span>); + r.gen_range(<span class="number">5</span>..<span class="number">2</span>); + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_gen_bool() { + <span class="attribute">#![allow(clippy::bool_assert_comparison)] + + </span><span class="kw">let </span><span class="kw-2">mut </span>r = rng(<span class="number">105</span>); + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">5 </span>{ + <span class="macro">assert_eq!</span>(r.gen_bool(<span class="number">0.0</span>), <span class="bool-val">false</span>); + <span class="macro">assert_eq!</span>(r.gen_bool(<span class="number">1.0</span>), <span class="bool-val">true</span>); + } + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_rng_trait_object() { + <span class="kw">use </span><span class="kw">crate</span>::distributions::{Distribution, Standard}; + <span class="kw">let </span><span class="kw-2">mut </span>rng = rng(<span class="number">109</span>); + <span class="kw">let </span><span class="kw-2">mut </span>r = <span class="kw-2">&mut </span>rng <span class="kw">as </span><span class="kw-2">&mut </span><span class="kw">dyn </span>RngCore; + r.next_u32(); + r.gen::<i32>(); + <span class="macro">assert_eq!</span>(r.gen_range(<span class="number">0</span>..<span class="number">1</span>), <span class="number">0</span>); + <span class="kw">let </span>_c: u8 = Standard.sample(<span class="kw-2">&mut </span>r); + } + + <span class="attribute">#[test] + #[cfg(feature = <span class="string">"alloc"</span>)] + </span><span class="kw">fn </span>test_rng_boxed_trait() { + <span class="kw">use </span><span class="kw">crate</span>::distributions::{Distribution, Standard}; + <span class="kw">let </span>rng = rng(<span class="number">110</span>); + <span class="kw">let </span><span class="kw-2">mut </span>r = Box::new(rng) <span class="kw">as </span>Box<<span class="kw">dyn </span>RngCore>; + r.next_u32(); + r.gen::<i32>(); + <span class="macro">assert_eq!</span>(r.gen_range(<span class="number">0</span>..<span class="number">1</span>), <span class="number">0</span>); + <span class="kw">let </span>_c: u8 = Standard.sample(<span class="kw-2">&mut </span>r); + } + + <span class="attribute">#[test] + #[cfg_attr(miri, ignore)] </span><span class="comment">// Miri is too slow + </span><span class="kw">fn </span>test_gen_ratio_average() { + <span class="kw">const </span>NUM: u32 = <span class="number">3</span>; + <span class="kw">const </span>DENOM: u32 = <span class="number">10</span>; + <span class="kw">const </span>N: u32 = <span class="number">100_000</span>; + + <span class="kw">let </span><span class="kw-2">mut </span>sum: u32 = <span class="number">0</span>; + <span class="kw">let </span><span class="kw-2">mut </span>rng = rng(<span class="number">111</span>); + <span class="kw">for _ in </span><span class="number">0</span>..N { + <span class="kw">if </span>rng.gen_ratio(NUM, DENOM) { + sum += <span class="number">1</span>; + } + } + <span class="comment">// Have Binomial(N, NUM/DENOM) distribution + </span><span class="kw">let </span>expected = (NUM * N) / DENOM; <span class="comment">// exact integer + </span><span class="macro">assert!</span>(((sum - expected) <span class="kw">as </span>i32).abs() < <span class="number">500</span>); + } +} +</code></pre></div> +</section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="rand" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0 (69f9c33d7 2022-12-12) (Arch Linux rust 1:1.66.0-1)" ></div></body></html>
\ No newline at end of file diff --git a/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/rngs/adapter/mod.rs.html b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/rngs/adapter/mod.rs.html new file mode 100644 index 0000000..a272f93 --- /dev/null +++ b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/rngs/adapter/mod.rs.html @@ -0,0 +1,35 @@ +<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/home/pico/.local/share/cargo/registry/src/github.com-1ecc6299db9ec823/rand-0.8.5/src/rngs/adapter/mod.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>mod.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../../../normalize.css"><link rel="stylesheet" href="../../../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../../../ayu.css" disabled><link rel="stylesheet" href="../../../../dark.css" disabled><link rel="stylesheet" href="../../../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../../../storage.js"></script><script defer src="../../../../source-script.js"></script><script defer src="../../../../source-files.js"></script><script defer src="../../../../main.js"></script><noscript><link rel="stylesheet" href="../../../../noscript.css"></noscript><link rel="icon" href="https://www.rust-lang.org/favicon.ico"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../../../rand/index.html"> + <img src="https://www.rust-lang.org/logos/rust-logo-128x128-blk.png" alt="logo"></a><form class="search-form"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../../../wheel.svg"></a></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> +<span id="2">2</span> +<span id="3">3</span> +<span id="4">4</span> +<span id="5">5</span> +<span id="6">6</span> +<span id="7">7</span> +<span id="8">8</span> +<span id="9">9</span> +<span id="10">10</span> +<span id="11">11</span> +<span id="12">12</span> +<span id="13">13</span> +<span id="14">14</span> +<span id="15">15</span> +<span id="16">16</span> +</pre><pre class="rust"><code><span class="comment">// Copyright 2018 Developers of the Rand project. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +</span><span class="doccomment">//! Wrappers / adapters forming RNGs + +</span><span class="kw">mod </span>read; +<span class="kw">mod </span>reseeding; + +<span class="attribute">#[allow(deprecated)] +</span><span class="kw">pub use </span><span class="self">self</span>::read::{ReadError, ReadRng}; +<span class="kw">pub use </span><span class="self">self</span>::reseeding::ReseedingRng; +</code></pre></div> +</section></div></main><div id="rustdoc-vars" data-root-path="../../../../" data-current-crate="rand" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0 (69f9c33d7 2022-12-12) (Arch Linux rust 1:1.66.0-1)" ></div></body></html>
\ No newline at end of file diff --git a/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/rngs/adapter/read.rs.html b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/rngs/adapter/read.rs.html new file mode 100644 index 0000000..d16c0fb --- /dev/null +++ b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/rngs/adapter/read.rs.html @@ -0,0 +1,303 @@ +<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/home/pico/.local/share/cargo/registry/src/github.com-1ecc6299db9ec823/rand-0.8.5/src/rngs/adapter/read.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>read.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" 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src="../../../../source-files.js"></script><script defer src="../../../../main.js"></script><noscript><link rel="stylesheet" href="../../../../noscript.css"></noscript><link rel="icon" href="https://www.rust-lang.org/favicon.ico"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../../../rand/index.html"> + <img src="https://www.rust-lang.org/logos/rust-logo-128x128-blk.png" alt="logo"></a><form class="search-form"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../../../wheel.svg"></a></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> +<span id="2">2</span> +<span id="3">3</span> +<span id="4">4</span> +<span id="5">5</span> +<span id="6">6</span> +<span id="7">7</span> +<span id="8">8</span> +<span id="9">9</span> +<span id="10">10</span> +<span id="11">11</span> +<span id="12">12</span> +<span id="13">13</span> +<span id="14">14</span> +<span id="15">15</span> +<span id="16">16</span> +<span id="17">17</span> +<span id="18">18</span> +<span id="19">19</span> +<span id="20">20</span> +<span id="21">21</span> +<span id="22">22</span> +<span id="23">23</span> +<span id="24">24</span> +<span id="25">25</span> +<span id="26">26</span> +<span id="27">27</span> +<span id="28">28</span> +<span id="29">29</span> +<span id="30">30</span> +<span id="31">31</span> +<span id="32">32</span> +<span id="33">33</span> +<span id="34">34</span> +<span id="35">35</span> +<span id="36">36</span> +<span id="37">37</span> +<span id="38">38</span> +<span id="39">39</span> +<span id="40">40</span> +<span id="41">41</span> +<span id="42">42</span> +<span id="43">43</span> +<span id="44">44</span> +<span id="45">45</span> +<span id="46">46</span> +<span id="47">47</span> +<span id="48">48</span> +<span id="49">49</span> +<span id="50">50</span> +<span id="51">51</span> +<span id="52">52</span> +<span id="53">53</span> +<span id="54">54</span> +<span id="55">55</span> +<span id="56">56</span> +<span id="57">57</span> +<span id="58">58</span> +<span id="59">59</span> +<span id="60">60</span> +<span id="61">61</span> +<span id="62">62</span> +<span id="63">63</span> +<span id="64">64</span> +<span id="65">65</span> +<span id="66">66</span> +<span id="67">67</span> +<span id="68">68</span> +<span id="69">69</span> +<span id="70">70</span> +<span id="71">71</span> +<span id="72">72</span> +<span id="73">73</span> +<span id="74">74</span> +<span id="75">75</span> +<span id="76">76</span> +<span id="77">77</span> +<span id="78">78</span> +<span id="79">79</span> +<span id="80">80</span> +<span id="81">81</span> +<span id="82">82</span> +<span id="83">83</span> +<span id="84">84</span> +<span id="85">85</span> +<span id="86">86</span> +<span id="87">87</span> +<span id="88">88</span> +<span id="89">89</span> +<span id="90">90</span> +<span id="91">91</span> +<span id="92">92</span> +<span id="93">93</span> +<span id="94">94</span> +<span id="95">95</span> +<span id="96">96</span> +<span id="97">97</span> +<span id="98">98</span> +<span id="99">99</span> +<span id="100">100</span> +<span id="101">101</span> +<span id="102">102</span> +<span id="103">103</span> +<span id="104">104</span> +<span id="105">105</span> +<span id="106">106</span> +<span id="107">107</span> +<span id="108">108</span> +<span id="109">109</span> +<span id="110">110</span> +<span id="111">111</span> +<span id="112">112</span> +<span id="113">113</span> +<span id="114">114</span> +<span id="115">115</span> +<span id="116">116</span> +<span id="117">117</span> +<span id="118">118</span> +<span id="119">119</span> +<span id="120">120</span> +<span id="121">121</span> +<span id="122">122</span> +<span id="123">123</span> +<span id="124">124</span> +<span id="125">125</span> +<span id="126">126</span> +<span id="127">127</span> +<span id="128">128</span> +<span id="129">129</span> +<span id="130">130</span> +<span id="131">131</span> +<span id="132">132</span> +<span id="133">133</span> +<span id="134">134</span> +<span id="135">135</span> +<span id="136">136</span> +<span id="137">137</span> +<span id="138">138</span> +<span id="139">139</span> +<span id="140">140</span> +<span id="141">141</span> +<span id="142">142</span> +<span id="143">143</span> +<span id="144">144</span> +<span id="145">145</span> +<span id="146">146</span> +<span id="147">147</span> +<span id="148">148</span> +<span id="149">149</span> +<span id="150">150</span> +</pre><pre class="rust"><code><span class="comment">// Copyright 2018 Developers of the Rand project. +// Copyright 2013 The Rust Project Developers. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +</span><span class="doccomment">//! A wrapper around any Read to treat it as an RNG. + +</span><span class="attribute">#![allow(deprecated)] + +</span><span class="kw">use </span>std::fmt; +<span class="kw">use </span>std::io::Read; + +<span class="kw">use </span>rand_core::{impls, Error, RngCore}; + + +<span class="doccomment">/// An RNG that reads random bytes straight from any type supporting +/// [`std::io::Read`], for example files. +/// +/// This will work best with an infinite reader, but that is not required. +/// +/// This can be used with `/dev/urandom` on Unix but it is recommended to use +/// [`OsRng`] instead. +/// +/// # Panics +/// +/// `ReadRng` uses [`std::io::Read::read_exact`], which retries on interrupts. +/// All other errors from the underlying reader, including when it does not +/// have enough data, will only be reported through [`try_fill_bytes`]. +/// The other [`RngCore`] methods will panic in case of an error. +/// +/// [`OsRng`]: crate::rngs::OsRng +/// [`try_fill_bytes`]: RngCore::try_fill_bytes +</span><span class="attribute">#[derive(Debug)] +#[deprecated(since=<span class="string">"0.8.4"</span>, note=<span class="string">"removal due to lack of usage"</span>)] +</span><span class="kw">pub struct </span>ReadRng<R> { + reader: R, +} + +<span class="kw">impl</span><R: Read> ReadRng<R> { + <span class="doccomment">/// Create a new `ReadRng` from a `Read`. + </span><span class="kw">pub fn </span>new(r: R) -> ReadRng<R> { + ReadRng { reader: r } + } +} + +<span class="kw">impl</span><R: Read> RngCore <span class="kw">for </span>ReadRng<R> { + <span class="kw">fn </span>next_u32(<span class="kw-2">&mut </span><span class="self">self</span>) -> u32 { + impls::next_u32_via_fill(<span class="self">self</span>) + } + + <span class="kw">fn </span>next_u64(<span class="kw-2">&mut </span><span class="self">self</span>) -> u64 { + impls::next_u64_via_fill(<span class="self">self</span>) + } + + <span class="kw">fn </span>fill_bytes(<span class="kw-2">&mut </span><span class="self">self</span>, dest: <span class="kw-2">&mut </span>[u8]) { + <span class="self">self</span>.try_fill_bytes(dest).unwrap_or_else(|err| { + <span class="macro">panic!</span>( + <span class="string">"reading random bytes from Read implementation failed; error: {}"</span>, + err + ) + }); + } + + <span class="kw">fn </span>try_fill_bytes(<span class="kw-2">&mut </span><span class="self">self</span>, dest: <span class="kw-2">&mut </span>[u8]) -> <span class="prelude-ty">Result</span><(), Error> { + <span class="kw">if </span>dest.is_empty() { + <span class="kw">return </span><span class="prelude-val">Ok</span>(()); + } + <span class="comment">// Use `std::io::read_exact`, which retries on `ErrorKind::Interrupted`. + </span><span class="self">self</span>.reader + .read_exact(dest) + .map_err(|e| Error::new(ReadError(e))) + } +} + +<span class="doccomment">/// `ReadRng` error type +</span><span class="attribute">#[derive(Debug)] +#[deprecated(since=<span class="string">"0.8.4"</span>)] +</span><span class="kw">pub struct </span>ReadError(std::io::Error); + +<span class="kw">impl </span>fmt::Display <span class="kw">for </span>ReadError { + <span class="kw">fn </span>fmt(<span class="kw-2">&</span><span class="self">self</span>, f: <span class="kw-2">&mut </span>fmt::Formatter) -> fmt::Result { + <span class="macro">write!</span>(f, <span class="string">"ReadError: {}"</span>, <span class="self">self</span>.<span class="number">0</span>) + } +} + +<span class="kw">impl </span>std::error::Error <span class="kw">for </span>ReadError { + <span class="kw">fn </span>source(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><<span class="kw-2">&</span>(<span class="kw">dyn </span>std::error::Error + <span class="lifetime">'static</span>)> { + <span class="prelude-val">Some</span>(<span class="kw-2">&</span><span class="self">self</span>.<span class="number">0</span>) + } +} + + +<span class="attribute">#[cfg(test)] +</span><span class="kw">mod </span>test { + <span class="kw">use </span>std::println; + + <span class="kw">use </span><span class="kw">super</span>::ReadRng; + <span class="kw">use </span><span class="kw">crate</span>::RngCore; + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_reader_rng_u64() { + <span class="comment">// transmute from the target to avoid endianness concerns. + </span><span class="attribute">#[rustfmt::skip] + </span><span class="kw">let </span>v = [<span class="number">0u8</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">1</span>, + <span class="number">0</span>, <span class="number">4</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">3</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">2</span>, + <span class="number">5</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>]; + <span class="kw">let </span><span class="kw-2">mut </span>rng = ReadRng::new(<span class="kw-2">&</span>v[..]); + + <span class="macro">assert_eq!</span>(rng.next_u64(), <span class="number">1 </span><< <span class="number">56</span>); + <span class="macro">assert_eq!</span>(rng.next_u64(), (<span class="number">2 </span><< <span class="number">56</span>) + (<span class="number">3 </span><< <span class="number">32</span>) + (<span class="number">4 </span><< <span class="number">8</span>)); + <span class="macro">assert_eq!</span>(rng.next_u64(), <span class="number">5</span>); + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_reader_rng_u32() { + <span class="kw">let </span>v = [<span class="number">0u8</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">1</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">2</span>, <span class="number">0</span>, <span class="number">3</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>]; + <span class="kw">let </span><span class="kw-2">mut </span>rng = ReadRng::new(<span class="kw-2">&</span>v[..]); + + <span class="macro">assert_eq!</span>(rng.next_u32(), <span class="number">1 </span><< <span class="number">24</span>); + <span class="macro">assert_eq!</span>(rng.next_u32(), <span class="number">2 </span><< <span class="number">16</span>); + <span class="macro">assert_eq!</span>(rng.next_u32(), <span class="number">3</span>); + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_reader_rng_fill_bytes() { + <span class="kw">let </span>v = [<span class="number">1u8</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>, <span class="number">6</span>, <span class="number">7</span>, <span class="number">8</span>]; + <span class="kw">let </span><span class="kw-2">mut </span>w = [<span class="number">0u8</span>; <span class="number">8</span>]; + + <span class="kw">let </span><span class="kw-2">mut </span>rng = ReadRng::new(<span class="kw-2">&</span>v[..]); + rng.fill_bytes(<span class="kw-2">&mut </span>w); + + <span class="macro">assert!</span>(v == w); + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_reader_rng_insufficient_bytes() { + <span class="kw">let </span>v = [<span class="number">1u8</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>, <span class="number">6</span>, <span class="number">7</span>, <span class="number">8</span>]; + <span class="kw">let </span><span class="kw-2">mut </span>w = [<span class="number">0u8</span>; <span class="number">9</span>]; + + <span class="kw">let </span><span class="kw-2">mut </span>rng = ReadRng::new(<span class="kw-2">&</span>v[..]); + + <span class="kw">let </span>result = rng.try_fill_bytes(<span class="kw-2">&mut </span>w); + <span class="macro">assert!</span>(result.is_err()); + <span class="macro">println!</span>(<span class="string">"Error: {}"</span>, result.unwrap_err()); + } +} +</code></pre></div> +</section></div></main><div id="rustdoc-vars" data-root-path="../../../../" data-current-crate="rand" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0 (69f9c33d7 2022-12-12) (Arch Linux rust 1:1.66.0-1)" ></div></body></html>
\ No newline at end of file diff --git a/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/rngs/adapter/reseeding.rs.html b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/rngs/adapter/reseeding.rs.html new file mode 100644 index 0000000..93f4eaf --- /dev/null +++ b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/rngs/adapter/reseeding.rs.html @@ -0,0 +1,775 @@ +<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/home/pico/.local/share/cargo/registry/src/github.com-1ecc6299db9ec823/rand-0.8.5/src/rngs/adapter/reseeding.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>reseeding.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" 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title="settings"><img width="22" height="22" alt="Change settings" src="../../../../wheel.svg"></a></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> +<span id="2">2</span> +<span id="3">3</span> +<span id="4">4</span> +<span id="5">5</span> +<span id="6">6</span> +<span id="7">7</span> +<span id="8">8</span> +<span id="9">9</span> +<span id="10">10</span> +<span id="11">11</span> +<span id="12">12</span> +<span id="13">13</span> +<span id="14">14</span> +<span id="15">15</span> +<span id="16">16</span> +<span id="17">17</span> +<span id="18">18</span> +<span id="19">19</span> +<span id="20">20</span> +<span id="21">21</span> +<span id="22">22</span> +<span id="23">23</span> +<span id="24">24</span> +<span id="25">25</span> +<span id="26">26</span> +<span id="27">27</span> +<span id="28">28</span> +<span id="29">29</span> +<span id="30">30</span> +<span id="31">31</span> +<span id="32">32</span> 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+<span id="371">371</span> +<span id="372">372</span> +<span id="373">373</span> +<span id="374">374</span> +<span id="375">375</span> +<span id="376">376</span> +<span id="377">377</span> +<span id="378">378</span> +<span id="379">379</span> +<span id="380">380</span> +<span id="381">381</span> +<span id="382">382</span> +<span id="383">383</span> +<span id="384">384</span> +<span id="385">385</span> +<span id="386">386</span> +</pre><pre class="rust"><code><span class="comment">// Copyright 2018 Developers of the Rand project. +// Copyright 2013 The Rust Project Developers. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +</span><span class="doccomment">//! A wrapper around another PRNG that reseeds it after it +//! generates a certain number of random bytes. + +</span><span class="kw">use </span>core::mem::size_of; + +<span class="kw">use </span>rand_core::block::{BlockRng, BlockRngCore}; +<span class="kw">use </span>rand_core::{CryptoRng, Error, RngCore, SeedableRng}; + +<span class="doccomment">/// A wrapper around any PRNG that implements [`BlockRngCore`], that adds the +/// ability to reseed it. +/// +/// `ReseedingRng` reseeds the underlying PRNG in the following cases: +/// +/// - On a manual call to [`reseed()`]. +/// - After `clone()`, the clone will be reseeded on first use. +/// - When a process is forked on UNIX, the RNGs in both the parent and child +/// processes will be reseeded just before the next call to +/// [`BlockRngCore::generate`], i.e. "soon". For ChaCha and Hc128 this is a +/// maximum of fifteen `u32` values before reseeding. +/// - After the PRNG has generated a configurable number of random bytes. +/// +/// # When should reseeding after a fixed number of generated bytes be used? +/// +/// Reseeding after a fixed number of generated bytes is never strictly +/// *necessary*. Cryptographic PRNGs don't have a limited number of bytes they +/// can output, or at least not a limit reachable in any practical way. There is +/// no such thing as 'running out of entropy'. +/// +/// Occasionally reseeding can be seen as some form of 'security in depth'. Even +/// if in the future a cryptographic weakness is found in the CSPRNG being used, +/// or a flaw in the implementation, occasionally reseeding should make +/// exploiting it much more difficult or even impossible. +/// +/// Use [`ReseedingRng::new`] with a `threshold` of `0` to disable reseeding +/// after a fixed number of generated bytes. +/// +/// # Limitations +/// +/// It is recommended that a `ReseedingRng` (including `ThreadRng`) not be used +/// from a fork handler. +/// Use `OsRng` or `getrandom`, or defer your use of the RNG until later. +/// +/// # Error handling +/// +/// Although unlikely, reseeding the wrapped PRNG can fail. `ReseedingRng` will +/// never panic but try to handle the error intelligently through some +/// combination of retrying and delaying reseeding until later. +/// If handling the source error fails `ReseedingRng` will continue generating +/// data from the wrapped PRNG without reseeding. +/// +/// Manually calling [`reseed()`] will not have this retry or delay logic, but +/// reports the error. +/// +/// # Example +/// +/// ``` +/// use rand::prelude::*; +/// use rand_chacha::ChaCha20Core; // Internal part of ChaChaRng that +/// // implements BlockRngCore +/// use rand::rngs::OsRng; +/// use rand::rngs::adapter::ReseedingRng; +/// +/// let prng = ChaCha20Core::from_entropy(); +/// let mut reseeding_rng = ReseedingRng::new(prng, 0, OsRng); +/// +/// println!("{}", reseeding_rng.gen::<u64>()); +/// +/// let mut cloned_rng = reseeding_rng.clone(); +/// assert!(reseeding_rng.gen::<u64>() != cloned_rng.gen::<u64>()); +/// ``` +/// +/// [`BlockRngCore`]: rand_core::block::BlockRngCore +/// [`ReseedingRng::new`]: ReseedingRng::new +/// [`reseed()`]: ReseedingRng::reseed +</span><span class="attribute">#[derive(Debug)] +</span><span class="kw">pub struct </span>ReseedingRng<R, Rsdr>(BlockRng<ReseedingCore<R, Rsdr>>) +<span class="kw">where + </span>R: BlockRngCore + SeedableRng, + Rsdr: RngCore; + +<span class="kw">impl</span><R, Rsdr> ReseedingRng<R, Rsdr> +<span class="kw">where + </span>R: BlockRngCore + SeedableRng, + Rsdr: RngCore, +{ + <span class="doccomment">/// Create a new `ReseedingRng` from an existing PRNG, combined with a RNG + /// to use as reseeder. + /// + /// `threshold` sets the number of generated bytes after which to reseed the + /// PRNG. Set it to zero to never reseed based on the number of generated + /// values. + </span><span class="kw">pub fn </span>new(rng: R, threshold: u64, reseeder: Rsdr) -> <span class="self">Self </span>{ + ReseedingRng(BlockRng::new(ReseedingCore::new(rng, threshold, reseeder))) + } + + <span class="doccomment">/// Reseed the internal PRNG. + </span><span class="kw">pub fn </span>reseed(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Result</span><(), Error> { + <span class="self">self</span>.<span class="number">0</span>.core.reseed() + } +} + +<span class="comment">// TODO: this should be implemented for any type where the inner type +// implements RngCore, but we can't specify that because ReseedingCore is private +</span><span class="kw">impl</span><R, Rsdr: RngCore> RngCore <span class="kw">for </span>ReseedingRng<R, Rsdr> +<span class="kw">where + </span>R: BlockRngCore<Item = u32> + SeedableRng, + <R <span class="kw">as </span>BlockRngCore>::Results: AsRef<[u32]> + AsMut<[u32]>, +{ + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>next_u32(<span class="kw-2">&mut </span><span class="self">self</span>) -> u32 { + <span class="self">self</span>.<span class="number">0</span>.next_u32() + } + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>next_u64(<span class="kw-2">&mut </span><span class="self">self</span>) -> u64 { + <span class="self">self</span>.<span class="number">0</span>.next_u64() + } + + <span class="kw">fn </span>fill_bytes(<span class="kw-2">&mut </span><span class="self">self</span>, dest: <span class="kw-2">&mut </span>[u8]) { + <span class="self">self</span>.<span class="number">0</span>.fill_bytes(dest) + } + + <span class="kw">fn </span>try_fill_bytes(<span class="kw-2">&mut </span><span class="self">self</span>, dest: <span class="kw-2">&mut </span>[u8]) -> <span class="prelude-ty">Result</span><(), Error> { + <span class="self">self</span>.<span class="number">0</span>.try_fill_bytes(dest) + } +} + +<span class="kw">impl</span><R, Rsdr> Clone <span class="kw">for </span>ReseedingRng<R, Rsdr> +<span class="kw">where + </span>R: BlockRngCore + SeedableRng + Clone, + Rsdr: RngCore + Clone, +{ + <span class="kw">fn </span>clone(<span class="kw-2">&</span><span class="self">self</span>) -> ReseedingRng<R, Rsdr> { + <span class="comment">// Recreating `BlockRng` seems easier than cloning it and resetting + // the index. + </span>ReseedingRng(BlockRng::new(<span class="self">self</span>.<span class="number">0</span>.core.clone())) + } +} + +<span class="kw">impl</span><R, Rsdr> CryptoRng <span class="kw">for </span>ReseedingRng<R, Rsdr> +<span class="kw">where + </span>R: BlockRngCore + SeedableRng + CryptoRng, + Rsdr: RngCore + CryptoRng, +{ +} + +<span class="attribute">#[derive(Debug)] +</span><span class="kw">struct </span>ReseedingCore<R, Rsdr> { + inner: R, + reseeder: Rsdr, + threshold: i64, + bytes_until_reseed: i64, + fork_counter: usize, +} + +<span class="kw">impl</span><R, Rsdr> BlockRngCore <span class="kw">for </span>ReseedingCore<R, Rsdr> +<span class="kw">where + </span>R: BlockRngCore + SeedableRng, + Rsdr: RngCore, +{ + <span class="kw">type </span>Item = <R <span class="kw">as </span>BlockRngCore>::Item; + <span class="kw">type </span>Results = <R <span class="kw">as </span>BlockRngCore>::Results; + + <span class="kw">fn </span>generate(<span class="kw-2">&mut </span><span class="self">self</span>, results: <span class="kw-2">&mut </span><span class="self">Self</span>::Results) { + <span class="kw">let </span>global_fork_counter = fork::get_fork_counter(); + <span class="kw">if </span><span class="self">self</span>.bytes_until_reseed <= <span class="number">0 </span>|| <span class="self">self</span>.is_forked(global_fork_counter) { + <span class="comment">// We get better performance by not calling only `reseed` here + // and continuing with the rest of the function, but by directly + // returning from a non-inlined function. + </span><span class="kw">return </span><span class="self">self</span>.reseed_and_generate(results, global_fork_counter); + } + <span class="kw">let </span>num_bytes = results.as_ref().len() * size_of::<<span class="self">Self</span>::Item>(); + <span class="self">self</span>.bytes_until_reseed -= num_bytes <span class="kw">as </span>i64; + <span class="self">self</span>.inner.generate(results); + } +} + +<span class="kw">impl</span><R, Rsdr> ReseedingCore<R, Rsdr> +<span class="kw">where + </span>R: BlockRngCore + SeedableRng, + Rsdr: RngCore, +{ + <span class="doccomment">/// Create a new `ReseedingCore`. + </span><span class="kw">fn </span>new(rng: R, threshold: u64, reseeder: Rsdr) -> <span class="self">Self </span>{ + <span class="kw">use </span>::core::i64::MAX; + fork::register_fork_handler(); + + <span class="comment">// Because generating more values than `i64::MAX` takes centuries on + // current hardware, we just clamp to that value. + // Also we set a threshold of 0, which indicates no limit, to that + // value. + </span><span class="kw">let </span>threshold = <span class="kw">if </span>threshold == <span class="number">0 </span>{ + MAX + } <span class="kw">else if </span>threshold <= MAX <span class="kw">as </span>u64 { + threshold <span class="kw">as </span>i64 + } <span class="kw">else </span>{ + MAX + }; + + ReseedingCore { + inner: rng, + reseeder, + threshold: threshold <span class="kw">as </span>i64, + bytes_until_reseed: threshold <span class="kw">as </span>i64, + fork_counter: <span class="number">0</span>, + } + } + + <span class="doccomment">/// Reseed the internal PRNG. + </span><span class="kw">fn </span>reseed(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Result</span><(), Error> { + R::from_rng(<span class="kw-2">&mut </span><span class="self">self</span>.reseeder).map(|result| { + <span class="self">self</span>.bytes_until_reseed = <span class="self">self</span>.threshold; + <span class="self">self</span>.inner = result + }) + } + + <span class="kw">fn </span>is_forked(<span class="kw-2">&</span><span class="self">self</span>, global_fork_counter: usize) -> bool { + <span class="comment">// In theory, on 32-bit platforms, it is possible for + // `global_fork_counter` to wrap around after ~4e9 forks. + // + // This check will detect a fork in the normal case where + // `fork_counter < global_fork_counter`, and also when the difference + // between both is greater than `isize::MAX` (wrapped around). + // + // It will still fail to detect a fork if there have been more than + // `isize::MAX` forks, without any reseed in between. Seems unlikely + // enough. + </span>(<span class="self">self</span>.fork_counter.wrapping_sub(global_fork_counter) <span class="kw">as </span>isize) < <span class="number">0 + </span>} + + <span class="attribute">#[inline(never)] + </span><span class="kw">fn </span>reseed_and_generate( + <span class="kw-2">&mut </span><span class="self">self</span>, results: <span class="kw-2">&mut </span><<span class="self">Self </span><span class="kw">as </span>BlockRngCore>::Results, global_fork_counter: usize, + ) { + <span class="attribute">#![allow(clippy::if_same_then_else)] </span><span class="comment">// false positive + </span><span class="kw">if </span><span class="self">self</span>.is_forked(global_fork_counter) { + <span class="macro">info!</span>(<span class="string">"Fork detected, reseeding RNG"</span>); + } <span class="kw">else </span>{ + <span class="macro">trace!</span>(<span class="string">"Reseeding RNG (periodic reseed)"</span>); + } + + <span class="kw">let </span>num_bytes = results.as_ref().len() * size_of::<<R <span class="kw">as </span>BlockRngCore>::Item>(); + + <span class="kw">if let </span><span class="prelude-val">Err</span>(e) = <span class="self">self</span>.reseed() { + <span class="macro">warn!</span>(<span class="string">"Reseeding RNG failed: {}"</span>, e); + <span class="kw">let _ </span>= e; + } + <span class="self">self</span>.fork_counter = global_fork_counter; + + <span class="self">self</span>.bytes_until_reseed = <span class="self">self</span>.threshold - num_bytes <span class="kw">as </span>i64; + <span class="self">self</span>.inner.generate(results); + } +} + +<span class="kw">impl</span><R, Rsdr> Clone <span class="kw">for </span>ReseedingCore<R, Rsdr> +<span class="kw">where + </span>R: BlockRngCore + SeedableRng + Clone, + Rsdr: RngCore + Clone, +{ + <span class="kw">fn </span>clone(<span class="kw-2">&</span><span class="self">self</span>) -> ReseedingCore<R, Rsdr> { + ReseedingCore { + inner: <span class="self">self</span>.inner.clone(), + reseeder: <span class="self">self</span>.reseeder.clone(), + threshold: <span class="self">self</span>.threshold, + bytes_until_reseed: <span class="number">0</span>, <span class="comment">// reseed clone on first use + </span>fork_counter: <span class="self">self</span>.fork_counter, + } + } +} + +<span class="kw">impl</span><R, Rsdr> CryptoRng <span class="kw">for </span>ReseedingCore<R, Rsdr> +<span class="kw">where + </span>R: BlockRngCore + SeedableRng + CryptoRng, + Rsdr: RngCore + CryptoRng, +{ +} + + +<span class="attribute">#[cfg(all(unix, not(target_os = <span class="string">"emscripten"</span>)))] +</span><span class="kw">mod </span>fork { + <span class="kw">use </span>core::sync::atomic::{AtomicUsize, Ordering}; + <span class="kw">use </span>std::sync::Once; + + <span class="comment">// Fork protection + // + // We implement fork protection on Unix using `pthread_atfork`. + // When the process is forked, we increment `RESEEDING_RNG_FORK_COUNTER`. + // Every `ReseedingRng` stores the last known value of the static in + // `fork_counter`. If the cached `fork_counter` is less than + // `RESEEDING_RNG_FORK_COUNTER`, it is time to reseed this RNG. + // + // If reseeding fails, we don't deal with this by setting a delay, but just + // don't update `fork_counter`, so a reseed is attempted as soon as + // possible. + + </span><span class="kw">static </span>RESEEDING_RNG_FORK_COUNTER: AtomicUsize = AtomicUsize::new(<span class="number">0</span>); + + <span class="kw">pub fn </span>get_fork_counter() -> usize { + RESEEDING_RNG_FORK_COUNTER.load(Ordering::Relaxed) + } + + <span class="kw">extern </span><span class="string">"C" </span><span class="kw">fn </span>fork_handler() { + <span class="comment">// Note: fetch_add is defined to wrap on overflow + // (which is what we want). + </span>RESEEDING_RNG_FORK_COUNTER.fetch_add(<span class="number">1</span>, Ordering::Relaxed); + } + + <span class="kw">pub fn </span>register_fork_handler() { + <span class="kw">static </span>REGISTER: Once = Once::new(); + REGISTER.call_once(|| { + <span class="comment">// Bump the counter before and after forking (see #1169): + </span><span class="kw">let </span>ret = <span class="kw">unsafe </span>{ libc::pthread_atfork( + <span class="prelude-val">Some</span>(fork_handler), + <span class="prelude-val">Some</span>(fork_handler), + <span class="prelude-val">Some</span>(fork_handler), + ) }; + <span class="kw">if </span>ret != <span class="number">0 </span>{ + <span class="macro">panic!</span>(<span class="string">"libc::pthread_atfork failed with code {}"</span>, ret); + } + }); + } +} + +<span class="attribute">#[cfg(not(all(unix, not(target_os = <span class="string">"emscripten"</span>))))] +</span><span class="kw">mod </span>fork { + <span class="kw">pub fn </span>get_fork_counter() -> usize { + <span class="number">0 + </span>} + <span class="kw">pub fn </span>register_fork_handler() {} +} + + +<span class="attribute">#[cfg(feature = <span class="string">"std_rng"</span>)] +#[cfg(test)] +</span><span class="kw">mod </span>test { + <span class="kw">use </span><span class="kw">super</span>::ReseedingRng; + <span class="kw">use </span><span class="kw">crate</span>::rngs::mock::StepRng; + <span class="kw">use </span><span class="kw">crate</span>::rngs::std::Core; + <span class="kw">use crate</span>::{Rng, SeedableRng}; + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_reseeding() { + <span class="kw">let </span><span class="kw-2">mut </span>zero = StepRng::new(<span class="number">0</span>, <span class="number">0</span>); + <span class="kw">let </span>rng = Core::from_rng(<span class="kw-2">&mut </span>zero).unwrap(); + <span class="kw">let </span>thresh = <span class="number">1</span>; <span class="comment">// reseed every time the buffer is exhausted + </span><span class="kw">let </span><span class="kw-2">mut </span>reseeding = ReseedingRng::new(rng, thresh, zero); + + <span class="comment">// RNG buffer size is [u32; 64] + // Debug is only implemented up to length 32 so use two arrays + </span><span class="kw">let </span><span class="kw-2">mut </span>buf = ([<span class="number">0u32</span>; <span class="number">32</span>], [<span class="number">0u32</span>; <span class="number">32</span>]); + reseeding.fill(<span class="kw-2">&mut </span>buf.<span class="number">0</span>); + reseeding.fill(<span class="kw-2">&mut </span>buf.<span class="number">1</span>); + <span class="kw">let </span>seq = buf; + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">10 </span>{ + reseeding.fill(<span class="kw-2">&mut </span>buf.<span class="number">0</span>); + reseeding.fill(<span class="kw-2">&mut </span>buf.<span class="number">1</span>); + <span class="macro">assert_eq!</span>(buf, seq); + } + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_clone_reseeding() { + <span class="attribute">#![allow(clippy::redundant_clone)] + + </span><span class="kw">let </span><span class="kw-2">mut </span>zero = StepRng::new(<span class="number">0</span>, <span class="number">0</span>); + <span class="kw">let </span>rng = Core::from_rng(<span class="kw-2">&mut </span>zero).unwrap(); + <span class="kw">let </span><span class="kw-2">mut </span>rng1 = ReseedingRng::new(rng, <span class="number">32 </span>* <span class="number">4</span>, zero); + + <span class="kw">let </span>first: u32 = rng1.gen(); + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">10 </span>{ + <span class="kw">let _ </span>= rng1.gen::<u32>(); + } + + <span class="kw">let </span><span class="kw-2">mut </span>rng2 = rng1.clone(); + <span class="macro">assert_eq!</span>(first, rng2.gen::<u32>()); + } +} +</code></pre></div> +</section></div></main><div id="rustdoc-vars" data-root-path="../../../../" data-current-crate="rand" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0 (69f9c33d7 2022-12-12) (Arch Linux rust 1:1.66.0-1)" ></div></body></html>
\ No newline at end of file diff --git a/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/rngs/mock.rs.html b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/rngs/mock.rs.html new file mode 100644 index 0000000..819baf1 --- /dev/null +++ b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/rngs/mock.rs.html @@ -0,0 +1,177 @@ +<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/home/pico/.local/share/cargo/registry/src/github.com-1ecc6299db9ec823/rand-0.8.5/src/rngs/mock.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>mock.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin 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src="../../../wheel.svg"></a></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> +<span id="2">2</span> +<span id="3">3</span> +<span id="4">4</span> +<span id="5">5</span> +<span id="6">6</span> +<span id="7">7</span> +<span id="8">8</span> +<span id="9">9</span> +<span id="10">10</span> +<span id="11">11</span> +<span id="12">12</span> +<span id="13">13</span> +<span id="14">14</span> +<span id="15">15</span> +<span id="16">16</span> +<span id="17">17</span> +<span id="18">18</span> +<span id="19">19</span> +<span id="20">20</span> +<span id="21">21</span> +<span id="22">22</span> +<span id="23">23</span> +<span id="24">24</span> +<span id="25">25</span> +<span id="26">26</span> +<span id="27">27</span> +<span id="28">28</span> +<span id="29">29</span> +<span id="30">30</span> +<span id="31">31</span> +<span id="32">32</span> +<span id="33">33</span> +<span id="34">34</span> +<span 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id="75">75</span> +<span id="76">76</span> +<span id="77">77</span> +<span id="78">78</span> +<span id="79">79</span> +<span id="80">80</span> +<span id="81">81</span> +<span id="82">82</span> +<span id="83">83</span> +<span id="84">84</span> +<span id="85">85</span> +<span id="86">86</span> +<span id="87">87</span> +</pre><pre class="rust"><code><span class="comment">// Copyright 2018 Developers of the Rand project. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +</span><span class="doccomment">//! Mock random number generator + +</span><span class="kw">use </span>rand_core::{impls, Error, RngCore}; + +<span class="attribute">#[cfg(feature = <span class="string">"serde1"</span>)] +</span><span class="kw">use </span>serde::{Serialize, Deserialize}; + +<span class="doccomment">/// A simple implementation of `RngCore` for testing purposes. +/// +/// This generates an arithmetic sequence (i.e. adds a constant each step) +/// over a `u64` number, using wrapping arithmetic. If the increment is 0 +/// the generator yields a constant. +/// +/// ``` +/// use rand::Rng; +/// use rand::rngs::mock::StepRng; +/// +/// let mut my_rng = StepRng::new(2, 1); +/// let sample: [u64; 3] = my_rng.gen(); +/// assert_eq!(sample, [2, 3, 4]); +/// ``` +</span><span class="attribute">#[derive(Debug, Clone, PartialEq, Eq)] +#[cfg_attr(feature = <span class="string">"serde1"</span>, derive(Serialize, Deserialize))] +</span><span class="kw">pub struct </span>StepRng { + v: u64, + a: u64, +} + +<span class="kw">impl </span>StepRng { + <span class="doccomment">/// Create a `StepRng`, yielding an arithmetic sequence starting with + /// `initial` and incremented by `increment` each time. + </span><span class="kw">pub fn </span>new(initial: u64, increment: u64) -> <span class="self">Self </span>{ + StepRng { + v: initial, + a: increment, + } + } +} + +<span class="kw">impl </span>RngCore <span class="kw">for </span>StepRng { + <span class="attribute">#[inline] + </span><span class="kw">fn </span>next_u32(<span class="kw-2">&mut </span><span class="self">self</span>) -> u32 { + <span class="self">self</span>.next_u64() <span class="kw">as </span>u32 + } + + <span class="attribute">#[inline] + </span><span class="kw">fn </span>next_u64(<span class="kw-2">&mut </span><span class="self">self</span>) -> u64 { + <span class="kw">let </span>result = <span class="self">self</span>.v; + <span class="self">self</span>.v = <span class="self">self</span>.v.wrapping_add(<span class="self">self</span>.a); + result + } + + <span class="attribute">#[inline] + </span><span class="kw">fn </span>fill_bytes(<span class="kw-2">&mut </span><span class="self">self</span>, dest: <span class="kw-2">&mut </span>[u8]) { + impls::fill_bytes_via_next(<span class="self">self</span>, dest); + } + + <span class="attribute">#[inline] + </span><span class="kw">fn </span>try_fill_bytes(<span class="kw-2">&mut </span><span class="self">self</span>, dest: <span class="kw-2">&mut </span>[u8]) -> <span class="prelude-ty">Result</span><(), Error> { + <span class="self">self</span>.fill_bytes(dest); + <span class="prelude-val">Ok</span>(()) + } +} + +<span class="attribute">#[cfg(test)] +</span><span class="kw">mod </span>tests { + <span class="attribute">#[test] + #[cfg(feature = <span class="string">"serde1"</span>)] + </span><span class="kw">fn </span>test_serialization_step_rng() { + <span class="kw">use </span><span class="kw">super</span>::StepRng; + + <span class="kw">let </span>some_rng = StepRng::new(<span class="number">42</span>, <span class="number">7</span>); + <span class="kw">let </span>de_some_rng: StepRng = + bincode::deserialize(<span class="kw-2">&</span>bincode::serialize(<span class="kw-2">&</span>some_rng).unwrap()).unwrap(); + <span class="macro">assert_eq!</span>(some_rng.v, de_some_rng.v); + <span class="macro">assert_eq!</span>(some_rng.a, de_some_rng.a); + + } +} +</code></pre></div> +</section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="rand" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0 (69f9c33d7 2022-12-12) (Arch Linux rust 1:1.66.0-1)" ></div></body></html>
\ No newline at end of file diff --git a/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/rngs/mod.rs.html b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/rngs/mod.rs.html new file mode 100644 index 0000000..48767fa --- /dev/null +++ b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/rngs/mod.rs.html @@ -0,0 +1,241 @@ +<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/home/pico/.local/share/cargo/registry/src/github.com-1ecc6299db9ec823/rand-0.8.5/src/rngs/mod.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>mod.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../../normalize.css"><link rel="stylesheet" href="../../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../../ayu.css" disabled><link rel="stylesheet" href="../../../dark.css" disabled><link rel="stylesheet" href="../../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../../storage.js"></script><script defer src="../../../source-script.js"></script><script defer src="../../../source-files.js"></script><script defer src="../../../main.js"></script><noscript><link rel="stylesheet" href="../../../noscript.css"></noscript><link rel="icon" href="https://www.rust-lang.org/favicon.ico"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../../rand/index.html"> + <img src="https://www.rust-lang.org/logos/rust-logo-128x128-blk.png" alt="logo"></a><form class="search-form"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../../wheel.svg"></a></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> +<span id="2">2</span> +<span id="3">3</span> +<span id="4">4</span> +<span id="5">5</span> +<span id="6">6</span> +<span id="7">7</span> +<span id="8">8</span> +<span id="9">9</span> +<span id="10">10</span> +<span id="11">11</span> +<span id="12">12</span> +<span id="13">13</span> +<span id="14">14</span> +<span id="15">15</span> +<span id="16">16</span> +<span id="17">17</span> +<span id="18">18</span> +<span id="19">19</span> +<span id="20">20</span> +<span id="21">21</span> +<span id="22">22</span> +<span id="23">23</span> +<span id="24">24</span> +<span id="25">25</span> +<span id="26">26</span> +<span id="27">27</span> +<span id="28">28</span> +<span id="29">29</span> +<span id="30">30</span> +<span id="31">31</span> +<span id="32">32</span> +<span id="33">33</span> +<span id="34">34</span> +<span 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id="75">75</span> +<span id="76">76</span> +<span id="77">77</span> +<span id="78">78</span> +<span id="79">79</span> +<span id="80">80</span> +<span id="81">81</span> +<span id="82">82</span> +<span id="83">83</span> +<span id="84">84</span> +<span id="85">85</span> +<span id="86">86</span> +<span id="87">87</span> +<span id="88">88</span> +<span id="89">89</span> +<span id="90">90</span> +<span id="91">91</span> +<span id="92">92</span> +<span id="93">93</span> +<span id="94">94</span> +<span id="95">95</span> +<span id="96">96</span> +<span id="97">97</span> +<span id="98">98</span> +<span id="99">99</span> +<span id="100">100</span> +<span id="101">101</span> +<span id="102">102</span> +<span id="103">103</span> +<span id="104">104</span> +<span id="105">105</span> +<span id="106">106</span> +<span id="107">107</span> +<span id="108">108</span> +<span id="109">109</span> +<span id="110">110</span> +<span id="111">111</span> +<span id="112">112</span> +<span id="113">113</span> +<span id="114">114</span> +<span id="115">115</span> +<span id="116">116</span> +<span id="117">117</span> +<span id="118">118</span> +<span id="119">119</span> +</pre><pre class="rust"><code><span class="comment">// Copyright 2018 Developers of the Rand project. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +</span><span class="doccomment">//! Random number generators and adapters +//! +//! ## Background: Random number generators (RNGs) +//! +//! Computers cannot produce random numbers from nowhere. We classify +//! random number generators as follows: +//! +//! - "True" random number generators (TRNGs) use hard-to-predict data sources +//! (e.g. the high-resolution parts of event timings and sensor jitter) to +//! harvest random bit-sequences, apply algorithms to remove bias and +//! estimate available entropy, then combine these bits into a byte-sequence +//! or an entropy pool. This job is usually done by the operating system or +//! a hardware generator (HRNG). +//! - "Pseudo"-random number generators (PRNGs) use algorithms to transform a +//! seed into a sequence of pseudo-random numbers. These generators can be +//! fast and produce well-distributed unpredictable random numbers (or not). +//! They are usually deterministic: given algorithm and seed, the output +//! sequence can be reproduced. They have finite period and eventually loop; +//! with many algorithms this period is fixed and can be proven sufficiently +//! long, while others are chaotic and the period depends on the seed. +//! - "Cryptographically secure" pseudo-random number generators (CSPRNGs) +//! are the sub-set of PRNGs which are secure. Security of the generator +//! relies both on hiding the internal state and using a strong algorithm. +//! +//! ## Traits and functionality +//! +//! All RNGs implement the [`RngCore`] trait, as a consequence of which the +//! [`Rng`] extension trait is automatically implemented. Secure RNGs may +//! additionally implement the [`CryptoRng`] trait. +//! +//! All PRNGs require a seed to produce their random number sequence. The +//! [`SeedableRng`] trait provides three ways of constructing PRNGs: +//! +//! - `from_seed` accepts a type specific to the PRNG +//! - `from_rng` allows a PRNG to be seeded from any other RNG +//! - `seed_from_u64` allows any PRNG to be seeded from a `u64` insecurely +//! - `from_entropy` securely seeds a PRNG from fresh entropy +//! +//! Use the [`rand_core`] crate when implementing your own RNGs. +//! +//! ## Our generators +//! +//! This crate provides several random number generators: +//! +//! - [`OsRng`] is an interface to the operating system's random number +//! source. Typically the operating system uses a CSPRNG with entropy +//! provided by a TRNG and some type of on-going re-seeding. +//! - [`ThreadRng`], provided by the [`thread_rng`] function, is a handle to a +//! thread-local CSPRNG with periodic seeding from [`OsRng`]. Because this +//! is local, it is typically much faster than [`OsRng`]. It should be +//! secure, though the paranoid may prefer [`OsRng`]. +//! - [`StdRng`] is a CSPRNG chosen for good performance and trust of security +//! (based on reviews, maturity and usage). The current algorithm is ChaCha12, +//! which is well established and rigorously analysed. +//! [`StdRng`] provides the algorithm used by [`ThreadRng`] but without +//! periodic reseeding. +//! - [`SmallRng`] is an **insecure** PRNG designed to be fast, simple, require +//! little memory, and have good output quality. +//! +//! The algorithms selected for [`StdRng`] and [`SmallRng`] may change in any +//! release and may be platform-dependent, therefore they should be considered +//! **not reproducible**. +//! +//! ## Additional generators +//! +//! **TRNGs**: The [`rdrand`] crate provides an interface to the RDRAND and +//! RDSEED instructions available in modern Intel and AMD CPUs. +//! The [`rand_jitter`] crate provides a user-space implementation of +//! entropy harvesting from CPU timer jitter, but is very slow and has +//! [security issues](https://github.com/rust-random/rand/issues/699). +//! +//! **PRNGs**: Several companion crates are available, providing individual or +//! families of PRNG algorithms. These provide the implementations behind +//! [`StdRng`] and [`SmallRng`] but can also be used directly, indeed *should* +//! be used directly when **reproducibility** matters. +//! Some suggestions are: [`rand_chacha`], [`rand_pcg`], [`rand_xoshiro`]. +//! A full list can be found by searching for crates with the [`rng` tag]. +//! +//! [`Rng`]: crate::Rng +//! [`RngCore`]: crate::RngCore +//! [`CryptoRng`]: crate::CryptoRng +//! [`SeedableRng`]: crate::SeedableRng +//! [`thread_rng`]: crate::thread_rng +//! [`rdrand`]: https://crates.io/crates/rdrand +//! [`rand_jitter`]: https://crates.io/crates/rand_jitter +//! [`rand_chacha`]: https://crates.io/crates/rand_chacha +//! [`rand_pcg`]: https://crates.io/crates/rand_pcg +//! [`rand_xoshiro`]: https://crates.io/crates/rand_xoshiro +//! [`rng` tag]: https://crates.io/keywords/rng + +</span><span class="attribute">#[cfg_attr(doc_cfg, doc(cfg(feature = <span class="string">"std"</span>)))] +#[cfg(feature = <span class="string">"std"</span>)] </span><span class="kw">pub mod </span>adapter; + +<span class="kw">pub mod </span>mock; <span class="comment">// Public so we don't export `StepRng` directly, making it a bit + // more clear it is intended for testing. + +</span><span class="attribute">#[cfg(all(feature = <span class="string">"small_rng"</span>, target_pointer_width = <span class="string">"64"</span>))] +</span><span class="kw">mod </span>xoshiro256plusplus; +<span class="attribute">#[cfg(all(feature = <span class="string">"small_rng"</span>, not(target_pointer_width = <span class="string">"64"</span>)))] +</span><span class="kw">mod </span>xoshiro128plusplus; +<span class="attribute">#[cfg(feature = <span class="string">"small_rng"</span>)] </span><span class="kw">mod </span>small; + +<span class="attribute">#[cfg(feature = <span class="string">"std_rng"</span>)] </span><span class="kw">mod </span>std; +<span class="attribute">#[cfg(all(feature = <span class="string">"std"</span>, feature = <span class="string">"std_rng"</span>))] </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">mod </span>thread; + +<span class="attribute">#[cfg(feature = <span class="string">"small_rng"</span>)] </span><span class="kw">pub use </span><span class="self">self</span>::small::SmallRng; +<span class="attribute">#[cfg(feature = <span class="string">"std_rng"</span>)] </span><span class="kw">pub use </span><span class="self">self</span>::std::StdRng; +<span class="attribute">#[cfg(all(feature = <span class="string">"std"</span>, feature = <span class="string">"std_rng"</span>))] </span><span class="kw">pub use </span><span class="self">self</span>::thread::ThreadRng; + +<span class="attribute">#[cfg_attr(doc_cfg, doc(cfg(feature = <span class="string">"getrandom"</span>)))] +#[cfg(feature = <span class="string">"getrandom"</span>)] </span><span class="kw">pub use </span>rand_core::OsRng; +</code></pre></div> +</section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="rand" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0 (69f9c33d7 2022-12-12) (Arch Linux rust 1:1.66.0-1)" ></div></body></html>
\ No newline at end of file diff --git a/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/rngs/std.rs.html b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/rngs/std.rs.html new file mode 100644 index 0000000..a7d324f --- /dev/null +++ b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/rngs/std.rs.html @@ -0,0 +1,199 @@ +<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/home/pico/.local/share/cargo/registry/src/github.com-1ecc6299db9ec823/rand-0.8.5/src/rngs/std.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>std.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin 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src="../../../main.js"></script><noscript><link rel="stylesheet" href="../../../noscript.css"></noscript><link rel="icon" href="https://www.rust-lang.org/favicon.ico"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../../rand/index.html"> + <img src="https://www.rust-lang.org/logos/rust-logo-128x128-blk.png" alt="logo"></a><form class="search-form"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../../wheel.svg"></a></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> +<span id="2">2</span> +<span id="3">3</span> +<span id="4">4</span> +<span id="5">5</span> +<span id="6">6</span> +<span id="7">7</span> +<span id="8">8</span> +<span id="9">9</span> +<span id="10">10</span> +<span id="11">11</span> +<span id="12">12</span> +<span id="13">13</span> +<span id="14">14</span> +<span id="15">15</span> +<span id="16">16</span> +<span id="17">17</span> +<span id="18">18</span> +<span id="19">19</span> +<span id="20">20</span> +<span id="21">21</span> +<span id="22">22</span> +<span id="23">23</span> +<span id="24">24</span> +<span id="25">25</span> +<span id="26">26</span> +<span id="27">27</span> +<span id="28">28</span> +<span id="29">29</span> +<span id="30">30</span> +<span id="31">31</span> +<span id="32">32</span> +<span id="33">33</span> +<span id="34">34</span> +<span id="35">35</span> +<span id="36">36</span> +<span id="37">37</span> +<span id="38">38</span> +<span id="39">39</span> +<span id="40">40</span> +<span id="41">41</span> +<span id="42">42</span> +<span id="43">43</span> +<span id="44">44</span> +<span id="45">45</span> +<span id="46">46</span> +<span id="47">47</span> +<span id="48">48</span> +<span id="49">49</span> +<span id="50">50</span> +<span id="51">51</span> +<span id="52">52</span> +<span id="53">53</span> +<span id="54">54</span> +<span id="55">55</span> +<span id="56">56</span> +<span id="57">57</span> +<span id="58">58</span> +<span id="59">59</span> +<span id="60">60</span> +<span id="61">61</span> +<span id="62">62</span> +<span id="63">63</span> +<span id="64">64</span> +<span id="65">65</span> +<span id="66">66</span> +<span id="67">67</span> +<span id="68">68</span> +<span id="69">69</span> +<span id="70">70</span> +<span id="71">71</span> +<span id="72">72</span> +<span id="73">73</span> +<span id="74">74</span> +<span id="75">75</span> +<span id="76">76</span> +<span id="77">77</span> +<span id="78">78</span> +<span id="79">79</span> +<span id="80">80</span> +<span id="81">81</span> +<span id="82">82</span> +<span id="83">83</span> +<span id="84">84</span> +<span id="85">85</span> +<span id="86">86</span> +<span id="87">87</span> +<span id="88">88</span> +<span id="89">89</span> +<span id="90">90</span> +<span id="91">91</span> +<span id="92">92</span> +<span id="93">93</span> +<span id="94">94</span> +<span id="95">95</span> +<span id="96">96</span> +<span id="97">97</span> +<span id="98">98</span> +</pre><pre class="rust"><code><span class="comment">// Copyright 2018 Developers of the Rand project. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +</span><span class="doccomment">//! The standard RNG + +</span><span class="kw">use crate</span>::{CryptoRng, Error, RngCore, SeedableRng}; + +<span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">use </span>rand_chacha::ChaCha12Core <span class="kw">as </span>Core; + +<span class="kw">use </span>rand_chacha::ChaCha12Rng <span class="kw">as </span>Rng; + +<span class="doccomment">/// The standard RNG. The PRNG algorithm in `StdRng` is chosen to be efficient +/// on the current platform, to be statistically strong and unpredictable +/// (meaning a cryptographically secure PRNG). +/// +/// The current algorithm used is the ChaCha block cipher with 12 rounds. Please +/// see this relevant [rand issue] for the discussion. This may change as new +/// evidence of cipher security and performance becomes available. +/// +/// The algorithm is deterministic but should not be considered reproducible +/// due to dependence on configuration and possible replacement in future +/// library versions. For a secure reproducible generator, we recommend use of +/// the [rand_chacha] crate directly. +/// +/// [rand_chacha]: https://crates.io/crates/rand_chacha +/// [rand issue]: https://github.com/rust-random/rand/issues/932 +</span><span class="attribute">#[cfg_attr(doc_cfg, doc(cfg(feature = <span class="string">"std_rng"</span>)))] +#[derive(Clone, Debug, PartialEq, Eq)] +</span><span class="kw">pub struct </span>StdRng(Rng); + +<span class="kw">impl </span>RngCore <span class="kw">for </span>StdRng { + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>next_u32(<span class="kw-2">&mut </span><span class="self">self</span>) -> u32 { + <span class="self">self</span>.<span class="number">0</span>.next_u32() + } + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>next_u64(<span class="kw-2">&mut </span><span class="self">self</span>) -> u64 { + <span class="self">self</span>.<span class="number">0</span>.next_u64() + } + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>fill_bytes(<span class="kw-2">&mut </span><span class="self">self</span>, dest: <span class="kw-2">&mut </span>[u8]) { + <span class="self">self</span>.<span class="number">0</span>.fill_bytes(dest); + } + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>try_fill_bytes(<span class="kw-2">&mut </span><span class="self">self</span>, dest: <span class="kw-2">&mut </span>[u8]) -> <span class="prelude-ty">Result</span><(), Error> { + <span class="self">self</span>.<span class="number">0</span>.try_fill_bytes(dest) + } +} + +<span class="kw">impl </span>SeedableRng <span class="kw">for </span>StdRng { + <span class="kw">type </span>Seed = <Rng <span class="kw">as </span>SeedableRng>::Seed; + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>from_seed(seed: <span class="self">Self</span>::Seed) -> <span class="self">Self </span>{ + StdRng(Rng::from_seed(seed)) + } + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>from_rng<R: RngCore>(rng: R) -> <span class="prelude-ty">Result</span><<span class="self">Self</span>, Error> { + Rng::from_rng(rng).map(StdRng) + } +} + +<span class="kw">impl </span>CryptoRng <span class="kw">for </span>StdRng {} + + +<span class="attribute">#[cfg(test)] +</span><span class="kw">mod </span>test { + <span class="kw">use </span><span class="kw">crate</span>::rngs::StdRng; + <span class="kw">use crate</span>::{RngCore, SeedableRng}; + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_stdrng_construction() { + <span class="comment">// Test value-stability of StdRng. This is expected to break any time + // the algorithm is changed. + </span><span class="attribute">#[rustfmt::skip] + </span><span class="kw">let </span>seed = [<span class="number">1</span>,<span class="number">0</span>,<span class="number">0</span>,<span class="number">0</span>, <span class="number">23</span>,<span class="number">0</span>,<span class="number">0</span>,<span class="number">0</span>, <span class="number">200</span>,<span class="number">1</span>,<span class="number">0</span>,<span class="number">0</span>, <span class="number">210</span>,<span class="number">30</span>,<span class="number">0</span>,<span class="number">0</span>, + <span class="number">0</span>,<span class="number">0</span>,<span class="number">0</span>,<span class="number">0</span>, <span class="number">0</span>,<span class="number">0</span>,<span class="number">0</span>,<span class="number">0</span>, <span class="number">0</span>,<span class="number">0</span>,<span class="number">0</span>,<span class="number">0</span>, <span class="number">0</span>,<span class="number">0</span>,<span class="number">0</span>,<span class="number">0</span>]; + + <span class="kw">let </span>target = [<span class="number">10719222850664546238</span>, <span class="number">14064965282130556830</span>]; + + <span class="kw">let </span><span class="kw-2">mut </span>rng0 = StdRng::from_seed(seed); + <span class="kw">let </span>x0 = rng0.next_u64(); + + <span class="kw">let </span><span class="kw-2">mut </span>rng1 = StdRng::from_rng(rng0).unwrap(); + <span class="kw">let </span>x1 = rng1.next_u64(); + + <span class="macro">assert_eq!</span>([x0, x1], target); + } +} +</code></pre></div> +</section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="rand" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0 (69f9c33d7 2022-12-12) (Arch Linux rust 1:1.66.0-1)" ></div></body></html>
\ No newline at end of file diff --git a/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/rngs/thread.rs.html b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/rngs/thread.rs.html new file mode 100644 index 0000000..5243758 --- /dev/null +++ b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/rngs/thread.rs.html @@ -0,0 +1,289 @@ +<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/home/pico/.local/share/cargo/registry/src/github.com-1ecc6299db9ec823/rand-0.8.5/src/rngs/thread.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>thread.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin 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src="../../../wheel.svg"></a></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> +<span id="2">2</span> +<span id="3">3</span> +<span id="4">4</span> +<span id="5">5</span> +<span id="6">6</span> +<span id="7">7</span> +<span id="8">8</span> +<span id="9">9</span> +<span id="10">10</span> +<span id="11">11</span> +<span id="12">12</span> +<span id="13">13</span> +<span id="14">14</span> +<span id="15">15</span> +<span id="16">16</span> +<span id="17">17</span> +<span id="18">18</span> +<span id="19">19</span> +<span id="20">20</span> +<span id="21">21</span> +<span id="22">22</span> +<span id="23">23</span> +<span id="24">24</span> +<span id="25">25</span> +<span id="26">26</span> +<span id="27">27</span> +<span id="28">28</span> +<span id="29">29</span> +<span id="30">30</span> +<span id="31">31</span> +<span id="32">32</span> +<span id="33">33</span> +<span id="34">34</span> +<span 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+<span id="114">114</span> +<span id="115">115</span> +<span id="116">116</span> +<span id="117">117</span> +<span id="118">118</span> +<span id="119">119</span> +<span id="120">120</span> +<span id="121">121</span> +<span id="122">122</span> +<span id="123">123</span> +<span id="124">124</span> +<span id="125">125</span> +<span id="126">126</span> +<span id="127">127</span> +<span id="128">128</span> +<span id="129">129</span> +<span id="130">130</span> +<span id="131">131</span> +<span id="132">132</span> +<span id="133">133</span> +<span id="134">134</span> +<span id="135">135</span> +<span id="136">136</span> +<span id="137">137</span> +<span id="138">138</span> +<span id="139">139</span> +<span id="140">140</span> +<span id="141">141</span> +<span id="142">142</span> +<span id="143">143</span> +</pre><pre class="rust"><code><span class="comment">// Copyright 2018 Developers of the Rand project. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +</span><span class="doccomment">//! Thread-local random number generator + +</span><span class="kw">use </span>core::cell::UnsafeCell; +<span class="kw">use </span>std::rc::Rc; +<span class="kw">use </span>std::thread_local; + +<span class="kw">use </span><span class="kw">super</span>::std::Core; +<span class="kw">use </span><span class="kw">crate</span>::rngs::adapter::ReseedingRng; +<span class="kw">use </span><span class="kw">crate</span>::rngs::OsRng; +<span class="kw">use crate</span>::{CryptoRng, Error, RngCore, SeedableRng}; + +<span class="comment">// Rationale for using `UnsafeCell` in `ThreadRng`: +// +// Previously we used a `RefCell`, with an overhead of ~15%. There will only +// ever be one mutable reference to the interior of the `UnsafeCell`, because +// we only have such a reference inside `next_u32`, `next_u64`, etc. Within a +// single thread (which is the definition of `ThreadRng`), there will only ever +// be one of these methods active at a time. +// +// A possible scenario where there could be multiple mutable references is if +// `ThreadRng` is used inside `next_u32` and co. But the implementation is +// completely under our control. We just have to ensure none of them use +// `ThreadRng` internally, which is nonsensical anyway. We should also never run +// `ThreadRng` in destructors of its implementation, which is also nonsensical. + + +// Number of generated bytes after which to reseed `ThreadRng`. +// According to benchmarks, reseeding has a noticeable impact with thresholds +// of 32 kB and less. We choose 64 kB to avoid significant overhead. +</span><span class="kw">const </span>THREAD_RNG_RESEED_THRESHOLD: u64 = <span class="number">1024 </span>* <span class="number">64</span>; + +<span class="doccomment">/// A reference to the thread-local generator +/// +/// An instance can be obtained via [`thread_rng`] or via `ThreadRng::default()`. +/// This handle is safe to use everywhere (including thread-local destructors), +/// though it is recommended not to use inside a fork handler. +/// The handle cannot be passed between threads (is not `Send` or `Sync`). +/// +/// `ThreadRng` uses the same PRNG as [`StdRng`] for security and performance +/// and is automatically seeded from [`OsRng`]. +/// +/// Unlike `StdRng`, `ThreadRng` uses the [`ReseedingRng`] wrapper to reseed +/// the PRNG from fresh entropy every 64 kiB of random data as well as after a +/// fork on Unix (though not quite immediately; see documentation of +/// [`ReseedingRng`]). +/// Note that the reseeding is done as an extra precaution against side-channel +/// attacks and mis-use (e.g. if somehow weak entropy were supplied initially). +/// The PRNG algorithms used are assumed to be secure. +/// +/// [`ReseedingRng`]: crate::rngs::adapter::ReseedingRng +/// [`StdRng`]: crate::rngs::StdRng +</span><span class="attribute">#[cfg_attr(doc_cfg, doc(cfg(all(feature = <span class="string">"std"</span>, feature = <span class="string">"std_rng"</span>))))] +#[derive(Clone, Debug)] +</span><span class="kw">pub struct </span>ThreadRng { + <span class="comment">// Rc is explicitly !Send and !Sync + </span>rng: Rc<UnsafeCell<ReseedingRng<Core, OsRng>>>, +} + +<span class="macro">thread_local!</span>( + <span class="comment">// We require Rc<..> to avoid premature freeing when thread_rng is used + // within thread-local destructors. See #968. + </span><span class="kw">static </span>THREAD_RNG_KEY: Rc<UnsafeCell<ReseedingRng<Core, OsRng>>> = { + <span class="kw">let </span>r = Core::from_rng(OsRng).unwrap_or_else(|err| + <span class="macro">panic!</span>(<span class="string">"could not initialize thread_rng: {}"</span>, err)); + <span class="kw">let </span>rng = ReseedingRng::new(r, + THREAD_RNG_RESEED_THRESHOLD, + OsRng); + Rc::new(UnsafeCell::new(rng)) + } +); + +<span class="doccomment">/// Retrieve the lazily-initialized thread-local random number generator, +/// seeded by the system. Intended to be used in method chaining style, +/// e.g. `thread_rng().gen::<i32>()`, or cached locally, e.g. +/// `let mut rng = thread_rng();`. Invoked by the `Default` trait, making +/// `ThreadRng::default()` equivalent. +/// +/// For more information see [`ThreadRng`]. +</span><span class="attribute">#[cfg_attr(doc_cfg, doc(cfg(all(feature = <span class="string">"std"</span>, feature = <span class="string">"std_rng"</span>))))] +</span><span class="kw">pub fn </span>thread_rng() -> ThreadRng { + <span class="kw">let </span>rng = THREAD_RNG_KEY.with(|t| t.clone()); + ThreadRng { rng } +} + +<span class="kw">impl </span>Default <span class="kw">for </span>ThreadRng { + <span class="kw">fn </span>default() -> ThreadRng { + <span class="kw">crate</span>::prelude::thread_rng() + } +} + +<span class="kw">impl </span>RngCore <span class="kw">for </span>ThreadRng { + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>next_u32(<span class="kw-2">&mut </span><span class="self">self</span>) -> u32 { + <span class="comment">// SAFETY: We must make sure to stop using `rng` before anyone else + // creates another mutable reference + </span><span class="kw">let </span>rng = <span class="kw">unsafe </span>{ <span class="kw-2">&mut *</span><span class="self">self</span>.rng.get() }; + rng.next_u32() + } + + <span class="attribute">#[inline(always)] + </span><span class="kw">fn </span>next_u64(<span class="kw-2">&mut </span><span class="self">self</span>) -> u64 { + <span class="comment">// SAFETY: We must make sure to stop using `rng` before anyone else + // creates another mutable reference + </span><span class="kw">let </span>rng = <span class="kw">unsafe </span>{ <span class="kw-2">&mut *</span><span class="self">self</span>.rng.get() }; + rng.next_u64() + } + + <span class="kw">fn </span>fill_bytes(<span class="kw-2">&mut </span><span class="self">self</span>, dest: <span class="kw-2">&mut </span>[u8]) { + <span class="comment">// SAFETY: We must make sure to stop using `rng` before anyone else + // creates another mutable reference + </span><span class="kw">let </span>rng = <span class="kw">unsafe </span>{ <span class="kw-2">&mut *</span><span class="self">self</span>.rng.get() }; + rng.fill_bytes(dest) + } + + <span class="kw">fn </span>try_fill_bytes(<span class="kw-2">&mut </span><span class="self">self</span>, dest: <span class="kw-2">&mut </span>[u8]) -> <span class="prelude-ty">Result</span><(), Error> { + <span class="comment">// SAFETY: We must make sure to stop using `rng` before anyone else + // creates another mutable reference + </span><span class="kw">let </span>rng = <span class="kw">unsafe </span>{ <span class="kw-2">&mut *</span><span class="self">self</span>.rng.get() }; + rng.try_fill_bytes(dest) + } +} + +<span class="kw">impl </span>CryptoRng <span class="kw">for </span>ThreadRng {} + + +<span class="attribute">#[cfg(test)] +</span><span class="kw">mod </span>test { + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_thread_rng() { + <span class="kw">use </span><span class="kw">crate</span>::Rng; + <span class="kw">let </span><span class="kw-2">mut </span>r = <span class="kw">crate</span>::thread_rng(); + r.gen::<i32>(); + <span class="macro">assert_eq!</span>(r.gen_range(<span class="number">0</span>..<span class="number">1</span>), <span class="number">0</span>); + } +} +</code></pre></div> +</section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="rand" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0 (69f9c33d7 2022-12-12) (Arch Linux rust 1:1.66.0-1)" ></div></body></html>
\ No newline at end of file diff --git a/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/seq/index.rs.html b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/seq/index.rs.html new file mode 100644 index 0000000..9f59f7f --- /dev/null +++ b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/seq/index.rs.html @@ -0,0 +1,1359 @@ +<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/home/pico/.local/share/cargo/registry/src/github.com-1ecc6299db9ec823/rand-0.8.5/src/seq/index.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>index.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin 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src="../../../wheel.svg"></a></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> +<span id="2">2</span> +<span id="3">3</span> +<span id="4">4</span> +<span id="5">5</span> +<span id="6">6</span> +<span id="7">7</span> +<span id="8">8</span> +<span id="9">9</span> +<span id="10">10</span> +<span id="11">11</span> +<span id="12">12</span> +<span id="13">13</span> +<span id="14">14</span> +<span id="15">15</span> +<span id="16">16</span> +<span id="17">17</span> +<span id="18">18</span> +<span id="19">19</span> +<span id="20">20</span> +<span id="21">21</span> +<span id="22">22</span> +<span id="23">23</span> +<span id="24">24</span> +<span id="25">25</span> +<span id="26">26</span> +<span id="27">27</span> +<span id="28">28</span> +<span id="29">29</span> +<span id="30">30</span> +<span id="31">31</span> +<span id="32">32</span> +<span id="33">33</span> +<span id="34">34</span> +<span 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+<span id="447">447</span> +<span id="448">448</span> +<span id="449">449</span> +<span id="450">450</span> +<span id="451">451</span> +<span id="452">452</span> +<span id="453">453</span> +<span id="454">454</span> +<span id="455">455</span> +<span id="456">456</span> +<span id="457">457</span> +<span id="458">458</span> +<span id="459">459</span> +<span id="460">460</span> +<span id="461">461</span> +<span id="462">462</span> +<span id="463">463</span> +<span id="464">464</span> +<span id="465">465</span> +<span id="466">466</span> +<span id="467">467</span> +<span id="468">468</span> +<span id="469">469</span> +<span id="470">470</span> +<span id="471">471</span> +<span id="472">472</span> +<span id="473">473</span> +<span id="474">474</span> +<span id="475">475</span> +<span id="476">476</span> +<span id="477">477</span> +<span id="478">478</span> +<span id="479">479</span> +<span id="480">480</span> +<span id="481">481</span> +<span id="482">482</span> +<span id="483">483</span> +<span id="484">484</span> +<span id="485">485</span> +<span id="486">486</span> +<span id="487">487</span> +<span id="488">488</span> +<span id="489">489</span> +<span id="490">490</span> +<span id="491">491</span> +<span id="492">492</span> +<span id="493">493</span> +<span id="494">494</span> +<span id="495">495</span> +<span id="496">496</span> +<span id="497">497</span> +<span id="498">498</span> +<span id="499">499</span> +<span id="500">500</span> +<span id="501">501</span> +<span id="502">502</span> +<span id="503">503</span> +<span id="504">504</span> +<span id="505">505</span> +<span id="506">506</span> +<span id="507">507</span> +<span id="508">508</span> +<span id="509">509</span> +<span id="510">510</span> +<span id="511">511</span> +<span id="512">512</span> +<span id="513">513</span> +<span id="514">514</span> +<span id="515">515</span> +<span id="516">516</span> +<span id="517">517</span> +<span id="518">518</span> +<span id="519">519</span> +<span id="520">520</span> +<span id="521">521</span> +<span id="522">522</span> +<span id="523">523</span> +<span id="524">524</span> +<span id="525">525</span> +<span id="526">526</span> +<span id="527">527</span> +<span id="528">528</span> +<span id="529">529</span> +<span id="530">530</span> +<span id="531">531</span> +<span id="532">532</span> +<span id="533">533</span> +<span id="534">534</span> +<span id="535">535</span> +<span id="536">536</span> +<span id="537">537</span> +<span id="538">538</span> +<span id="539">539</span> +<span id="540">540</span> +<span id="541">541</span> +<span id="542">542</span> +<span id="543">543</span> +<span id="544">544</span> +<span id="545">545</span> +<span id="546">546</span> +<span id="547">547</span> +<span id="548">548</span> +<span id="549">549</span> +<span id="550">550</span> +<span id="551">551</span> +<span id="552">552</span> +<span id="553">553</span> +<span id="554">554</span> +<span id="555">555</span> +<span id="556">556</span> +<span id="557">557</span> +<span id="558">558</span> +<span id="559">559</span> +<span id="560">560</span> +<span id="561">561</span> +<span id="562">562</span> +<span id="563">563</span> +<span id="564">564</span> +<span id="565">565</span> +<span id="566">566</span> +<span id="567">567</span> +<span id="568">568</span> +<span id="569">569</span> +<span id="570">570</span> +<span id="571">571</span> +<span id="572">572</span> +<span id="573">573</span> +<span id="574">574</span> +<span id="575">575</span> +<span id="576">576</span> +<span id="577">577</span> +<span id="578">578</span> +<span id="579">579</span> +<span id="580">580</span> +<span id="581">581</span> +<span id="582">582</span> +<span id="583">583</span> +<span id="584">584</span> +<span id="585">585</span> +<span id="586">586</span> +<span id="587">587</span> +<span id="588">588</span> +<span id="589">589</span> +<span id="590">590</span> +<span id="591">591</span> +<span id="592">592</span> +<span id="593">593</span> +<span id="594">594</span> +<span id="595">595</span> +<span id="596">596</span> +<span id="597">597</span> +<span id="598">598</span> +<span id="599">599</span> +<span id="600">600</span> +<span id="601">601</span> +<span id="602">602</span> +<span id="603">603</span> +<span id="604">604</span> +<span id="605">605</span> +<span id="606">606</span> +<span id="607">607</span> +<span id="608">608</span> +<span id="609">609</span> +<span id="610">610</span> +<span id="611">611</span> +<span id="612">612</span> +<span id="613">613</span> +<span id="614">614</span> +<span id="615">615</span> +<span id="616">616</span> +<span id="617">617</span> +<span id="618">618</span> +<span id="619">619</span> +<span id="620">620</span> +<span id="621">621</span> +<span id="622">622</span> +<span id="623">623</span> +<span id="624">624</span> +<span id="625">625</span> +<span id="626">626</span> +<span id="627">627</span> +<span id="628">628</span> +<span id="629">629</span> +<span id="630">630</span> +<span id="631">631</span> +<span id="632">632</span> +<span id="633">633</span> +<span id="634">634</span> +<span id="635">635</span> +<span id="636">636</span> +<span id="637">637</span> +<span id="638">638</span> +<span id="639">639</span> +<span id="640">640</span> +<span id="641">641</span> +<span id="642">642</span> +<span id="643">643</span> +<span id="644">644</span> +<span id="645">645</span> +<span id="646">646</span> +<span id="647">647</span> +<span id="648">648</span> +<span id="649">649</span> +<span id="650">650</span> +<span id="651">651</span> +<span id="652">652</span> +<span id="653">653</span> +<span id="654">654</span> +<span id="655">655</span> +<span id="656">656</span> +<span id="657">657</span> +<span id="658">658</span> +<span id="659">659</span> +<span id="660">660</span> +<span id="661">661</span> +<span id="662">662</span> +<span id="663">663</span> +<span id="664">664</span> +<span id="665">665</span> +<span id="666">666</span> +<span id="667">667</span> +<span id="668">668</span> +<span id="669">669</span> +<span id="670">670</span> +<span id="671">671</span> +<span id="672">672</span> +<span id="673">673</span> +<span id="674">674</span> +<span id="675">675</span> +<span id="676">676</span> +<span id="677">677</span> +<span id="678">678</span> +</pre><pre class="rust"><code><span class="comment">// Copyright 2018 Developers of the Rand project. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +</span><span class="doccomment">//! Low-level API for sampling indices + +</span><span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] </span><span class="kw">use </span>core::slice; + +<span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] </span><span class="kw">use </span>alloc::vec::{<span class="self">self</span>, Vec}; +<span class="comment">// BTreeMap is not as fast in tests, but better than nothing. +</span><span class="attribute">#[cfg(all(feature = <span class="string">"alloc"</span>, not(feature = <span class="string">"std"</span>)))] +</span><span class="kw">use </span>alloc::collections::BTreeSet; +<span class="attribute">#[cfg(feature = <span class="string">"std"</span>)] </span><span class="kw">use </span>std::collections::HashSet; + +<span class="attribute">#[cfg(feature = <span class="string">"std"</span>)] +</span><span class="kw">use </span><span class="kw">crate</span>::distributions::WeightedError; + +<span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] +</span><span class="kw">use crate</span>::{Rng, distributions::{uniform::SampleUniform, Distribution, Uniform}}; + +<span class="attribute">#[cfg(feature = <span class="string">"serde1"</span>)] +</span><span class="kw">use </span>serde::{Serialize, Deserialize}; + +<span class="doccomment">/// A vector of indices. +/// +/// Multiple internal representations are possible. +</span><span class="attribute">#[derive(Clone, Debug)] +#[cfg_attr(feature = <span class="string">"serde1"</span>, derive(Serialize, Deserialize))] +</span><span class="kw">pub enum </span>IndexVec { + <span class="attribute">#[doc(hidden)] + </span>U32(Vec<u32>), + <span class="attribute">#[doc(hidden)] + </span>USize(Vec<usize>), +} + +<span class="kw">impl </span>IndexVec { + <span class="doccomment">/// Returns the number of indices + </span><span class="attribute">#[inline] + </span><span class="kw">pub fn </span>len(<span class="kw-2">&</span><span class="self">self</span>) -> usize { + <span class="kw">match </span><span class="kw-2">*</span><span class="self">self </span>{ + IndexVec::U32(<span class="kw-2">ref </span>v) => v.len(), + IndexVec::USize(<span class="kw-2">ref </span>v) => v.len(), + } + } + + <span class="doccomment">/// Returns `true` if the length is 0. + </span><span class="attribute">#[inline] + </span><span class="kw">pub fn </span>is_empty(<span class="kw-2">&</span><span class="self">self</span>) -> bool { + <span class="kw">match </span><span class="kw-2">*</span><span class="self">self </span>{ + IndexVec::U32(<span class="kw-2">ref </span>v) => v.is_empty(), + IndexVec::USize(<span class="kw-2">ref </span>v) => v.is_empty(), + } + } + + <span class="doccomment">/// Return the value at the given `index`. + /// + /// (Note: we cannot implement [`std::ops::Index`] because of lifetime + /// restrictions.) + </span><span class="attribute">#[inline] + </span><span class="kw">pub fn </span>index(<span class="kw-2">&</span><span class="self">self</span>, index: usize) -> usize { + <span class="kw">match </span><span class="kw-2">*</span><span class="self">self </span>{ + IndexVec::U32(<span class="kw-2">ref </span>v) => v[index] <span class="kw">as </span>usize, + IndexVec::USize(<span class="kw-2">ref </span>v) => v[index], + } + } + + <span class="doccomment">/// Return result as a `Vec<usize>`. Conversion may or may not be trivial. + </span><span class="attribute">#[inline] + </span><span class="kw">pub fn </span>into_vec(<span class="self">self</span>) -> Vec<usize> { + <span class="kw">match </span><span class="self">self </span>{ + IndexVec::U32(v) => v.into_iter().map(|i| i <span class="kw">as </span>usize).collect(), + IndexVec::USize(v) => v, + } + } + + <span class="doccomment">/// Iterate over the indices as a sequence of `usize` values + </span><span class="attribute">#[inline] + </span><span class="kw">pub fn </span>iter(<span class="kw-2">&</span><span class="self">self</span>) -> IndexVecIter<<span class="lifetime">'_</span>> { + <span class="kw">match </span><span class="kw-2">*</span><span class="self">self </span>{ + IndexVec::U32(<span class="kw-2">ref </span>v) => IndexVecIter::U32(v.iter()), + IndexVec::USize(<span class="kw-2">ref </span>v) => IndexVecIter::USize(v.iter()), + } + } +} + +<span class="kw">impl </span>IntoIterator <span class="kw">for </span>IndexVec { + <span class="kw">type </span>Item = usize; + <span class="kw">type </span>IntoIter = IndexVecIntoIter; + + <span class="doccomment">/// Convert into an iterator over the indices as a sequence of `usize` values + </span><span class="attribute">#[inline] + </span><span class="kw">fn </span>into_iter(<span class="self">self</span>) -> IndexVecIntoIter { + <span class="kw">match </span><span class="self">self </span>{ + IndexVec::U32(v) => IndexVecIntoIter::U32(v.into_iter()), + IndexVec::USize(v) => IndexVecIntoIter::USize(v.into_iter()), + } + } +} + +<span class="kw">impl </span>PartialEq <span class="kw">for </span>IndexVec { + <span class="kw">fn </span>eq(<span class="kw-2">&</span><span class="self">self</span>, other: <span class="kw-2">&</span>IndexVec) -> bool { + <span class="kw">use </span><span class="self">self</span>::IndexVec::<span class="kw-2">*</span>; + <span class="kw">match </span>(<span class="self">self</span>, other) { + (<span class="kw-2">&</span>U32(<span class="kw-2">ref </span>v1), <span class="kw-2">&</span>U32(<span class="kw-2">ref </span>v2)) => v1 == v2, + (<span class="kw-2">&</span>USize(<span class="kw-2">ref </span>v1), <span class="kw-2">&</span>USize(<span class="kw-2">ref </span>v2)) => v1 == v2, + (<span class="kw-2">&</span>U32(<span class="kw-2">ref </span>v1), <span class="kw-2">&</span>USize(<span class="kw-2">ref </span>v2)) => { + (v1.len() == v2.len()) && (v1.iter().zip(v2.iter()).all(|(x, y)| <span class="kw-2">*</span>x <span class="kw">as </span>usize == <span class="kw-2">*</span>y)) + } + (<span class="kw-2">&</span>USize(<span class="kw-2">ref </span>v1), <span class="kw-2">&</span>U32(<span class="kw-2">ref </span>v2)) => { + (v1.len() == v2.len()) && (v1.iter().zip(v2.iter()).all(|(x, y)| <span class="kw-2">*</span>x == <span class="kw-2">*</span>y <span class="kw">as </span>usize)) + } + } + } +} + +<span class="kw">impl </span>From<Vec<u32>> <span class="kw">for </span>IndexVec { + <span class="attribute">#[inline] + </span><span class="kw">fn </span>from(v: Vec<u32>) -> <span class="self">Self </span>{ + IndexVec::U32(v) + } +} + +<span class="kw">impl </span>From<Vec<usize>> <span class="kw">for </span>IndexVec { + <span class="attribute">#[inline] + </span><span class="kw">fn </span>from(v: Vec<usize>) -> <span class="self">Self </span>{ + IndexVec::USize(v) + } +} + +<span class="doccomment">/// Return type of `IndexVec::iter`. +</span><span class="attribute">#[derive(Debug)] +</span><span class="kw">pub enum </span>IndexVecIter<<span class="lifetime">'a</span>> { + <span class="attribute">#[doc(hidden)] + </span>U32(slice::Iter<<span class="lifetime">'a</span>, u32>), + <span class="attribute">#[doc(hidden)] + </span>USize(slice::Iter<<span class="lifetime">'a</span>, usize>), +} + +<span class="kw">impl</span><<span class="lifetime">'a</span>> Iterator <span class="kw">for </span>IndexVecIter<<span class="lifetime">'a</span>> { + <span class="kw">type </span>Item = usize; + + <span class="attribute">#[inline] + </span><span class="kw">fn </span>next(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><usize> { + <span class="kw">use </span><span class="self">self</span>::IndexVecIter::<span class="kw-2">*</span>; + <span class="kw">match </span><span class="kw-2">*</span><span class="self">self </span>{ + U32(<span class="kw-2">ref mut </span>iter) => iter.next().map(|i| <span class="kw-2">*</span>i <span class="kw">as </span>usize), + USize(<span class="kw-2">ref mut </span>iter) => iter.next().cloned(), + } + } + + <span class="attribute">#[inline] + </span><span class="kw">fn </span>size_hint(<span class="kw-2">&</span><span class="self">self</span>) -> (usize, <span class="prelude-ty">Option</span><usize>) { + <span class="kw">match </span><span class="kw-2">*</span><span class="self">self </span>{ + IndexVecIter::U32(<span class="kw-2">ref </span>v) => v.size_hint(), + IndexVecIter::USize(<span class="kw-2">ref </span>v) => v.size_hint(), + } + } +} + +<span class="kw">impl</span><<span class="lifetime">'a</span>> ExactSizeIterator <span class="kw">for </span>IndexVecIter<<span class="lifetime">'a</span>> {} + +<span class="doccomment">/// Return type of `IndexVec::into_iter`. +</span><span class="attribute">#[derive(Clone, Debug)] +</span><span class="kw">pub enum </span>IndexVecIntoIter { + <span class="attribute">#[doc(hidden)] + </span>U32(vec::IntoIter<u32>), + <span class="attribute">#[doc(hidden)] + </span>USize(vec::IntoIter<usize>), +} + +<span class="kw">impl </span>Iterator <span class="kw">for </span>IndexVecIntoIter { + <span class="kw">type </span>Item = usize; + + <span class="attribute">#[inline] + </span><span class="kw">fn </span>next(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>::Item> { + <span class="kw">use </span><span class="self">self</span>::IndexVecIntoIter::<span class="kw-2">*</span>; + <span class="kw">match </span><span class="kw-2">*</span><span class="self">self </span>{ + U32(<span class="kw-2">ref mut </span>v) => v.next().map(|i| i <span class="kw">as </span>usize), + USize(<span class="kw-2">ref mut </span>v) => v.next(), + } + } + + <span class="attribute">#[inline] + </span><span class="kw">fn </span>size_hint(<span class="kw-2">&</span><span class="self">self</span>) -> (usize, <span class="prelude-ty">Option</span><usize>) { + <span class="kw">use </span><span class="self">self</span>::IndexVecIntoIter::<span class="kw-2">*</span>; + <span class="kw">match </span><span class="kw-2">*</span><span class="self">self </span>{ + U32(<span class="kw-2">ref </span>v) => v.size_hint(), + USize(<span class="kw-2">ref </span>v) => v.size_hint(), + } + } +} + +<span class="kw">impl </span>ExactSizeIterator <span class="kw">for </span>IndexVecIntoIter {} + + +<span class="doccomment">/// Randomly sample exactly `amount` distinct indices from `0..length`, and +/// return them in random order (fully shuffled). +/// +/// This method is used internally by the slice sampling methods, but it can +/// sometimes be useful to have the indices themselves so this is provided as +/// an alternative. +/// +/// The implementation used is not specified; we automatically select the +/// fastest available algorithm for the `length` and `amount` parameters +/// (based on detailed profiling on an Intel Haswell CPU). Roughly speaking, +/// complexity is `O(amount)`, except that when `amount` is small, performance +/// is closer to `O(amount^2)`, and when `length` is close to `amount` then +/// `O(length)`. +/// +/// Note that performance is significantly better over `u32` indices than over +/// `u64` indices. Because of this we hide the underlying type behind an +/// abstraction, `IndexVec`. +/// +/// If an allocation-free `no_std` function is required, it is suggested +/// to adapt the internal `sample_floyd` implementation. +/// +/// Panics if `amount > length`. +</span><span class="kw">pub fn </span>sample<R>(rng: <span class="kw-2">&mut </span>R, length: usize, amount: usize) -> IndexVec +<span class="kw">where </span>R: Rng + <span class="question-mark">?</span>Sized { + <span class="kw">if </span>amount > length { + <span class="macro">panic!</span>(<span class="string">"`amount` of samples must be less than or equal to `length`"</span>); + } + <span class="kw">if </span>length > (::core::u32::MAX <span class="kw">as </span>usize) { + <span class="comment">// We never want to use inplace here, but could use floyd's alg + // Lazy version: always use the cache alg. + </span><span class="kw">return </span>sample_rejection(rng, length, amount); + } + <span class="kw">let </span>amount = amount <span class="kw">as </span>u32; + <span class="kw">let </span>length = length <span class="kw">as </span>u32; + + <span class="comment">// Choice of algorithm here depends on both length and amount. See: + // https://github.com/rust-random/rand/pull/479 + // We do some calculations with f32. Accuracy is not very important. + + </span><span class="kw">if </span>amount < <span class="number">163 </span>{ + <span class="kw">const </span>C: [[f32; <span class="number">2</span>]; <span class="number">2</span>] = [[<span class="number">1.6</span>, <span class="number">8.0 </span>/ <span class="number">45.0</span>], [<span class="number">10.0</span>, <span class="number">70.0 </span>/ <span class="number">9.0</span>]]; + <span class="kw">let </span>j = <span class="kw">if </span>length < <span class="number">500_000 </span>{ <span class="number">0 </span>} <span class="kw">else </span>{ <span class="number">1 </span>}; + <span class="kw">let </span>amount_fp = amount <span class="kw">as </span>f32; + <span class="kw">let </span>m4 = C[<span class="number">0</span>][j] * amount_fp; + <span class="comment">// Short-cut: when amount < 12, floyd's is always faster + </span><span class="kw">if </span>amount > <span class="number">11 </span>&& (length <span class="kw">as </span>f32) < (C[<span class="number">1</span>][j] + m4) * amount_fp { + sample_inplace(rng, length, amount) + } <span class="kw">else </span>{ + sample_floyd(rng, length, amount) + } + } <span class="kw">else </span>{ + <span class="kw">const </span>C: [f32; <span class="number">2</span>] = [<span class="number">270.0</span>, <span class="number">330.0 </span>/ <span class="number">9.0</span>]; + <span class="kw">let </span>j = <span class="kw">if </span>length < <span class="number">500_000 </span>{ <span class="number">0 </span>} <span class="kw">else </span>{ <span class="number">1 </span>}; + <span class="kw">if </span>(length <span class="kw">as </span>f32) < C[j] * (amount <span class="kw">as </span>f32) { + sample_inplace(rng, length, amount) + } <span class="kw">else </span>{ + sample_rejection(rng, length, amount) + } + } +} + +<span class="doccomment">/// Randomly sample exactly `amount` distinct indices from `0..length`, and +/// return them in an arbitrary order (there is no guarantee of shuffling or +/// ordering). The weights are to be provided by the input function `weights`, +/// which will be called once for each index. +/// +/// This method is used internally by the slice sampling methods, but it can +/// sometimes be useful to have the indices themselves so this is provided as +/// an alternative. +/// +/// This implementation uses `O(length + amount)` space and `O(length)` time +/// if the "nightly" feature is enabled, or `O(length)` space and +/// `O(length + amount * log length)` time otherwise. +/// +/// Panics if `amount > length`. +</span><span class="attribute">#[cfg(feature = <span class="string">"std"</span>)] +#[cfg_attr(doc_cfg, doc(cfg(feature = <span class="string">"std"</span>)))] +</span><span class="kw">pub fn </span>sample_weighted<R, F, X>( + rng: <span class="kw-2">&mut </span>R, length: usize, weight: F, amount: usize, +) -> <span class="prelude-ty">Result</span><IndexVec, WeightedError> +<span class="kw">where + </span>R: Rng + <span class="question-mark">?</span>Sized, + F: Fn(usize) -> X, + X: Into<f64>, +{ + <span class="kw">if </span>length > (core::u32::MAX <span class="kw">as </span>usize) { + sample_efraimidis_spirakis(rng, length, weight, amount) + } <span class="kw">else </span>{ + <span class="macro">assert!</span>(amount <= core::u32::MAX <span class="kw">as </span>usize); + <span class="kw">let </span>amount = amount <span class="kw">as </span>u32; + <span class="kw">let </span>length = length <span class="kw">as </span>u32; + sample_efraimidis_spirakis(rng, length, weight, amount) + } +} + + +<span class="doccomment">/// Randomly sample exactly `amount` distinct indices from `0..length`, and +/// return them in an arbitrary order (there is no guarantee of shuffling or +/// ordering). The weights are to be provided by the input function `weights`, +/// which will be called once for each index. +/// +/// This implementation uses the algorithm described by Efraimidis and Spirakis +/// in this paper: https://doi.org/10.1016/j.ipl.2005.11.003 +/// It uses `O(length + amount)` space and `O(length)` time if the +/// "nightly" feature is enabled, or `O(length)` space and `O(length +/// + amount * log length)` time otherwise. +/// +/// Panics if `amount > length`. +</span><span class="attribute">#[cfg(feature = <span class="string">"std"</span>)] +</span><span class="kw">fn </span>sample_efraimidis_spirakis<R, F, X, N>( + rng: <span class="kw-2">&mut </span>R, length: N, weight: F, amount: N, +) -> <span class="prelude-ty">Result</span><IndexVec, WeightedError> +<span class="kw">where + </span>R: Rng + <span class="question-mark">?</span>Sized, + F: Fn(usize) -> X, + X: Into<f64>, + N: UInt, + IndexVec: From<Vec<N>>, +{ + <span class="kw">if </span>amount == N::zero() { + <span class="kw">return </span><span class="prelude-val">Ok</span>(IndexVec::U32(Vec::new())); + } + + <span class="kw">if </span>amount > length { + <span class="macro">panic!</span>(<span class="string">"`amount` of samples must be less than or equal to `length`"</span>); + } + + <span class="kw">struct </span>Element<N> { + index: N, + key: f64, + } + <span class="kw">impl</span><N> PartialOrd <span class="kw">for </span>Element<N> { + <span class="kw">fn </span>partial_cmp(<span class="kw-2">&</span><span class="self">self</span>, other: <span class="kw-2">&</span><span class="self">Self</span>) -> <span class="prelude-ty">Option</span><core::cmp::Ordering> { + <span class="self">self</span>.key.partial_cmp(<span class="kw-2">&</span>other.key) + } + } + <span class="kw">impl</span><N> Ord <span class="kw">for </span>Element<N> { + <span class="kw">fn </span>cmp(<span class="kw-2">&</span><span class="self">self</span>, other: <span class="kw-2">&</span><span class="self">Self</span>) -> core::cmp::Ordering { + <span class="comment">// partial_cmp will always produce a value, + // because we check that the weights are not nan + </span><span class="self">self</span>.partial_cmp(other).unwrap() + } + } + <span class="kw">impl</span><N> PartialEq <span class="kw">for </span>Element<N> { + <span class="kw">fn </span>eq(<span class="kw-2">&</span><span class="self">self</span>, other: <span class="kw-2">&</span><span class="self">Self</span>) -> bool { + <span class="self">self</span>.key == other.key + } + } + <span class="kw">impl</span><N> Eq <span class="kw">for </span>Element<N> {} + + <span class="attribute">#[cfg(feature = <span class="string">"nightly"</span>)] + </span>{ + <span class="kw">let </span><span class="kw-2">mut </span>candidates = Vec::with_capacity(length.as_usize()); + <span class="kw">let </span><span class="kw-2">mut </span>index = N::zero(); + <span class="kw">while </span>index < length { + <span class="kw">let </span>weight = weight(index.as_usize()).into(); + <span class="kw">if </span>!(weight >= <span class="number">0.</span>) { + <span class="kw">return </span><span class="prelude-val">Err</span>(WeightedError::InvalidWeight); + } + + <span class="kw">let </span>key = rng.gen::<f64>().powf(<span class="number">1.0 </span>/ weight); + candidates.push(Element { index, key }); + + index += N::one(); + } + + <span class="comment">// Partially sort the array to find the `amount` elements with the greatest + // keys. Do this by using `select_nth_unstable` to put the elements with + // the *smallest* keys at the beginning of the list in `O(n)` time, which + // provides equivalent information about the elements with the *greatest* keys. + </span><span class="kw">let </span>(<span class="kw">_</span>, mid, greater) + = candidates.select_nth_unstable(length.as_usize() - amount.as_usize()); + + <span class="kw">let </span><span class="kw-2">mut </span>result: Vec<N> = Vec::with_capacity(amount.as_usize()); + result.push(mid.index); + <span class="kw">for </span>element <span class="kw">in </span>greater { + result.push(element.index); + } + <span class="prelude-val">Ok</span>(IndexVec::from(result)) + } + + <span class="attribute">#[cfg(not(feature = <span class="string">"nightly"</span>))] + </span>{ + <span class="kw">use </span>alloc::collections::BinaryHeap; + + <span class="comment">// Partially sort the array such that the `amount` elements with the largest + // keys are first using a binary max heap. + </span><span class="kw">let </span><span class="kw-2">mut </span>candidates = BinaryHeap::with_capacity(length.as_usize()); + <span class="kw">let </span><span class="kw-2">mut </span>index = N::zero(); + <span class="kw">while </span>index < length { + <span class="kw">let </span>weight = weight(index.as_usize()).into(); + <span class="kw">if </span>!(weight >= <span class="number">0.</span>) { + <span class="kw">return </span><span class="prelude-val">Err</span>(WeightedError::InvalidWeight); + } + + <span class="kw">let </span>key = rng.gen::<f64>().powf(<span class="number">1.0 </span>/ weight); + candidates.push(Element { index, key }); + + index += N::one(); + } + + <span class="kw">let </span><span class="kw-2">mut </span>result: Vec<N> = Vec::with_capacity(amount.as_usize()); + <span class="kw">while </span>result.len() < amount.as_usize() { + result.push(candidates.pop().unwrap().index); + } + <span class="prelude-val">Ok</span>(IndexVec::from(result)) + } +} + +<span class="doccomment">/// Randomly sample exactly `amount` indices from `0..length`, using Floyd's +/// combination algorithm. +/// +/// The output values are fully shuffled. (Overhead is under 50%.) +/// +/// This implementation uses `O(amount)` memory and `O(amount^2)` time. +</span><span class="kw">fn </span>sample_floyd<R>(rng: <span class="kw-2">&mut </span>R, length: u32, amount: u32) -> IndexVec +<span class="kw">where </span>R: Rng + <span class="question-mark">?</span>Sized { + <span class="comment">// For small amount we use Floyd's fully-shuffled variant. For larger + // amounts this is slow due to Vec::insert performance, so we shuffle + // afterwards. Benchmarks show little overhead from extra logic. + </span><span class="kw">let </span>floyd_shuffle = amount < <span class="number">50</span>; + + <span class="macro">debug_assert!</span>(amount <= length); + <span class="kw">let </span><span class="kw-2">mut </span>indices = Vec::with_capacity(amount <span class="kw">as </span>usize); + <span class="kw">for </span>j <span class="kw">in </span>length - amount..length { + <span class="kw">let </span>t = rng.gen_range(<span class="number">0</span>..=j); + <span class="kw">if </span>floyd_shuffle { + <span class="kw">if let </span><span class="prelude-val">Some</span>(pos) = indices.iter().position(|<span class="kw-2">&</span>x| x == t) { + indices.insert(pos, j); + <span class="kw">continue</span>; + } + } <span class="kw">else if </span>indices.contains(<span class="kw-2">&</span>t) { + indices.push(j); + <span class="kw">continue</span>; + } + indices.push(t); + } + <span class="kw">if </span>!floyd_shuffle { + <span class="comment">// Reimplement SliceRandom::shuffle with smaller indices + </span><span class="kw">for </span>i <span class="kw">in </span>(<span class="number">1</span>..amount).rev() { + <span class="comment">// invariant: elements with index > i have been locked in place. + </span>indices.swap(i <span class="kw">as </span>usize, rng.gen_range(<span class="number">0</span>..=i) <span class="kw">as </span>usize); + } + } + IndexVec::from(indices) +} + +<span class="doccomment">/// Randomly sample exactly `amount` indices from `0..length`, using an inplace +/// partial Fisher-Yates method. +/// Sample an amount of indices using an inplace partial fisher yates method. +/// +/// This allocates the entire `length` of indices and randomizes only the first `amount`. +/// It then truncates to `amount` and returns. +/// +/// This method is not appropriate for large `length` and potentially uses a lot +/// of memory; because of this we only implement for `u32` index (which improves +/// performance in all cases). +/// +/// Set-up is `O(length)` time and memory and shuffling is `O(amount)` time. +</span><span class="kw">fn </span>sample_inplace<R>(rng: <span class="kw-2">&mut </span>R, length: u32, amount: u32) -> IndexVec +<span class="kw">where </span>R: Rng + <span class="question-mark">?</span>Sized { + <span class="macro">debug_assert!</span>(amount <= length); + <span class="kw">let </span><span class="kw-2">mut </span>indices: Vec<u32> = Vec::with_capacity(length <span class="kw">as </span>usize); + indices.extend(<span class="number">0</span>..length); + <span class="kw">for </span>i <span class="kw">in </span><span class="number">0</span>..amount { + <span class="kw">let </span>j: u32 = rng.gen_range(i..length); + indices.swap(i <span class="kw">as </span>usize, j <span class="kw">as </span>usize); + } + indices.truncate(amount <span class="kw">as </span>usize); + <span class="macro">debug_assert_eq!</span>(indices.len(), amount <span class="kw">as </span>usize); + IndexVec::from(indices) +} + +<span class="kw">trait </span>UInt: Copy + PartialOrd + Ord + PartialEq + Eq + SampleUniform + + core::hash::Hash + core::ops::AddAssign { + <span class="kw">fn </span>zero() -> <span class="self">Self</span>; + <span class="kw">fn </span>one() -> <span class="self">Self</span>; + <span class="kw">fn </span>as_usize(<span class="self">self</span>) -> usize; +} +<span class="kw">impl </span>UInt <span class="kw">for </span>u32 { + <span class="attribute">#[inline] + </span><span class="kw">fn </span>zero() -> <span class="self">Self </span>{ + <span class="number">0 + </span>} + + <span class="attribute">#[inline] + </span><span class="kw">fn </span>one() -> <span class="self">Self </span>{ + <span class="number">1 + </span>} + + <span class="attribute">#[inline] + </span><span class="kw">fn </span>as_usize(<span class="self">self</span>) -> usize { + <span class="self">self </span><span class="kw">as </span>usize + } +} +<span class="kw">impl </span>UInt <span class="kw">for </span>usize { + <span class="attribute">#[inline] + </span><span class="kw">fn </span>zero() -> <span class="self">Self </span>{ + <span class="number">0 + </span>} + + <span class="attribute">#[inline] + </span><span class="kw">fn </span>one() -> <span class="self">Self </span>{ + <span class="number">1 + </span>} + + <span class="attribute">#[inline] + </span><span class="kw">fn </span>as_usize(<span class="self">self</span>) -> usize { + <span class="self">self + </span>} +} + +<span class="doccomment">/// Randomly sample exactly `amount` indices from `0..length`, using rejection +/// sampling. +/// +/// Since `amount <<< length` there is a low chance of a random sample in +/// `0..length` being a duplicate. We test for duplicates and resample where +/// necessary. The algorithm is `O(amount)` time and memory. +/// +/// This function is generic over X primarily so that results are value-stable +/// over 32-bit and 64-bit platforms. +</span><span class="kw">fn </span>sample_rejection<X: UInt, R>(rng: <span class="kw-2">&mut </span>R, length: X, amount: X) -> IndexVec +<span class="kw">where + </span>R: Rng + <span class="question-mark">?</span>Sized, + IndexVec: From<Vec<X>>, +{ + <span class="macro">debug_assert!</span>(amount < length); + <span class="attribute">#[cfg(feature = <span class="string">"std"</span>)] + </span><span class="kw">let </span><span class="kw-2">mut </span>cache = HashSet::with_capacity(amount.as_usize()); + <span class="attribute">#[cfg(not(feature = <span class="string">"std"</span>))] + </span><span class="kw">let </span><span class="kw-2">mut </span>cache = BTreeSet::new(); + <span class="kw">let </span>distr = Uniform::new(X::zero(), length); + <span class="kw">let </span><span class="kw-2">mut </span>indices = Vec::with_capacity(amount.as_usize()); + <span class="kw">for _ in </span><span class="number">0</span>..amount.as_usize() { + <span class="kw">let </span><span class="kw-2">mut </span>pos = distr.sample(rng); + <span class="kw">while </span>!cache.insert(pos) { + pos = distr.sample(rng); + } + indices.push(pos); + } + + <span class="macro">debug_assert_eq!</span>(indices.len(), amount.as_usize()); + IndexVec::from(indices) +} + +<span class="attribute">#[cfg(test)] +</span><span class="kw">mod </span>test { + <span class="kw">use super</span>::<span class="kw-2">*</span>; + + <span class="attribute">#[test] + #[cfg(feature = <span class="string">"serde1"</span>)] + </span><span class="kw">fn </span>test_serialization_index_vec() { + <span class="kw">let </span>some_index_vec = IndexVec::from(<span class="macro">vec!</span>[<span class="number">254_usize</span>, <span class="number">234</span>, <span class="number">2</span>, <span class="number">1</span>]); + <span class="kw">let </span>de_some_index_vec: IndexVec = bincode::deserialize(<span class="kw-2">&</span>bincode::serialize(<span class="kw-2">&</span>some_index_vec).unwrap()).unwrap(); + <span class="kw">match </span>(some_index_vec, de_some_index_vec) { + (IndexVec::U32(a), IndexVec::U32(b)) => { + <span class="macro">assert_eq!</span>(a, b); + }, + (IndexVec::USize(a), IndexVec::USize(b)) => { + <span class="macro">assert_eq!</span>(a, b); + }, + <span class="kw">_ </span>=> {<span class="macro">panic!</span>(<span class="string">"failed to seralize/deserialize `IndexVec`"</span>)} + } + } + + <span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] </span><span class="kw">use </span>alloc::vec; + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_sample_boundaries() { + <span class="kw">let </span><span class="kw-2">mut </span>r = <span class="kw">crate</span>::test::rng(<span class="number">404</span>); + + <span class="macro">assert_eq!</span>(sample_inplace(<span class="kw-2">&mut </span>r, <span class="number">0</span>, <span class="number">0</span>).len(), <span class="number">0</span>); + <span class="macro">assert_eq!</span>(sample_inplace(<span class="kw-2">&mut </span>r, <span class="number">1</span>, <span class="number">0</span>).len(), <span class="number">0</span>); + <span class="macro">assert_eq!</span>(sample_inplace(<span class="kw-2">&mut </span>r, <span class="number">1</span>, <span class="number">1</span>).into_vec(), <span class="macro">vec!</span>[<span class="number">0</span>]); + + <span class="macro">assert_eq!</span>(sample_rejection(<span class="kw-2">&mut </span>r, <span class="number">1u32</span>, <span class="number">0</span>).len(), <span class="number">0</span>); + + <span class="macro">assert_eq!</span>(sample_floyd(<span class="kw-2">&mut </span>r, <span class="number">0</span>, <span class="number">0</span>).len(), <span class="number">0</span>); + <span class="macro">assert_eq!</span>(sample_floyd(<span class="kw-2">&mut </span>r, <span class="number">1</span>, <span class="number">0</span>).len(), <span class="number">0</span>); + <span class="macro">assert_eq!</span>(sample_floyd(<span class="kw-2">&mut </span>r, <span class="number">1</span>, <span class="number">1</span>).into_vec(), <span class="macro">vec!</span>[<span class="number">0</span>]); + + <span class="comment">// These algorithms should be fast with big numbers. Test average. + </span><span class="kw">let </span>sum: usize = sample_rejection(<span class="kw-2">&mut </span>r, <span class="number">1 </span><< <span class="number">25</span>, <span class="number">10u32</span>).into_iter().sum(); + <span class="macro">assert!</span>(<span class="number">1 </span><< <span class="number">25 </span>< sum && sum < (<span class="number">1 </span><< <span class="number">25</span>) * <span class="number">25</span>); + + <span class="kw">let </span>sum: usize = sample_floyd(<span class="kw-2">&mut </span>r, <span class="number">1 </span><< <span class="number">25</span>, <span class="number">10</span>).into_iter().sum(); + <span class="macro">assert!</span>(<span class="number">1 </span><< <span class="number">25 </span>< sum && sum < (<span class="number">1 </span><< <span class="number">25</span>) * <span class="number">25</span>); + } + + <span class="attribute">#[test] + #[cfg_attr(miri, ignore)] </span><span class="comment">// Miri is too slow + </span><span class="kw">fn </span>test_sample_alg() { + <span class="kw">let </span>seed_rng = <span class="kw">crate</span>::test::rng; + + <span class="comment">// We can't test which algorithm is used directly, but Floyd's alg + // should produce different results from the others. (Also, `inplace` + // and `cached` currently use different sizes thus produce different results.) + + // A small length and relatively large amount should use inplace + </span><span class="kw">let </span>(length, amount): (usize, usize) = (<span class="number">100</span>, <span class="number">50</span>); + <span class="kw">let </span>v1 = sample(<span class="kw-2">&mut </span>seed_rng(<span class="number">420</span>), length, amount); + <span class="kw">let </span>v2 = sample_inplace(<span class="kw-2">&mut </span>seed_rng(<span class="number">420</span>), length <span class="kw">as </span>u32, amount <span class="kw">as </span>u32); + <span class="macro">assert!</span>(v1.iter().all(|e| e < length)); + <span class="macro">assert_eq!</span>(v1, v2); + + <span class="comment">// Test Floyd's alg does produce different results + </span><span class="kw">let </span>v3 = sample_floyd(<span class="kw-2">&mut </span>seed_rng(<span class="number">420</span>), length <span class="kw">as </span>u32, amount <span class="kw">as </span>u32); + <span class="macro">assert!</span>(v1 != v3); + + <span class="comment">// A large length and small amount should use Floyd + </span><span class="kw">let </span>(length, amount): (usize, usize) = (<span class="number">1 </span><< <span class="number">20</span>, <span class="number">50</span>); + <span class="kw">let </span>v1 = sample(<span class="kw-2">&mut </span>seed_rng(<span class="number">421</span>), length, amount); + <span class="kw">let </span>v2 = sample_floyd(<span class="kw-2">&mut </span>seed_rng(<span class="number">421</span>), length <span class="kw">as </span>u32, amount <span class="kw">as </span>u32); + <span class="macro">assert!</span>(v1.iter().all(|e| e < length)); + <span class="macro">assert_eq!</span>(v1, v2); + + <span class="comment">// A large length and larger amount should use cache + </span><span class="kw">let </span>(length, amount): (usize, usize) = (<span class="number">1 </span><< <span class="number">20</span>, <span class="number">600</span>); + <span class="kw">let </span>v1 = sample(<span class="kw-2">&mut </span>seed_rng(<span class="number">422</span>), length, amount); + <span class="kw">let </span>v2 = sample_rejection(<span class="kw-2">&mut </span>seed_rng(<span class="number">422</span>), length <span class="kw">as </span>u32, amount <span class="kw">as </span>u32); + <span class="macro">assert!</span>(v1.iter().all(|e| e < length)); + <span class="macro">assert_eq!</span>(v1, v2); + } + + <span class="attribute">#[cfg(feature = <span class="string">"std"</span>)] + #[test] + </span><span class="kw">fn </span>test_sample_weighted() { + <span class="kw">let </span>seed_rng = <span class="kw">crate</span>::test::rng; + <span class="kw">for </span><span class="kw-2">&</span>(amount, len) <span class="kw">in </span><span class="kw-2">&</span>[(<span class="number">0</span>, <span class="number">10</span>), (<span class="number">5</span>, <span class="number">10</span>), (<span class="number">10</span>, <span class="number">10</span>)] { + <span class="kw">let </span>v = sample_weighted(<span class="kw-2">&mut </span>seed_rng(<span class="number">423</span>), len, |i| i <span class="kw">as </span>f64, amount).unwrap(); + <span class="kw">match </span>v { + IndexVec::U32(<span class="kw-2">mut </span>indices) => { + <span class="macro">assert_eq!</span>(indices.len(), amount); + indices.sort_unstable(); + indices.dedup(); + <span class="macro">assert_eq!</span>(indices.len(), amount); + <span class="kw">for </span><span class="kw-2">&</span>i <span class="kw">in </span><span class="kw-2">&</span>indices { + <span class="macro">assert!</span>((i <span class="kw">as </span>usize) < len); + } + }, + IndexVec::USize(<span class="kw">_</span>) => <span class="macro">panic!</span>(<span class="string">"expected `IndexVec::U32`"</span>), + } + } + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>value_stability_sample() { + <span class="kw">let </span>do_test = |length, amount, values: <span class="kw-2">&</span>[u32]| { + <span class="kw">let </span><span class="kw-2">mut </span>buf = [<span class="number">0u32</span>; <span class="number">8</span>]; + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">410</span>); + + <span class="kw">let </span>res = sample(<span class="kw-2">&mut </span>rng, length, amount); + <span class="kw">let </span>len = res.len().min(buf.len()); + <span class="kw">for </span>(x, y) <span class="kw">in </span>res.into_iter().zip(buf.iter_mut()) { + <span class="kw-2">*</span>y = x <span class="kw">as </span>u32; + } + <span class="macro">assert_eq!</span>( + <span class="kw-2">&</span>buf[<span class="number">0</span>..len], + values, + <span class="string">"failed sampling {}, {}"</span>, + length, + amount + ); + }; + + do_test(<span class="number">10</span>, <span class="number">6</span>, <span class="kw-2">&</span>[<span class="number">8</span>, <span class="number">0</span>, <span class="number">3</span>, <span class="number">5</span>, <span class="number">9</span>, <span class="number">6</span>]); <span class="comment">// floyd + </span>do_test(<span class="number">25</span>, <span class="number">10</span>, <span class="kw-2">&</span>[<span class="number">18</span>, <span class="number">15</span>, <span class="number">14</span>, <span class="number">9</span>, <span class="number">0</span>, <span class="number">13</span>, <span class="number">5</span>, <span class="number">24</span>]); <span class="comment">// floyd + </span>do_test(<span class="number">300</span>, <span class="number">8</span>, <span class="kw-2">&</span>[<span class="number">30</span>, <span class="number">283</span>, <span class="number">150</span>, <span class="number">1</span>, <span class="number">73</span>, <span class="number">13</span>, <span class="number">285</span>, <span class="number">35</span>]); <span class="comment">// floyd + </span>do_test(<span class="number">300</span>, <span class="number">80</span>, <span class="kw-2">&</span>[<span class="number">31</span>, <span class="number">289</span>, <span class="number">248</span>, <span class="number">154</span>, <span class="number">5</span>, <span class="number">78</span>, <span class="number">19</span>, <span class="number">286</span>]); <span class="comment">// inplace + </span>do_test(<span class="number">300</span>, <span class="number">180</span>, <span class="kw-2">&</span>[<span class="number">31</span>, <span class="number">289</span>, <span class="number">248</span>, <span class="number">154</span>, <span class="number">5</span>, <span class="number">78</span>, <span class="number">19</span>, <span class="number">286</span>]); <span class="comment">// inplace + + </span>do_test(<span class="number">1_000_000</span>, <span class="number">8</span>, <span class="kw-2">&</span>[ + <span class="number">103717</span>, <span class="number">963485</span>, <span class="number">826422</span>, <span class="number">509101</span>, <span class="number">736394</span>, <span class="number">807035</span>, <span class="number">5327</span>, <span class="number">632573</span>, + ]); <span class="comment">// floyd + </span>do_test(<span class="number">1_000_000</span>, <span class="number">180</span>, <span class="kw-2">&</span>[ + <span class="number">103718</span>, <span class="number">963490</span>, <span class="number">826426</span>, <span class="number">509103</span>, <span class="number">736396</span>, <span class="number">807036</span>, <span class="number">5327</span>, <span class="number">632573</span>, + ]); <span class="comment">// rejection + </span>} +} +</code></pre></div> +</section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="rand" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0 (69f9c33d7 2022-12-12) (Arch Linux rust 1:1.66.0-1)" ></div></body></html>
\ No newline at end of file diff --git a/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/seq/mod.rs.html b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/seq/mod.rs.html new file mode 100644 index 0000000..99cd32d --- /dev/null +++ b/rust/theBook/chapter-2-guessing-game/guessing_game/target/doc/src/rand/seq/mod.rs.html @@ -0,0 +1,2715 @@ +<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/home/pico/.local/share/cargo/registry/src/github.com-1ecc6299db9ec823/rand-0.8.5/src/seq/mod.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>mod.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin 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src="../../../wheel.svg"></a></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> +<span id="2">2</span> +<span id="3">3</span> +<span id="4">4</span> +<span id="5">5</span> +<span id="6">6</span> +<span id="7">7</span> +<span id="8">8</span> +<span id="9">9</span> +<span id="10">10</span> +<span id="11">11</span> +<span id="12">12</span> +<span id="13">13</span> +<span id="14">14</span> +<span id="15">15</span> +<span id="16">16</span> +<span id="17">17</span> +<span id="18">18</span> +<span id="19">19</span> +<span id="20">20</span> +<span id="21">21</span> +<span id="22">22</span> +<span id="23">23</span> +<span id="24">24</span> +<span id="25">25</span> +<span id="26">26</span> +<span id="27">27</span> +<span id="28">28</span> +<span id="29">29</span> +<span id="30">30</span> +<span id="31">31</span> +<span id="32">32</span> +<span id="33">33</span> +<span id="34">34</span> +<span id="35">35</span> +<span id="36">36</span> +<span id="37">37</span> +<span id="38">38</span> +<span id="39">39</span> +<span id="40">40</span> +<span id="41">41</span> +<span id="42">42</span> +<span id="43">43</span> +<span id="44">44</span> +<span id="45">45</span> +<span id="46">46</span> +<span id="47">47</span> +<span id="48">48</span> +<span id="49">49</span> +<span id="50">50</span> +<span id="51">51</span> +<span id="52">52</span> +<span id="53">53</span> +<span id="54">54</span> +<span id="55">55</span> +<span id="56">56</span> +<span id="57">57</span> +<span id="58">58</span> +<span id="59">59</span> +<span id="60">60</span> +<span id="61">61</span> +<span id="62">62</span> +<span id="63">63</span> +<span id="64">64</span> +<span id="65">65</span> +<span id="66">66</span> +<span id="67">67</span> +<span id="68">68</span> +<span id="69">69</span> +<span id="70">70</span> +<span id="71">71</span> +<span id="72">72</span> +<span id="73">73</span> +<span id="74">74</span> +<span id="75">75</span> +<span id="76">76</span> +<span id="77">77</span> +<span id="78">78</span> +<span id="79">79</span> +<span id="80">80</span> +<span id="81">81</span> +<span id="82">82</span> +<span id="83">83</span> +<span id="84">84</span> +<span id="85">85</span> +<span id="86">86</span> +<span id="87">87</span> +<span id="88">88</span> +<span id="89">89</span> +<span id="90">90</span> +<span id="91">91</span> +<span id="92">92</span> +<span id="93">93</span> +<span id="94">94</span> +<span id="95">95</span> +<span id="96">96</span> +<span id="97">97</span> +<span id="98">98</span> +<span id="99">99</span> +<span id="100">100</span> +<span id="101">101</span> +<span id="102">102</span> +<span id="103">103</span> +<span id="104">104</span> +<span id="105">105</span> +<span id="106">106</span> +<span id="107">107</span> +<span id="108">108</span> +<span id="109">109</span> +<span id="110">110</span> +<span id="111">111</span> +<span id="112">112</span> +<span id="113">113</span> +<span id="114">114</span> +<span id="115">115</span> +<span id="116">116</span> +<span id="117">117</span> +<span id="118">118</span> +<span id="119">119</span> +<span id="120">120</span> +<span id="121">121</span> +<span id="122">122</span> +<span id="123">123</span> +<span id="124">124</span> +<span id="125">125</span> +<span id="126">126</span> +<span id="127">127</span> +<span id="128">128</span> +<span id="129">129</span> +<span id="130">130</span> +<span id="131">131</span> +<span id="132">132</span> +<span id="133">133</span> +<span id="134">134</span> +<span id="135">135</span> +<span id="136">136</span> +<span id="137">137</span> +<span id="138">138</span> +<span id="139">139</span> +<span id="140">140</span> +<span id="141">141</span> +<span id="142">142</span> +<span id="143">143</span> +<span id="144">144</span> +<span id="145">145</span> +<span id="146">146</span> +<span id="147">147</span> +<span id="148">148</span> +<span id="149">149</span> +<span id="150">150</span> +<span id="151">151</span> +<span id="152">152</span> +<span id="153">153</span> +<span id="154">154</span> +<span id="155">155</span> +<span id="156">156</span> +<span id="157">157</span> +<span id="158">158</span> +<span id="159">159</span> +<span id="160">160</span> +<span id="161">161</span> +<span id="162">162</span> +<span id="163">163</span> +<span id="164">164</span> +<span id="165">165</span> +<span id="166">166</span> +<span id="167">167</span> +<span id="168">168</span> +<span id="169">169</span> +<span id="170">170</span> +<span id="171">171</span> +<span id="172">172</span> +<span id="173">173</span> +<span id="174">174</span> +<span id="175">175</span> +<span id="176">176</span> +<span id="177">177</span> +<span id="178">178</span> +<span id="179">179</span> +<span id="180">180</span> +<span id="181">181</span> +<span id="182">182</span> +<span id="183">183</span> +<span id="184">184</span> +<span id="185">185</span> +<span id="186">186</span> +<span id="187">187</span> +<span id="188">188</span> +<span id="189">189</span> +<span id="190">190</span> +<span id="191">191</span> +<span id="192">192</span> +<span id="193">193</span> +<span id="194">194</span> +<span id="195">195</span> +<span id="196">196</span> +<span id="197">197</span> +<span id="198">198</span> +<span id="199">199</span> +<span id="200">200</span> +<span id="201">201</span> +<span id="202">202</span> +<span id="203">203</span> +<span id="204">204</span> +<span id="205">205</span> +<span id="206">206</span> +<span id="207">207</span> +<span id="208">208</span> +<span id="209">209</span> +<span id="210">210</span> +<span id="211">211</span> +<span id="212">212</span> +<span id="213">213</span> +<span id="214">214</span> +<span id="215">215</span> +<span id="216">216</span> +<span id="217">217</span> +<span id="218">218</span> +<span id="219">219</span> +<span id="220">220</span> +<span id="221">221</span> +<span id="222">222</span> +<span id="223">223</span> +<span id="224">224</span> +<span id="225">225</span> +<span id="226">226</span> +<span id="227">227</span> +<span id="228">228</span> +<span id="229">229</span> +<span id="230">230</span> +<span id="231">231</span> +<span id="232">232</span> +<span id="233">233</span> +<span id="234">234</span> +<span id="235">235</span> +<span id="236">236</span> +<span id="237">237</span> +<span id="238">238</span> +<span id="239">239</span> +<span id="240">240</span> +<span id="241">241</span> +<span id="242">242</span> +<span id="243">243</span> +<span id="244">244</span> +<span id="245">245</span> +<span id="246">246</span> +<span id="247">247</span> +<span id="248">248</span> +<span id="249">249</span> +<span id="250">250</span> +<span id="251">251</span> +<span id="252">252</span> +<span id="253">253</span> +<span id="254">254</span> +<span id="255">255</span> +<span id="256">256</span> +<span id="257">257</span> +<span id="258">258</span> +<span id="259">259</span> +<span id="260">260</span> +<span id="261">261</span> +<span id="262">262</span> +<span id="263">263</span> +<span id="264">264</span> +<span id="265">265</span> +<span id="266">266</span> +<span id="267">267</span> +<span id="268">268</span> +<span id="269">269</span> +<span id="270">270</span> +<span id="271">271</span> +<span id="272">272</span> +<span id="273">273</span> +<span id="274">274</span> +<span id="275">275</span> +<span id="276">276</span> +<span id="277">277</span> +<span id="278">278</span> +<span id="279">279</span> +<span id="280">280</span> +<span id="281">281</span> +<span id="282">282</span> +<span id="283">283</span> +<span id="284">284</span> +<span id="285">285</span> +<span id="286">286</span> +<span id="287">287</span> +<span id="288">288</span> +<span id="289">289</span> +<span id="290">290</span> +<span id="291">291</span> +<span id="292">292</span> +<span id="293">293</span> +<span id="294">294</span> +<span id="295">295</span> +<span id="296">296</span> +<span id="297">297</span> +<span id="298">298</span> +<span id="299">299</span> +<span id="300">300</span> +<span id="301">301</span> +<span id="302">302</span> +<span id="303">303</span> +<span id="304">304</span> +<span id="305">305</span> +<span id="306">306</span> +<span id="307">307</span> +<span id="308">308</span> +<span id="309">309</span> +<span id="310">310</span> +<span id="311">311</span> +<span id="312">312</span> +<span id="313">313</span> +<span id="314">314</span> +<span id="315">315</span> +<span id="316">316</span> +<span id="317">317</span> +<span id="318">318</span> +<span id="319">319</span> +<span id="320">320</span> +<span id="321">321</span> +<span id="322">322</span> +<span id="323">323</span> +<span id="324">324</span> +<span id="325">325</span> +<span id="326">326</span> +<span id="327">327</span> +<span id="328">328</span> +<span id="329">329</span> +<span id="330">330</span> +<span id="331">331</span> +<span id="332">332</span> +<span id="333">333</span> +<span id="334">334</span> +<span id="335">335</span> +<span id="336">336</span> +<span id="337">337</span> +<span id="338">338</span> +<span id="339">339</span> +<span id="340">340</span> +<span id="341">341</span> +<span id="342">342</span> +<span id="343">343</span> +<span id="344">344</span> +<span id="345">345</span> +<span id="346">346</span> +<span id="347">347</span> +<span id="348">348</span> +<span id="349">349</span> +<span id="350">350</span> +<span id="351">351</span> +<span id="352">352</span> +<span id="353">353</span> +<span id="354">354</span> +<span id="355">355</span> +<span id="356">356</span> +<span id="357">357</span> +<span id="358">358</span> +<span id="359">359</span> +<span id="360">360</span> +<span id="361">361</span> +<span id="362">362</span> +<span id="363">363</span> +<span id="364">364</span> +<span id="365">365</span> +<span id="366">366</span> +<span id="367">367</span> +<span id="368">368</span> +<span id="369">369</span> +<span id="370">370</span> +<span id="371">371</span> +<span id="372">372</span> +<span id="373">373</span> +<span id="374">374</span> +<span id="375">375</span> +<span id="376">376</span> +<span id="377">377</span> +<span id="378">378</span> +<span id="379">379</span> +<span id="380">380</span> +<span id="381">381</span> +<span id="382">382</span> +<span id="383">383</span> +<span id="384">384</span> +<span id="385">385</span> +<span id="386">386</span> +<span id="387">387</span> +<span id="388">388</span> +<span id="389">389</span> +<span id="390">390</span> +<span id="391">391</span> +<span id="392">392</span> +<span id="393">393</span> +<span id="394">394</span> +<span id="395">395</span> +<span id="396">396</span> +<span id="397">397</span> +<span id="398">398</span> +<span id="399">399</span> +<span id="400">400</span> +<span id="401">401</span> +<span id="402">402</span> +<span id="403">403</span> +<span id="404">404</span> +<span id="405">405</span> +<span id="406">406</span> +<span id="407">407</span> +<span id="408">408</span> +<span id="409">409</span> 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id="1035">1035</span> +<span id="1036">1036</span> +<span id="1037">1037</span> +<span id="1038">1038</span> +<span id="1039">1039</span> +<span id="1040">1040</span> +<span id="1041">1041</span> +<span id="1042">1042</span> +<span id="1043">1043</span> +<span id="1044">1044</span> +<span id="1045">1045</span> +<span id="1046">1046</span> +<span id="1047">1047</span> +<span id="1048">1048</span> +<span id="1049">1049</span> +<span id="1050">1050</span> +<span id="1051">1051</span> +<span id="1052">1052</span> +<span id="1053">1053</span> +<span id="1054">1054</span> +<span id="1055">1055</span> +<span id="1056">1056</span> +<span id="1057">1057</span> +<span id="1058">1058</span> +<span id="1059">1059</span> +<span id="1060">1060</span> +<span id="1061">1061</span> +<span id="1062">1062</span> +<span id="1063">1063</span> +<span id="1064">1064</span> +<span id="1065">1065</span> +<span id="1066">1066</span> +<span id="1067">1067</span> +<span id="1068">1068</span> +<span 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id="1307">1307</span> +<span id="1308">1308</span> +<span id="1309">1309</span> +<span id="1310">1310</span> +<span id="1311">1311</span> +<span id="1312">1312</span> +<span id="1313">1313</span> +<span id="1314">1314</span> +<span id="1315">1315</span> +<span id="1316">1316</span> +<span id="1317">1317</span> +<span id="1318">1318</span> +<span id="1319">1319</span> +<span id="1320">1320</span> +<span id="1321">1321</span> +<span id="1322">1322</span> +<span id="1323">1323</span> +<span id="1324">1324</span> +<span id="1325">1325</span> +<span id="1326">1326</span> +<span id="1327">1327</span> +<span id="1328">1328</span> +<span id="1329">1329</span> +<span id="1330">1330</span> +<span id="1331">1331</span> +<span id="1332">1332</span> +<span id="1333">1333</span> +<span id="1334">1334</span> +<span id="1335">1335</span> +<span id="1336">1336</span> +<span id="1337">1337</span> +<span id="1338">1338</span> +<span id="1339">1339</span> +<span id="1340">1340</span> +<span id="1341">1341</span> +<span id="1342">1342</span> +<span id="1343">1343</span> +<span id="1344">1344</span> +<span id="1345">1345</span> +<span id="1346">1346</span> +<span id="1347">1347</span> +<span id="1348">1348</span> +<span id="1349">1349</span> +<span id="1350">1350</span> +<span id="1351">1351</span> +<span id="1352">1352</span> +<span id="1353">1353</span> +<span id="1354">1354</span> +<span id="1355">1355</span> +<span id="1356">1356</span> +</pre><pre class="rust"><code><span class="comment">// Copyright 2018 Developers of the Rand project. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +</span><span class="doccomment">//! Sequence-related functionality +//! +//! This module provides: +//! +//! * [`SliceRandom`] slice sampling and mutation +//! * [`IteratorRandom`] iterator sampling +//! * [`index::sample`] low-level API to choose multiple indices from +//! `0..length` +//! +//! Also see: +//! +//! * [`crate::distributions::WeightedIndex`] distribution which provides +//! weighted index sampling. +//! +//! In order to make results reproducible across 32-64 bit architectures, all +//! `usize` indices are sampled as a `u32` where possible (also providing a +//! small performance boost in some cases). + + +</span><span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] +#[cfg_attr(doc_cfg, doc(cfg(feature = <span class="string">"alloc"</span>)))] +</span><span class="kw">pub mod </span>index; + +<span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] </span><span class="kw">use </span>core::ops::Index; + +<span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] </span><span class="kw">use </span>alloc::vec::Vec; + +<span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] +</span><span class="kw">use </span><span class="kw">crate</span>::distributions::uniform::{SampleBorrow, SampleUniform}; +<span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] </span><span class="kw">use </span><span class="kw">crate</span>::distributions::WeightedError; +<span class="kw">use </span><span class="kw">crate</span>::Rng; + +<span class="doccomment">/// Extension trait on slices, providing random mutation and sampling methods. +/// +/// This trait is implemented on all `[T]` slice types, providing several +/// methods for choosing and shuffling elements. You must `use` this trait: +/// +/// ``` +/// use rand::seq::SliceRandom; +/// +/// let mut rng = rand::thread_rng(); +/// let mut bytes = "Hello, random!".to_string().into_bytes(); +/// bytes.shuffle(&mut rng); +/// let str = String::from_utf8(bytes).unwrap(); +/// println!("{}", str); +/// ``` +/// Example output (non-deterministic): +/// ```none +/// l,nmroHado !le +/// ``` +</span><span class="kw">pub trait </span>SliceRandom { + <span class="doccomment">/// The element type. + </span><span class="kw">type </span>Item; + + <span class="doccomment">/// Returns a reference to one random element of the slice, or `None` if the + /// slice is empty. + /// + /// For slices, complexity is `O(1)`. + /// + /// # Example + /// + /// ``` + /// use rand::thread_rng; + /// use rand::seq::SliceRandom; + /// + /// let choices = [1, 2, 4, 8, 16, 32]; + /// let mut rng = thread_rng(); + /// println!("{:?}", choices.choose(&mut rng)); + /// assert_eq!(choices[..0].choose(&mut rng), None); + /// ``` + </span><span class="kw">fn </span>choose<R>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="prelude-ty">Option</span><<span class="kw-2">&</span><span class="self">Self</span>::Item> + <span class="kw">where </span>R: Rng + <span class="question-mark">?</span>Sized; + + <span class="doccomment">/// Returns a mutable reference to one random element of the slice, or + /// `None` if the slice is empty. + /// + /// For slices, complexity is `O(1)`. + </span><span class="kw">fn </span>choose_mut<R>(<span class="kw-2">&mut </span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="prelude-ty">Option</span><<span class="kw-2">&mut </span><span class="self">Self</span>::Item> + <span class="kw">where </span>R: Rng + <span class="question-mark">?</span>Sized; + + <span class="doccomment">/// Chooses `amount` elements from the slice at random, without repetition, + /// and in random order. The returned iterator is appropriate both for + /// collection into a `Vec` and filling an existing buffer (see example). + /// + /// In case this API is not sufficiently flexible, use [`index::sample`]. + /// + /// For slices, complexity is the same as [`index::sample`]. + /// + /// # Example + /// ``` + /// use rand::seq::SliceRandom; + /// + /// let mut rng = &mut rand::thread_rng(); + /// let sample = "Hello, audience!".as_bytes(); + /// + /// // collect the results into a vector: + /// let v: Vec<u8> = sample.choose_multiple(&mut rng, 3).cloned().collect(); + /// + /// // store in a buffer: + /// let mut buf = [0u8; 5]; + /// for (b, slot) in sample.choose_multiple(&mut rng, buf.len()).zip(buf.iter_mut()) { + /// *slot = *b; + /// } + /// ``` + </span><span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] + #[cfg_attr(doc_cfg, doc(cfg(feature = <span class="string">"alloc"</span>)))] + </span><span class="kw">fn </span>choose_multiple<R>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R, amount: usize) -> SliceChooseIter<<span class="self">Self</span>, <span class="self">Self</span>::Item> + <span class="kw">where </span>R: Rng + <span class="question-mark">?</span>Sized; + + <span class="doccomment">/// Similar to [`choose`], but where the likelihood of each outcome may be + /// specified. + /// + /// The specified function `weight` maps each item `x` to a relative + /// likelihood `weight(x)`. The probability of each item being selected is + /// therefore `weight(x) / s`, where `s` is the sum of all `weight(x)`. + /// + /// For slices of length `n`, complexity is `O(n)`. + /// See also [`choose_weighted_mut`], [`distributions::weighted`]. + /// + /// # Example + /// + /// ``` + /// use rand::prelude::*; + /// + /// let choices = [('a', 2), ('b', 1), ('c', 1)]; + /// let mut rng = thread_rng(); + /// // 50% chance to print 'a', 25% chance to print 'b', 25% chance to print 'c' + /// println!("{:?}", choices.choose_weighted(&mut rng, |item| item.1).unwrap().0); + /// ``` + /// [`choose`]: SliceRandom::choose + /// [`choose_weighted_mut`]: SliceRandom::choose_weighted_mut + /// [`distributions::weighted`]: crate::distributions::weighted + </span><span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] + #[cfg_attr(doc_cfg, doc(cfg(feature = <span class="string">"alloc"</span>)))] + </span><span class="kw">fn </span>choose_weighted<R, F, B, X>( + <span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R, weight: F, + ) -> <span class="prelude-ty">Result</span><<span class="kw-2">&</span><span class="self">Self</span>::Item, WeightedError> + <span class="kw">where + </span>R: Rng + <span class="question-mark">?</span>Sized, + F: Fn(<span class="kw-2">&</span><span class="self">Self</span>::Item) -> B, + B: SampleBorrow<X>, + X: SampleUniform + + <span class="kw">for</span><<span class="lifetime">'a</span>> ::core::ops::AddAssign<<span class="kw-2">&</span><span class="lifetime">'a </span>X> + + ::core::cmp::PartialOrd<X> + + Clone + + Default; + + <span class="doccomment">/// Similar to [`choose_mut`], but where the likelihood of each outcome may + /// be specified. + /// + /// The specified function `weight` maps each item `x` to a relative + /// likelihood `weight(x)`. The probability of each item being selected is + /// therefore `weight(x) / s`, where `s` is the sum of all `weight(x)`. + /// + /// For slices of length `n`, complexity is `O(n)`. + /// See also [`choose_weighted`], [`distributions::weighted`]. + /// + /// [`choose_mut`]: SliceRandom::choose_mut + /// [`choose_weighted`]: SliceRandom::choose_weighted + /// [`distributions::weighted`]: crate::distributions::weighted + </span><span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] + #[cfg_attr(doc_cfg, doc(cfg(feature = <span class="string">"alloc"</span>)))] + </span><span class="kw">fn </span>choose_weighted_mut<R, F, B, X>( + <span class="kw-2">&mut </span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R, weight: F, + ) -> <span class="prelude-ty">Result</span><<span class="kw-2">&mut </span><span class="self">Self</span>::Item, WeightedError> + <span class="kw">where + </span>R: Rng + <span class="question-mark">?</span>Sized, + F: Fn(<span class="kw-2">&</span><span class="self">Self</span>::Item) -> B, + B: SampleBorrow<X>, + X: SampleUniform + + <span class="kw">for</span><<span class="lifetime">'a</span>> ::core::ops::AddAssign<<span class="kw-2">&</span><span class="lifetime">'a </span>X> + + ::core::cmp::PartialOrd<X> + + Clone + + Default; + + <span class="doccomment">/// Similar to [`choose_multiple`], but where the likelihood of each element's + /// inclusion in the output may be specified. The elements are returned in an + /// arbitrary, unspecified order. + /// + /// The specified function `weight` maps each item `x` to a relative + /// likelihood `weight(x)`. The probability of each item being selected is + /// therefore `weight(x) / s`, where `s` is the sum of all `weight(x)`. + /// + /// If all of the weights are equal, even if they are all zero, each element has + /// an equal likelihood of being selected. + /// + /// The complexity of this method depends on the feature `partition_at_index`. + /// If the feature is enabled, then for slices of length `n`, the complexity + /// is `O(n)` space and `O(n)` time. Otherwise, the complexity is `O(n)` space and + /// `O(n * log amount)` time. + /// + /// # Example + /// + /// ``` + /// use rand::prelude::*; + /// + /// let choices = [('a', 2), ('b', 1), ('c', 1)]; + /// let mut rng = thread_rng(); + /// // First Draw * Second Draw = total odds + /// // ----------------------- + /// // (50% * 50%) + (25% * 67%) = 41.7% chance that the output is `['a', 'b']` in some order. + /// // (50% * 50%) + (25% * 67%) = 41.7% chance that the output is `['a', 'c']` in some order. + /// // (25% * 33%) + (25% * 33%) = 16.6% chance that the output is `['b', 'c']` in some order. + /// println!("{:?}", choices.choose_multiple_weighted(&mut rng, 2, |item| item.1).unwrap().collect::<Vec<_>>()); + /// ``` + /// [`choose_multiple`]: SliceRandom::choose_multiple + </span><span class="comment">// + // Note: this is feature-gated on std due to usage of f64::powf. + // If necessary, we may use alloc+libm as an alternative (see PR #1089). + </span><span class="attribute">#[cfg(feature = <span class="string">"std"</span>)] + #[cfg_attr(doc_cfg, doc(cfg(feature = <span class="string">"std"</span>)))] + </span><span class="kw">fn </span>choose_multiple_weighted<R, F, X>( + <span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R, amount: usize, weight: F, + ) -> <span class="prelude-ty">Result</span><SliceChooseIter<<span class="self">Self</span>, <span class="self">Self</span>::Item>, WeightedError> + <span class="kw">where + </span>R: Rng + <span class="question-mark">?</span>Sized, + F: Fn(<span class="kw-2">&</span><span class="self">Self</span>::Item) -> X, + X: Into<f64>; + + <span class="doccomment">/// Shuffle a mutable slice in place. + /// + /// For slices of length `n`, complexity is `O(n)`. + /// + /// # Example + /// + /// ``` + /// use rand::seq::SliceRandom; + /// use rand::thread_rng; + /// + /// let mut rng = thread_rng(); + /// let mut y = [1, 2, 3, 4, 5]; + /// println!("Unshuffled: {:?}", y); + /// y.shuffle(&mut rng); + /// println!("Shuffled: {:?}", y); + /// ``` + </span><span class="kw">fn </span>shuffle<R>(<span class="kw-2">&mut </span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) + <span class="kw">where </span>R: Rng + <span class="question-mark">?</span>Sized; + + <span class="doccomment">/// Shuffle a slice in place, but exit early. + /// + /// Returns two mutable slices from the source slice. The first contains + /// `amount` elements randomly permuted. The second has the remaining + /// elements that are not fully shuffled. + /// + /// This is an efficient method to select `amount` elements at random from + /// the slice, provided the slice may be mutated. + /// + /// If you only need to choose elements randomly and `amount > self.len()/2` + /// then you may improve performance by taking + /// `amount = values.len() - amount` and using only the second slice. + /// + /// If `amount` is greater than the number of elements in the slice, this + /// will perform a full shuffle. + /// + /// For slices, complexity is `O(m)` where `m = amount`. + </span><span class="kw">fn </span>partial_shuffle<R>( + <span class="kw-2">&mut </span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R, amount: usize, + ) -> (<span class="kw-2">&mut </span>[<span class="self">Self</span>::Item], <span class="kw-2">&mut </span>[<span class="self">Self</span>::Item]) + <span class="kw">where </span>R: Rng + <span class="question-mark">?</span>Sized; +} + +<span class="doccomment">/// Extension trait on iterators, providing random sampling methods. +/// +/// This trait is implemented on all iterators `I` where `I: Iterator + Sized` +/// and provides methods for +/// choosing one or more elements. You must `use` this trait: +/// +/// ``` +/// use rand::seq::IteratorRandom; +/// +/// let mut rng = rand::thread_rng(); +/// +/// let faces = "😀😎😐😕😠😢"; +/// println!("I am {}!", faces.chars().choose(&mut rng).unwrap()); +/// ``` +/// Example output (non-deterministic): +/// ```none +/// I am 😀! +/// ``` +</span><span class="kw">pub trait </span>IteratorRandom: Iterator + Sized { + <span class="doccomment">/// Choose one element at random from the iterator. + /// + /// Returns `None` if and only if the iterator is empty. + /// + /// This method uses [`Iterator::size_hint`] for optimisation. With an + /// accurate hint and where [`Iterator::nth`] is a constant-time operation + /// this method can offer `O(1)` performance. Where no size hint is + /// available, complexity is `O(n)` where `n` is the iterator length. + /// Partial hints (where `lower > 0`) also improve performance. + /// + /// Note that the output values and the number of RNG samples used + /// depends on size hints. In particular, `Iterator` combinators that don't + /// change the values yielded but change the size hints may result in + /// `choose` returning different elements. If you want consistent results + /// and RNG usage consider using [`IteratorRandom::choose_stable`]. + </span><span class="kw">fn </span>choose<R>(<span class="kw-2">mut </span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>::Item> + <span class="kw">where </span>R: Rng + <span class="question-mark">?</span>Sized { + <span class="kw">let </span>(<span class="kw-2">mut </span>lower, <span class="kw-2">mut </span>upper) = <span class="self">self</span>.size_hint(); + <span class="kw">let </span><span class="kw-2">mut </span>consumed = <span class="number">0</span>; + <span class="kw">let </span><span class="kw-2">mut </span>result = <span class="prelude-val">None</span>; + + <span class="comment">// Handling for this condition outside the loop allows the optimizer to eliminate the loop + // when the Iterator is an ExactSizeIterator. This has a large performance impact on e.g. + // seq_iter_choose_from_1000. + </span><span class="kw">if </span>upper == <span class="prelude-val">Some</span>(lower) { + <span class="kw">return if </span>lower == <span class="number">0 </span>{ + <span class="prelude-val">None + </span>} <span class="kw">else </span>{ + <span class="self">self</span>.nth(gen_index(rng, lower)) + }; + } + + <span class="comment">// Continue until the iterator is exhausted + </span><span class="kw">loop </span>{ + <span class="kw">if </span>lower > <span class="number">1 </span>{ + <span class="kw">let </span>ix = gen_index(rng, lower + consumed); + <span class="kw">let </span>skip = <span class="kw">if </span>ix < lower { + result = <span class="self">self</span>.nth(ix); + lower - (ix + <span class="number">1</span>) + } <span class="kw">else </span>{ + lower + }; + <span class="kw">if </span>upper == <span class="prelude-val">Some</span>(lower) { + <span class="kw">return </span>result; + } + consumed += lower; + <span class="kw">if </span>skip > <span class="number">0 </span>{ + <span class="self">self</span>.nth(skip - <span class="number">1</span>); + } + } <span class="kw">else </span>{ + <span class="kw">let </span>elem = <span class="self">self</span>.next(); + <span class="kw">if </span>elem.is_none() { + <span class="kw">return </span>result; + } + consumed += <span class="number">1</span>; + <span class="kw">if </span>gen_index(rng, consumed) == <span class="number">0 </span>{ + result = elem; + } + } + + <span class="kw">let </span>hint = <span class="self">self</span>.size_hint(); + lower = hint.<span class="number">0</span>; + upper = hint.<span class="number">1</span>; + } + } + + <span class="doccomment">/// Choose one element at random from the iterator. + /// + /// Returns `None` if and only if the iterator is empty. + /// + /// This method is very similar to [`choose`] except that the result + /// only depends on the length of the iterator and the values produced by + /// `rng`. Notably for any iterator of a given length this will make the + /// same requests to `rng` and if the same sequence of values are produced + /// the same index will be selected from `self`. This may be useful if you + /// need consistent results no matter what type of iterator you are working + /// with. If you do not need this stability prefer [`choose`]. + /// + /// Note that this method still uses [`Iterator::size_hint`] to skip + /// constructing elements where possible, however the selection and `rng` + /// calls are the same in the face of this optimization. If you want to + /// force every element to be created regardless call `.inspect(|e| ())`. + /// + /// [`choose`]: IteratorRandom::choose + </span><span class="kw">fn </span>choose_stable<R>(<span class="kw-2">mut </span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>::Item> + <span class="kw">where </span>R: Rng + <span class="question-mark">?</span>Sized { + <span class="kw">let </span><span class="kw-2">mut </span>consumed = <span class="number">0</span>; + <span class="kw">let </span><span class="kw-2">mut </span>result = <span class="prelude-val">None</span>; + + <span class="kw">loop </span>{ + <span class="comment">// Currently the only way to skip elements is `nth()`. So we need to + // store what index to access next here. + // This should be replaced by `advance_by()` once it is stable: + // https://github.com/rust-lang/rust/issues/77404 + </span><span class="kw">let </span><span class="kw-2">mut </span>next = <span class="number">0</span>; + + <span class="kw">let </span>(lower, <span class="kw">_</span>) = <span class="self">self</span>.size_hint(); + <span class="kw">if </span>lower >= <span class="number">2 </span>{ + <span class="kw">let </span>highest_selected = (<span class="number">0</span>..lower) + .filter(|ix| gen_index(rng, consumed+ix+<span class="number">1</span>) == <span class="number">0</span>) + .last(); + + consumed += lower; + next = lower; + + <span class="kw">if let </span><span class="prelude-val">Some</span>(ix) = highest_selected { + result = <span class="self">self</span>.nth(ix); + next -= ix + <span class="number">1</span>; + <span class="macro">debug_assert!</span>(result.is_some(), <span class="string">"iterator shorter than size_hint().0"</span>); + } + } + + <span class="kw">let </span>elem = <span class="self">self</span>.nth(next); + <span class="kw">if </span>elem.is_none() { + <span class="kw">return </span>result + } + + <span class="kw">if </span>gen_index(rng, consumed+<span class="number">1</span>) == <span class="number">0 </span>{ + result = elem; + } + consumed += <span class="number">1</span>; + } + } + + <span class="doccomment">/// Collects values at random from the iterator into a supplied buffer + /// until that buffer is filled. + /// + /// Although the elements are selected randomly, the order of elements in + /// the buffer is neither stable nor fully random. If random ordering is + /// desired, shuffle the result. + /// + /// Returns the number of elements added to the buffer. This equals the length + /// of the buffer unless the iterator contains insufficient elements, in which + /// case this equals the number of elements available. + /// + /// Complexity is `O(n)` where `n` is the length of the iterator. + /// For slices, prefer [`SliceRandom::choose_multiple`]. + </span><span class="kw">fn </span>choose_multiple_fill<R>(<span class="kw-2">mut </span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R, buf: <span class="kw-2">&mut </span>[<span class="self">Self</span>::Item]) -> usize + <span class="kw">where </span>R: Rng + <span class="question-mark">?</span>Sized { + <span class="kw">let </span>amount = buf.len(); + <span class="kw">let </span><span class="kw-2">mut </span>len = <span class="number">0</span>; + <span class="kw">while </span>len < amount { + <span class="kw">if let </span><span class="prelude-val">Some</span>(elem) = <span class="self">self</span>.next() { + buf[len] = elem; + len += <span class="number">1</span>; + } <span class="kw">else </span>{ + <span class="comment">// Iterator exhausted; stop early + </span><span class="kw">return </span>len; + } + } + + <span class="comment">// Continue, since the iterator was not exhausted + </span><span class="kw">for </span>(i, elem) <span class="kw">in </span><span class="self">self</span>.enumerate() { + <span class="kw">let </span>k = gen_index(rng, i + <span class="number">1 </span>+ amount); + <span class="kw">if let </span><span class="prelude-val">Some</span>(slot) = buf.get_mut(k) { + <span class="kw-2">*</span>slot = elem; + } + } + len + } + + <span class="doccomment">/// Collects `amount` values at random from the iterator into a vector. + /// + /// This is equivalent to `choose_multiple_fill` except for the result type. + /// + /// Although the elements are selected randomly, the order of elements in + /// the buffer is neither stable nor fully random. If random ordering is + /// desired, shuffle the result. + /// + /// The length of the returned vector equals `amount` unless the iterator + /// contains insufficient elements, in which case it equals the number of + /// elements available. + /// + /// Complexity is `O(n)` where `n` is the length of the iterator. + /// For slices, prefer [`SliceRandom::choose_multiple`]. + </span><span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] + #[cfg_attr(doc_cfg, doc(cfg(feature = <span class="string">"alloc"</span>)))] + </span><span class="kw">fn </span>choose_multiple<R>(<span class="kw-2">mut </span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R, amount: usize) -> Vec<<span class="self">Self</span>::Item> + <span class="kw">where </span>R: Rng + <span class="question-mark">?</span>Sized { + <span class="kw">let </span><span class="kw-2">mut </span>reservoir = Vec::with_capacity(amount); + reservoir.extend(<span class="self">self</span>.by_ref().take(amount)); + + <span class="comment">// Continue unless the iterator was exhausted + // + // note: this prevents iterators that "restart" from causing problems. + // If the iterator stops once, then so do we. + </span><span class="kw">if </span>reservoir.len() == amount { + <span class="kw">for </span>(i, elem) <span class="kw">in </span><span class="self">self</span>.enumerate() { + <span class="kw">let </span>k = gen_index(rng, i + <span class="number">1 </span>+ amount); + <span class="kw">if let </span><span class="prelude-val">Some</span>(slot) = reservoir.get_mut(k) { + <span class="kw-2">*</span>slot = elem; + } + } + } <span class="kw">else </span>{ + <span class="comment">// Don't hang onto extra memory. There is a corner case where + // `amount` was much less than `self.len()`. + </span>reservoir.shrink_to_fit(); + } + reservoir + } +} + + +<span class="kw">impl</span><T> SliceRandom <span class="kw">for </span>[T] { + <span class="kw">type </span>Item = T; + + <span class="kw">fn </span>choose<R>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="prelude-ty">Option</span><<span class="kw-2">&</span><span class="self">Self</span>::Item> + <span class="kw">where </span>R: Rng + <span class="question-mark">?</span>Sized { + <span class="kw">if </span><span class="self">self</span>.is_empty() { + <span class="prelude-val">None + </span>} <span class="kw">else </span>{ + <span class="prelude-val">Some</span>(<span class="kw-2">&</span><span class="self">self</span>[gen_index(rng, <span class="self">self</span>.len())]) + } + } + + <span class="kw">fn </span>choose_mut<R>(<span class="kw-2">&mut </span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) -> <span class="prelude-ty">Option</span><<span class="kw-2">&mut </span><span class="self">Self</span>::Item> + <span class="kw">where </span>R: Rng + <span class="question-mark">?</span>Sized { + <span class="kw">if </span><span class="self">self</span>.is_empty() { + <span class="prelude-val">None + </span>} <span class="kw">else </span>{ + <span class="kw">let </span>len = <span class="self">self</span>.len(); + <span class="prelude-val">Some</span>(<span class="kw-2">&mut </span><span class="self">self</span>[gen_index(rng, len)]) + } + } + + <span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] + </span><span class="kw">fn </span>choose_multiple<R>(<span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R, amount: usize) -> SliceChooseIter<<span class="self">Self</span>, <span class="self">Self</span>::Item> + <span class="kw">where </span>R: Rng + <span class="question-mark">?</span>Sized { + <span class="kw">let </span>amount = ::core::cmp::min(amount, <span class="self">self</span>.len()); + SliceChooseIter { + slice: <span class="self">self</span>, + _phantom: Default::default(), + indices: index::sample(rng, <span class="self">self</span>.len(), amount).into_iter(), + } + } + + <span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] + </span><span class="kw">fn </span>choose_weighted<R, F, B, X>( + <span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R, weight: F, + ) -> <span class="prelude-ty">Result</span><<span class="kw-2">&</span><span class="self">Self</span>::Item, WeightedError> + <span class="kw">where + </span>R: Rng + <span class="question-mark">?</span>Sized, + F: Fn(<span class="kw-2">&</span><span class="self">Self</span>::Item) -> B, + B: SampleBorrow<X>, + X: SampleUniform + + <span class="kw">for</span><<span class="lifetime">'a</span>> ::core::ops::AddAssign<<span class="kw-2">&</span><span class="lifetime">'a </span>X> + + ::core::cmp::PartialOrd<X> + + Clone + + Default, + { + <span class="kw">use </span><span class="kw">crate</span>::distributions::{Distribution, WeightedIndex}; + <span class="kw">let </span>distr = WeightedIndex::new(<span class="self">self</span>.iter().map(weight))<span class="question-mark">?</span>; + <span class="prelude-val">Ok</span>(<span class="kw-2">&</span><span class="self">self</span>[distr.sample(rng)]) + } + + <span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] + </span><span class="kw">fn </span>choose_weighted_mut<R, F, B, X>( + <span class="kw-2">&mut </span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R, weight: F, + ) -> <span class="prelude-ty">Result</span><<span class="kw-2">&mut </span><span class="self">Self</span>::Item, WeightedError> + <span class="kw">where + </span>R: Rng + <span class="question-mark">?</span>Sized, + F: Fn(<span class="kw-2">&</span><span class="self">Self</span>::Item) -> B, + B: SampleBorrow<X>, + X: SampleUniform + + <span class="kw">for</span><<span class="lifetime">'a</span>> ::core::ops::AddAssign<<span class="kw-2">&</span><span class="lifetime">'a </span>X> + + ::core::cmp::PartialOrd<X> + + Clone + + Default, + { + <span class="kw">use </span><span class="kw">crate</span>::distributions::{Distribution, WeightedIndex}; + <span class="kw">let </span>distr = WeightedIndex::new(<span class="self">self</span>.iter().map(weight))<span class="question-mark">?</span>; + <span class="prelude-val">Ok</span>(<span class="kw-2">&mut </span><span class="self">self</span>[distr.sample(rng)]) + } + + <span class="attribute">#[cfg(feature = <span class="string">"std"</span>)] + </span><span class="kw">fn </span>choose_multiple_weighted<R, F, X>( + <span class="kw-2">&</span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R, amount: usize, weight: F, + ) -> <span class="prelude-ty">Result</span><SliceChooseIter<<span class="self">Self</span>, <span class="self">Self</span>::Item>, WeightedError> + <span class="kw">where + </span>R: Rng + <span class="question-mark">?</span>Sized, + F: Fn(<span class="kw-2">&</span><span class="self">Self</span>::Item) -> X, + X: Into<f64>, + { + <span class="kw">let </span>amount = ::core::cmp::min(amount, <span class="self">self</span>.len()); + <span class="prelude-val">Ok</span>(SliceChooseIter { + slice: <span class="self">self</span>, + _phantom: Default::default(), + indices: index::sample_weighted( + rng, + <span class="self">self</span>.len(), + |idx| weight(<span class="kw-2">&</span><span class="self">self</span>[idx]).into(), + amount, + )<span class="question-mark">? + </span>.into_iter(), + }) + } + + <span class="kw">fn </span>shuffle<R>(<span class="kw-2">&mut </span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R) + <span class="kw">where </span>R: Rng + <span class="question-mark">?</span>Sized { + <span class="kw">for </span>i <span class="kw">in </span>(<span class="number">1</span>..<span class="self">self</span>.len()).rev() { + <span class="comment">// invariant: elements with index > i have been locked in place. + </span><span class="self">self</span>.swap(i, gen_index(rng, i + <span class="number">1</span>)); + } + } + + <span class="kw">fn </span>partial_shuffle<R>( + <span class="kw-2">&mut </span><span class="self">self</span>, rng: <span class="kw-2">&mut </span>R, amount: usize, + ) -> (<span class="kw-2">&mut </span>[<span class="self">Self</span>::Item], <span class="kw-2">&mut </span>[<span class="self">Self</span>::Item]) + <span class="kw">where </span>R: Rng + <span class="question-mark">?</span>Sized { + <span class="comment">// This applies Durstenfeld's algorithm for the + // [Fisher–Yates shuffle](https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle#The_modern_algorithm) + // for an unbiased permutation, but exits early after choosing `amount` + // elements. + + </span><span class="kw">let </span>len = <span class="self">self</span>.len(); + <span class="kw">let </span>end = <span class="kw">if </span>amount >= len { <span class="number">0 </span>} <span class="kw">else </span>{ len - amount }; + + <span class="kw">for </span>i <span class="kw">in </span>(end..len).rev() { + <span class="comment">// invariant: elements with index > i have been locked in place. + </span><span class="self">self</span>.swap(i, gen_index(rng, i + <span class="number">1</span>)); + } + <span class="kw">let </span>r = <span class="self">self</span>.split_at_mut(end); + (r.<span class="number">1</span>, r.<span class="number">0</span>) + } +} + +<span class="kw">impl</span><I> IteratorRandom <span class="kw">for </span>I <span class="kw">where </span>I: Iterator + Sized {} + + +<span class="doccomment">/// An iterator over multiple slice elements. +/// +/// This struct is created by +/// [`SliceRandom::choose_multiple`](trait.SliceRandom.html#tymethod.choose_multiple). +</span><span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] +#[cfg_attr(doc_cfg, doc(cfg(feature = <span class="string">"alloc"</span>)))] +#[derive(Debug)] +</span><span class="kw">pub struct </span>SliceChooseIter<<span class="lifetime">'a</span>, S: <span class="question-mark">?</span>Sized + <span class="lifetime">'a</span>, T: <span class="lifetime">'a</span>> { + slice: <span class="kw-2">&</span><span class="lifetime">'a </span>S, + _phantom: ::core::marker::PhantomData<T>, + indices: index::IndexVecIntoIter, +} + +<span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] +</span><span class="kw">impl</span><<span class="lifetime">'a</span>, S: Index<usize, Output = T> + <span class="question-mark">?</span>Sized + <span class="lifetime">'a</span>, T: <span class="lifetime">'a</span>> Iterator <span class="kw">for </span>SliceChooseIter<<span class="lifetime">'a</span>, S, T> { + <span class="kw">type </span>Item = <span class="kw-2">&</span><span class="lifetime">'a </span>T; + + <span class="kw">fn </span>next(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>::Item> { + <span class="comment">// TODO: investigate using SliceIndex::get_unchecked when stable + </span><span class="self">self</span>.indices.next().map(|i| <span class="kw-2">&</span><span class="self">self</span>.slice[i <span class="kw">as </span>usize]) + } + + <span class="kw">fn </span>size_hint(<span class="kw-2">&</span><span class="self">self</span>) -> (usize, <span class="prelude-ty">Option</span><usize>) { + (<span class="self">self</span>.indices.len(), <span class="prelude-val">Some</span>(<span class="self">self</span>.indices.len())) + } +} + +<span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] +</span><span class="kw">impl</span><<span class="lifetime">'a</span>, S: Index<usize, Output = T> + <span class="question-mark">?</span>Sized + <span class="lifetime">'a</span>, T: <span class="lifetime">'a</span>> ExactSizeIterator + <span class="kw">for </span>SliceChooseIter<<span class="lifetime">'a</span>, S, T> +{ + <span class="kw">fn </span>len(<span class="kw-2">&</span><span class="self">self</span>) -> usize { + <span class="self">self</span>.indices.len() + } +} + + +<span class="comment">// Sample a number uniformly between 0 and `ubound`. Uses 32-bit sampling where +// possible, primarily in order to produce the same output on 32-bit and 64-bit +// platforms. +</span><span class="attribute">#[inline] +</span><span class="kw">fn </span>gen_index<R: Rng + <span class="question-mark">?</span>Sized>(rng: <span class="kw-2">&mut </span>R, ubound: usize) -> usize { + <span class="kw">if </span>ubound <= (core::u32::MAX <span class="kw">as </span>usize) { + rng.gen_range(<span class="number">0</span>..ubound <span class="kw">as </span>u32) <span class="kw">as </span>usize + } <span class="kw">else </span>{ + rng.gen_range(<span class="number">0</span>..ubound) + } +} + + +<span class="attribute">#[cfg(test)] +</span><span class="kw">mod </span>test { + <span class="kw">use super</span>::<span class="kw-2">*</span>; + <span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] </span><span class="kw">use </span><span class="kw">crate</span>::Rng; + <span class="attribute">#[cfg(all(feature = <span class="string">"alloc"</span>, not(feature = <span class="string">"std"</span>)))] </span><span class="kw">use </span>alloc::vec::Vec; + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_slice_choose() { + <span class="kw">let </span><span class="kw-2">mut </span>r = <span class="kw">crate</span>::test::rng(<span class="number">107</span>); + <span class="kw">let </span>chars = [ + <span class="string">'a'</span>, <span class="string">'b'</span>, <span class="string">'c'</span>, <span class="string">'d'</span>, <span class="string">'e'</span>, <span class="string">'f'</span>, <span class="string">'g'</span>, <span class="string">'h'</span>, <span class="string">'i'</span>, <span class="string">'j'</span>, <span class="string">'k'</span>, <span class="string">'l'</span>, <span class="string">'m'</span>, <span class="string">'n'</span>, + ]; + <span class="kw">let </span><span class="kw-2">mut </span>chosen = [<span class="number">0i32</span>; <span class="number">14</span>]; + <span class="comment">// The below all use a binomial distribution with n=1000, p=1/14. + // binocdf(40, 1000, 1/14) ~= 2e-5; 1-binocdf(106, ..) ~= 2e-5 + </span><span class="kw">for _ in </span><span class="number">0</span>..<span class="number">1000 </span>{ + <span class="kw">let </span>picked = <span class="kw-2">*</span>chars.choose(<span class="kw-2">&mut </span>r).unwrap(); + chosen[(picked <span class="kw">as </span>usize) - (<span class="string">'a' </span><span class="kw">as </span>usize)] += <span class="number">1</span>; + } + <span class="kw">for </span>count <span class="kw">in </span>chosen.iter() { + <span class="macro">assert!</span>(<span class="number">40 </span>< <span class="kw-2">*</span>count && <span class="kw-2">*</span>count < <span class="number">106</span>); + } + + chosen.iter_mut().for_each(|x| <span class="kw-2">*</span>x = <span class="number">0</span>); + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">1000 </span>{ + <span class="kw-2">*</span>chosen.choose_mut(<span class="kw-2">&mut </span>r).unwrap() += <span class="number">1</span>; + } + <span class="kw">for </span>count <span class="kw">in </span>chosen.iter() { + <span class="macro">assert!</span>(<span class="number">40 </span>< <span class="kw-2">*</span>count && <span class="kw-2">*</span>count < <span class="number">106</span>); + } + + <span class="kw">let </span><span class="kw-2">mut </span>v: [isize; <span class="number">0</span>] = []; + <span class="macro">assert_eq!</span>(v.choose(<span class="kw-2">&mut </span>r), <span class="prelude-val">None</span>); + <span class="macro">assert_eq!</span>(v.choose_mut(<span class="kw-2">&mut </span>r), <span class="prelude-val">None</span>); + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>value_stability_slice() { + <span class="kw">let </span><span class="kw-2">mut </span>r = <span class="kw">crate</span>::test::rng(<span class="number">413</span>); + <span class="kw">let </span>chars = [ + <span class="string">'a'</span>, <span class="string">'b'</span>, <span class="string">'c'</span>, <span class="string">'d'</span>, <span class="string">'e'</span>, <span class="string">'f'</span>, <span class="string">'g'</span>, <span class="string">'h'</span>, <span class="string">'i'</span>, <span class="string">'j'</span>, <span class="string">'k'</span>, <span class="string">'l'</span>, <span class="string">'m'</span>, <span class="string">'n'</span>, + ]; + <span class="kw">let </span><span class="kw-2">mut </span>nums = [<span class="number">0</span>, <span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>, <span class="number">6</span>, <span class="number">7</span>, <span class="number">8</span>, <span class="number">9</span>, <span class="number">10</span>, <span class="number">11</span>, <span class="number">12</span>]; + + <span class="macro">assert_eq!</span>(chars.choose(<span class="kw-2">&mut </span>r), <span class="prelude-val">Some</span>(<span class="kw-2">&</span><span class="string">'l'</span>)); + <span class="macro">assert_eq!</span>(nums.choose_mut(<span class="kw-2">&mut </span>r), <span class="prelude-val">Some</span>(<span class="kw-2">&mut </span><span class="number">10</span>)); + + <span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] + </span><span class="macro">assert_eq!</span>( + <span class="kw-2">&</span>chars + .choose_multiple(<span class="kw-2">&mut </span>r, <span class="number">8</span>) + .cloned() + .collect::<Vec<char>>(), + <span class="kw-2">&</span>[<span class="string">'d'</span>, <span class="string">'m'</span>, <span class="string">'b'</span>, <span class="string">'n'</span>, <span class="string">'c'</span>, <span class="string">'k'</span>, <span class="string">'h'</span>, <span class="string">'e'</span>] + ); + + <span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] + </span><span class="macro">assert_eq!</span>(chars.choose_weighted(<span class="kw-2">&mut </span>r, |<span class="kw">_</span>| <span class="number">1</span>), <span class="prelude-val">Ok</span>(<span class="kw-2">&</span><span class="string">'f'</span>)); + <span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] + </span><span class="macro">assert_eq!</span>(nums.choose_weighted_mut(<span class="kw-2">&mut </span>r, |<span class="kw">_</span>| <span class="number">1</span>), <span class="prelude-val">Ok</span>(<span class="kw-2">&mut </span><span class="number">5</span>)); + + <span class="kw">let </span><span class="kw-2">mut </span>r = <span class="kw">crate</span>::test::rng(<span class="number">414</span>); + nums.shuffle(<span class="kw-2">&mut </span>r); + <span class="macro">assert_eq!</span>(nums, [<span class="number">9</span>, <span class="number">5</span>, <span class="number">3</span>, <span class="number">10</span>, <span class="number">7</span>, <span class="number">12</span>, <span class="number">8</span>, <span class="number">11</span>, <span class="number">6</span>, <span class="number">4</span>, <span class="number">0</span>, <span class="number">2</span>, <span class="number">1</span>]); + nums = [<span class="number">0</span>, <span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>, <span class="number">6</span>, <span class="number">7</span>, <span class="number">8</span>, <span class="number">9</span>, <span class="number">10</span>, <span class="number">11</span>, <span class="number">12</span>]; + <span class="kw">let </span>res = nums.partial_shuffle(<span class="kw-2">&mut </span>r, <span class="number">6</span>); + <span class="macro">assert_eq!</span>(res.<span class="number">0</span>, <span class="kw-2">&mut </span>[<span class="number">7</span>, <span class="number">4</span>, <span class="number">8</span>, <span class="number">6</span>, <span class="number">9</span>, <span class="number">3</span>]); + <span class="macro">assert_eq!</span>(res.<span class="number">1</span>, <span class="kw-2">&mut </span>[<span class="number">0</span>, <span class="number">1</span>, <span class="number">2</span>, <span class="number">12</span>, <span class="number">11</span>, <span class="number">5</span>, <span class="number">10</span>]); + } + + <span class="attribute">#[derive(Clone)] + </span><span class="kw">struct </span>UnhintedIterator<I: Iterator + Clone> { + iter: I, + } + <span class="kw">impl</span><I: Iterator + Clone> Iterator <span class="kw">for </span>UnhintedIterator<I> { + <span class="kw">type </span>Item = I::Item; + + <span class="kw">fn </span>next(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>::Item> { + <span class="self">self</span>.iter.next() + } + } + + <span class="attribute">#[derive(Clone)] + </span><span class="kw">struct </span>ChunkHintedIterator<I: ExactSizeIterator + Iterator + Clone> { + iter: I, + chunk_remaining: usize, + chunk_size: usize, + hint_total_size: bool, + } + <span class="kw">impl</span><I: ExactSizeIterator + Iterator + Clone> Iterator <span class="kw">for </span>ChunkHintedIterator<I> { + <span class="kw">type </span>Item = I::Item; + + <span class="kw">fn </span>next(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>::Item> { + <span class="kw">if </span><span class="self">self</span>.chunk_remaining == <span class="number">0 </span>{ + <span class="self">self</span>.chunk_remaining = ::core::cmp::min(<span class="self">self</span>.chunk_size, <span class="self">self</span>.iter.len()); + } + <span class="self">self</span>.chunk_remaining = <span class="self">self</span>.chunk_remaining.saturating_sub(<span class="number">1</span>); + + <span class="self">self</span>.iter.next() + } + + <span class="kw">fn </span>size_hint(<span class="kw-2">&</span><span class="self">self</span>) -> (usize, <span class="prelude-ty">Option</span><usize>) { + ( + <span class="self">self</span>.chunk_remaining, + <span class="kw">if </span><span class="self">self</span>.hint_total_size { + <span class="prelude-val">Some</span>(<span class="self">self</span>.iter.len()) + } <span class="kw">else </span>{ + <span class="prelude-val">None + </span>}, + ) + } + } + + <span class="attribute">#[derive(Clone)] + </span><span class="kw">struct </span>WindowHintedIterator<I: ExactSizeIterator + Iterator + Clone> { + iter: I, + window_size: usize, + hint_total_size: bool, + } + <span class="kw">impl</span><I: ExactSizeIterator + Iterator + Clone> Iterator <span class="kw">for </span>WindowHintedIterator<I> { + <span class="kw">type </span>Item = I::Item; + + <span class="kw">fn </span>next(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>::Item> { + <span class="self">self</span>.iter.next() + } + + <span class="kw">fn </span>size_hint(<span class="kw-2">&</span><span class="self">self</span>) -> (usize, <span class="prelude-ty">Option</span><usize>) { + ( + ::core::cmp::min(<span class="self">self</span>.iter.len(), <span class="self">self</span>.window_size), + <span class="kw">if </span><span class="self">self</span>.hint_total_size { + <span class="prelude-val">Some</span>(<span class="self">self</span>.iter.len()) + } <span class="kw">else </span>{ + <span class="prelude-val">None + </span>}, + ) + } + } + + <span class="attribute">#[test] + #[cfg_attr(miri, ignore)] </span><span class="comment">// Miri is too slow + </span><span class="kw">fn </span>test_iterator_choose() { + <span class="kw">let </span>r = <span class="kw-2">&mut </span><span class="kw">crate</span>::test::rng(<span class="number">109</span>); + <span class="kw">fn </span>test_iter<R: Rng + <span class="question-mark">?</span>Sized, Iter: Iterator<Item = usize> + Clone>(r: <span class="kw-2">&mut </span>R, iter: Iter) { + <span class="kw">let </span><span class="kw-2">mut </span>chosen = [<span class="number">0i32</span>; <span class="number">9</span>]; + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">1000 </span>{ + <span class="kw">let </span>picked = iter.clone().choose(r).unwrap(); + chosen[picked] += <span class="number">1</span>; + } + <span class="kw">for </span>count <span class="kw">in </span>chosen.iter() { + <span class="comment">// Samples should follow Binomial(1000, 1/9) + // Octave: binopdf(x, 1000, 1/9) gives the prob of *count == x + // Note: have seen 153, which is unlikely but not impossible. + </span><span class="macro">assert!</span>( + <span class="number">72 </span>< <span class="kw-2">*</span>count && <span class="kw-2">*</span>count < <span class="number">154</span>, + <span class="string">"count not close to 1000/9: {}"</span>, + count + ); + } + } + + test_iter(r, <span class="number">0</span>..<span class="number">9</span>); + test_iter(r, [<span class="number">0</span>, <span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>, <span class="number">6</span>, <span class="number">7</span>, <span class="number">8</span>].iter().cloned()); + <span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] + </span>test_iter(r, (<span class="number">0</span>..<span class="number">9</span>).collect::<Vec<<span class="kw">_</span>>>().into_iter()); + test_iter(r, UnhintedIterator { iter: <span class="number">0</span>..<span class="number">9 </span>}); + test_iter(r, ChunkHintedIterator { + iter: <span class="number">0</span>..<span class="number">9</span>, + chunk_size: <span class="number">4</span>, + chunk_remaining: <span class="number">4</span>, + hint_total_size: <span class="bool-val">false</span>, + }); + test_iter(r, ChunkHintedIterator { + iter: <span class="number">0</span>..<span class="number">9</span>, + chunk_size: <span class="number">4</span>, + chunk_remaining: <span class="number">4</span>, + hint_total_size: <span class="bool-val">true</span>, + }); + test_iter(r, WindowHintedIterator { + iter: <span class="number">0</span>..<span class="number">9</span>, + window_size: <span class="number">2</span>, + hint_total_size: <span class="bool-val">false</span>, + }); + test_iter(r, WindowHintedIterator { + iter: <span class="number">0</span>..<span class="number">9</span>, + window_size: <span class="number">2</span>, + hint_total_size: <span class="bool-val">true</span>, + }); + + <span class="macro">assert_eq!</span>((<span class="number">0</span>..<span class="number">0</span>).choose(r), <span class="prelude-val">None</span>); + <span class="macro">assert_eq!</span>(UnhintedIterator { iter: <span class="number">0</span>..<span class="number">0 </span>}.choose(r), <span class="prelude-val">None</span>); + } + + <span class="attribute">#[test] + #[cfg_attr(miri, ignore)] </span><span class="comment">// Miri is too slow + </span><span class="kw">fn </span>test_iterator_choose_stable() { + <span class="kw">let </span>r = <span class="kw-2">&mut </span><span class="kw">crate</span>::test::rng(<span class="number">109</span>); + <span class="kw">fn </span>test_iter<R: Rng + <span class="question-mark">?</span>Sized, Iter: Iterator<Item = usize> + Clone>(r: <span class="kw-2">&mut </span>R, iter: Iter) { + <span class="kw">let </span><span class="kw-2">mut </span>chosen = [<span class="number">0i32</span>; <span class="number">9</span>]; + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">1000 </span>{ + <span class="kw">let </span>picked = iter.clone().choose_stable(r).unwrap(); + chosen[picked] += <span class="number">1</span>; + } + <span class="kw">for </span>count <span class="kw">in </span>chosen.iter() { + <span class="comment">// Samples should follow Binomial(1000, 1/9) + // Octave: binopdf(x, 1000, 1/9) gives the prob of *count == x + // Note: have seen 153, which is unlikely but not impossible. + </span><span class="macro">assert!</span>( + <span class="number">72 </span>< <span class="kw-2">*</span>count && <span class="kw-2">*</span>count < <span class="number">154</span>, + <span class="string">"count not close to 1000/9: {}"</span>, + count + ); + } + } + + test_iter(r, <span class="number">0</span>..<span class="number">9</span>); + test_iter(r, [<span class="number">0</span>, <span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>, <span class="number">6</span>, <span class="number">7</span>, <span class="number">8</span>].iter().cloned()); + <span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] + </span>test_iter(r, (<span class="number">0</span>..<span class="number">9</span>).collect::<Vec<<span class="kw">_</span>>>().into_iter()); + test_iter(r, UnhintedIterator { iter: <span class="number">0</span>..<span class="number">9 </span>}); + test_iter(r, ChunkHintedIterator { + iter: <span class="number">0</span>..<span class="number">9</span>, + chunk_size: <span class="number">4</span>, + chunk_remaining: <span class="number">4</span>, + hint_total_size: <span class="bool-val">false</span>, + }); + test_iter(r, ChunkHintedIterator { + iter: <span class="number">0</span>..<span class="number">9</span>, + chunk_size: <span class="number">4</span>, + chunk_remaining: <span class="number">4</span>, + hint_total_size: <span class="bool-val">true</span>, + }); + test_iter(r, WindowHintedIterator { + iter: <span class="number">0</span>..<span class="number">9</span>, + window_size: <span class="number">2</span>, + hint_total_size: <span class="bool-val">false</span>, + }); + test_iter(r, WindowHintedIterator { + iter: <span class="number">0</span>..<span class="number">9</span>, + window_size: <span class="number">2</span>, + hint_total_size: <span class="bool-val">true</span>, + }); + + <span class="macro">assert_eq!</span>((<span class="number">0</span>..<span class="number">0</span>).choose(r), <span class="prelude-val">None</span>); + <span class="macro">assert_eq!</span>(UnhintedIterator { iter: <span class="number">0</span>..<span class="number">0 </span>}.choose(r), <span class="prelude-val">None</span>); + } + + <span class="attribute">#[test] + #[cfg_attr(miri, ignore)] </span><span class="comment">// Miri is too slow + </span><span class="kw">fn </span>test_iterator_choose_stable_stability() { + <span class="kw">fn </span>test_iter(iter: <span class="kw">impl </span>Iterator<Item = usize> + Clone) -> [i32; <span class="number">9</span>] { + <span class="kw">let </span>r = <span class="kw-2">&mut </span><span class="kw">crate</span>::test::rng(<span class="number">109</span>); + <span class="kw">let </span><span class="kw-2">mut </span>chosen = [<span class="number">0i32</span>; <span class="number">9</span>]; + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">1000 </span>{ + <span class="kw">let </span>picked = iter.clone().choose_stable(r).unwrap(); + chosen[picked] += <span class="number">1</span>; + } + chosen + } + + <span class="kw">let </span>reference = test_iter(<span class="number">0</span>..<span class="number">9</span>); + <span class="macro">assert_eq!</span>(test_iter([<span class="number">0</span>, <span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>, <span class="number">6</span>, <span class="number">7</span>, <span class="number">8</span>].iter().cloned()), reference); + + <span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] + </span><span class="macro">assert_eq!</span>(test_iter((<span class="number">0</span>..<span class="number">9</span>).collect::<Vec<<span class="kw">_</span>>>().into_iter()), reference); + <span class="macro">assert_eq!</span>(test_iter(UnhintedIterator { iter: <span class="number">0</span>..<span class="number">9 </span>}), reference); + <span class="macro">assert_eq!</span>(test_iter(ChunkHintedIterator { + iter: <span class="number">0</span>..<span class="number">9</span>, + chunk_size: <span class="number">4</span>, + chunk_remaining: <span class="number">4</span>, + hint_total_size: <span class="bool-val">false</span>, + }), reference); + <span class="macro">assert_eq!</span>(test_iter(ChunkHintedIterator { + iter: <span class="number">0</span>..<span class="number">9</span>, + chunk_size: <span class="number">4</span>, + chunk_remaining: <span class="number">4</span>, + hint_total_size: <span class="bool-val">true</span>, + }), reference); + <span class="macro">assert_eq!</span>(test_iter(WindowHintedIterator { + iter: <span class="number">0</span>..<span class="number">9</span>, + window_size: <span class="number">2</span>, + hint_total_size: <span class="bool-val">false</span>, + }), reference); + <span class="macro">assert_eq!</span>(test_iter(WindowHintedIterator { + iter: <span class="number">0</span>..<span class="number">9</span>, + window_size: <span class="number">2</span>, + hint_total_size: <span class="bool-val">true</span>, + }), reference); + } + + <span class="attribute">#[test] + #[cfg_attr(miri, ignore)] </span><span class="comment">// Miri is too slow + </span><span class="kw">fn </span>test_shuffle() { + <span class="kw">let </span><span class="kw-2">mut </span>r = <span class="kw">crate</span>::test::rng(<span class="number">108</span>); + <span class="kw">let </span>empty: <span class="kw-2">&mut </span>[isize] = <span class="kw-2">&mut </span>[]; + empty.shuffle(<span class="kw-2">&mut </span>r); + <span class="kw">let </span><span class="kw-2">mut </span>one = [<span class="number">1</span>]; + one.shuffle(<span class="kw-2">&mut </span>r); + <span class="kw">let </span>b: <span class="kw-2">&</span>[<span class="kw">_</span>] = <span class="kw-2">&</span>[<span class="number">1</span>]; + <span class="macro">assert_eq!</span>(one, b); + + <span class="kw">let </span><span class="kw-2">mut </span>two = [<span class="number">1</span>, <span class="number">2</span>]; + two.shuffle(<span class="kw-2">&mut </span>r); + <span class="macro">assert!</span>(two == [<span class="number">1</span>, <span class="number">2</span>] || two == [<span class="number">2</span>, <span class="number">1</span>]); + + <span class="kw">fn </span>move_last(slice: <span class="kw-2">&mut </span>[usize], pos: usize) { + <span class="comment">// use slice[pos..].rotate_left(1); once we can use that + </span><span class="kw">let </span>last_val = slice[pos]; + <span class="kw">for </span>i <span class="kw">in </span>pos..slice.len() - <span class="number">1 </span>{ + slice[i] = slice[i + <span class="number">1</span>]; + } + <span class="kw-2">*</span>slice.last_mut().unwrap() = last_val; + } + <span class="kw">let </span><span class="kw-2">mut </span>counts = [<span class="number">0i32</span>; <span class="number">24</span>]; + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">10000 </span>{ + <span class="kw">let </span><span class="kw-2">mut </span>arr: [usize; <span class="number">4</span>] = [<span class="number">0</span>, <span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>]; + arr.shuffle(<span class="kw-2">&mut </span>r); + <span class="kw">let </span><span class="kw-2">mut </span>permutation = <span class="number">0usize</span>; + <span class="kw">let </span><span class="kw-2">mut </span>pos_value = counts.len(); + <span class="kw">for </span>i <span class="kw">in </span><span class="number">0</span>..<span class="number">4 </span>{ + pos_value /= <span class="number">4 </span>- i; + <span class="kw">let </span>pos = arr.iter().position(|<span class="kw-2">&</span>x| x == i).unwrap(); + <span class="macro">assert!</span>(pos < (<span class="number">4 </span>- i)); + permutation += pos * pos_value; + move_last(<span class="kw-2">&mut </span>arr, pos); + <span class="macro">assert_eq!</span>(arr[<span class="number">3</span>], i); + } + <span class="kw">for </span>(i, <span class="kw-2">&</span>a) <span class="kw">in </span>arr.iter().enumerate() { + <span class="macro">assert_eq!</span>(a, i); + } + counts[permutation] += <span class="number">1</span>; + } + <span class="kw">for </span>count <span class="kw">in </span>counts.iter() { + <span class="comment">// Binomial(10000, 1/24) with average 416.667 + // Octave: binocdf(n, 10000, 1/24) + // 99.9% chance samples lie within this range: + </span><span class="macro">assert!</span>(<span class="number">352 </span><= <span class="kw-2">*</span>count && <span class="kw-2">*</span>count <= <span class="number">483</span>, <span class="string">"count: {}"</span>, count); + } + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>test_partial_shuffle() { + <span class="kw">let </span><span class="kw-2">mut </span>r = <span class="kw">crate</span>::test::rng(<span class="number">118</span>); + + <span class="kw">let </span><span class="kw-2">mut </span>empty: [u32; <span class="number">0</span>] = []; + <span class="kw">let </span>res = empty.partial_shuffle(<span class="kw-2">&mut </span>r, <span class="number">10</span>); + <span class="macro">assert_eq!</span>((res.<span class="number">0</span>.len(), res.<span class="number">1</span>.len()), (<span class="number">0</span>, <span class="number">0</span>)); + + <span class="kw">let </span><span class="kw-2">mut </span>v = [<span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>]; + <span class="kw">let </span>res = v.partial_shuffle(<span class="kw-2">&mut </span>r, <span class="number">2</span>); + <span class="macro">assert_eq!</span>((res.<span class="number">0</span>.len(), res.<span class="number">1</span>.len()), (<span class="number">2</span>, <span class="number">3</span>)); + <span class="macro">assert!</span>(res.<span class="number">0</span>[<span class="number">0</span>] != res.<span class="number">0</span>[<span class="number">1</span>]); + <span class="comment">// First elements are only modified if selected, so at least one isn't modified: + </span><span class="macro">assert!</span>(res.<span class="number">1</span>[<span class="number">0</span>] == <span class="number">1 </span>|| res.<span class="number">1</span>[<span class="number">1</span>] == <span class="number">2 </span>|| res.<span class="number">1</span>[<span class="number">2</span>] == <span class="number">3</span>); + } + + <span class="attribute">#[test] + #[cfg(feature = <span class="string">"alloc"</span>)] + </span><span class="kw">fn </span>test_sample_iter() { + <span class="kw">let </span>min_val = <span class="number">1</span>; + <span class="kw">let </span>max_val = <span class="number">100</span>; + + <span class="kw">let </span><span class="kw-2">mut </span>r = <span class="kw">crate</span>::test::rng(<span class="number">401</span>); + <span class="kw">let </span>vals = (min_val..max_val).collect::<Vec<i32>>(); + <span class="kw">let </span>small_sample = vals.iter().choose_multiple(<span class="kw-2">&mut </span>r, <span class="number">5</span>); + <span class="kw">let </span>large_sample = vals.iter().choose_multiple(<span class="kw-2">&mut </span>r, vals.len() + <span class="number">5</span>); + + <span class="macro">assert_eq!</span>(small_sample.len(), <span class="number">5</span>); + <span class="macro">assert_eq!</span>(large_sample.len(), vals.len()); + <span class="comment">// no randomization happens when amount >= len + </span><span class="macro">assert_eq!</span>(large_sample, vals.iter().collect::<Vec<<span class="kw">_</span>>>()); + + <span class="macro">assert!</span>(small_sample + .iter() + .all(|e| { <span class="kw-2">**</span>e >= min_val && <span class="kw-2">**</span>e <= max_val })); + } + + <span class="attribute">#[test] + #[cfg(feature = <span class="string">"alloc"</span>)] + #[cfg_attr(miri, ignore)] </span><span class="comment">// Miri is too slow + </span><span class="kw">fn </span>test_weighted() { + <span class="kw">let </span><span class="kw-2">mut </span>r = <span class="kw">crate</span>::test::rng(<span class="number">406</span>); + <span class="kw">const </span>N_REPS: u32 = <span class="number">3000</span>; + <span class="kw">let </span>weights = [<span class="number">1u32</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">0</span>, <span class="number">5</span>, <span class="number">6</span>, <span class="number">7</span>, <span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>, <span class="number">6</span>, <span class="number">7</span>]; + <span class="kw">let </span>total_weight = weights.iter().sum::<u32>() <span class="kw">as </span>f32; + + <span class="kw">let </span>verify = |result: [i32; <span class="number">14</span>]| { + <span class="kw">for </span>(i, count) <span class="kw">in </span>result.iter().enumerate() { + <span class="kw">let </span>exp = (weights[i] * N_REPS) <span class="kw">as </span>f32 / total_weight; + <span class="kw">let </span><span class="kw-2">mut </span>err = (<span class="kw-2">*</span>count <span class="kw">as </span>f32 - exp).abs(); + <span class="kw">if </span>err != <span class="number">0.0 </span>{ + err /= exp; + } + <span class="macro">assert!</span>(err <= <span class="number">0.25</span>); + } + }; + + <span class="comment">// choose_weighted + </span><span class="kw">fn </span>get_weight<T>(item: <span class="kw-2">&</span>(u32, T)) -> u32 { + item.<span class="number">0 + </span>} + <span class="kw">let </span><span class="kw-2">mut </span>chosen = [<span class="number">0i32</span>; <span class="number">14</span>]; + <span class="kw">let </span><span class="kw-2">mut </span>items = [(<span class="number">0u32</span>, <span class="number">0usize</span>); <span class="number">14</span>]; <span class="comment">// (weight, index) + </span><span class="kw">for </span>(i, item) <span class="kw">in </span>items.iter_mut().enumerate() { + <span class="kw-2">*</span>item = (weights[i], i); + } + <span class="kw">for _ in </span><span class="number">0</span>..N_REPS { + <span class="kw">let </span>item = items.choose_weighted(<span class="kw-2">&mut </span>r, get_weight).unwrap(); + chosen[item.<span class="number">1</span>] += <span class="number">1</span>; + } + verify(chosen); + + <span class="comment">// choose_weighted_mut + </span><span class="kw">let </span><span class="kw-2">mut </span>items = [(<span class="number">0u32</span>, <span class="number">0i32</span>); <span class="number">14</span>]; <span class="comment">// (weight, count) + </span><span class="kw">for </span>(i, item) <span class="kw">in </span>items.iter_mut().enumerate() { + <span class="kw-2">*</span>item = (weights[i], <span class="number">0</span>); + } + <span class="kw">for _ in </span><span class="number">0</span>..N_REPS { + items.choose_weighted_mut(<span class="kw-2">&mut </span>r, get_weight).unwrap().<span class="number">1 </span>+= <span class="number">1</span>; + } + <span class="kw">for </span>(ch, item) <span class="kw">in </span>chosen.iter_mut().zip(items.iter()) { + <span class="kw-2">*</span>ch = item.<span class="number">1</span>; + } + verify(chosen); + + <span class="comment">// Check error cases + </span><span class="kw">let </span>empty_slice = <span class="kw-2">&mut </span>[<span class="number">10</span>][<span class="number">0</span>..<span class="number">0</span>]; + <span class="macro">assert_eq!</span>( + empty_slice.choose_weighted(<span class="kw-2">&mut </span>r, |<span class="kw">_</span>| <span class="number">1</span>), + <span class="prelude-val">Err</span>(WeightedError::NoItem) + ); + <span class="macro">assert_eq!</span>( + empty_slice.choose_weighted_mut(<span class="kw-2">&mut </span>r, |<span class="kw">_</span>| <span class="number">1</span>), + <span class="prelude-val">Err</span>(WeightedError::NoItem) + ); + <span class="macro">assert_eq!</span>( + [<span class="string">'x'</span>].choose_weighted_mut(<span class="kw-2">&mut </span>r, |<span class="kw">_</span>| <span class="number">0</span>), + <span class="prelude-val">Err</span>(WeightedError::AllWeightsZero) + ); + <span class="macro">assert_eq!</span>( + [<span class="number">0</span>, -<span class="number">1</span>].choose_weighted_mut(<span class="kw-2">&mut </span>r, |x| <span class="kw-2">*</span>x), + <span class="prelude-val">Err</span>(WeightedError::InvalidWeight) + ); + <span class="macro">assert_eq!</span>( + [-<span class="number">1</span>, <span class="number">0</span>].choose_weighted_mut(<span class="kw-2">&mut </span>r, |x| <span class="kw-2">*</span>x), + <span class="prelude-val">Err</span>(WeightedError::InvalidWeight) + ); + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>value_stability_choose() { + <span class="kw">fn </span>choose<I: Iterator<Item = u32>>(iter: I) -> <span class="prelude-ty">Option</span><u32> { + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">411</span>); + iter.choose(<span class="kw-2">&mut </span>rng) + } + + <span class="macro">assert_eq!</span>(choose([].iter().cloned()), <span class="prelude-val">None</span>); + <span class="macro">assert_eq!</span>(choose(<span class="number">0</span>..<span class="number">100</span>), <span class="prelude-val">Some</span>(<span class="number">33</span>)); + <span class="macro">assert_eq!</span>(choose(UnhintedIterator { iter: <span class="number">0</span>..<span class="number">100 </span>}), <span class="prelude-val">Some</span>(<span class="number">40</span>)); + <span class="macro">assert_eq!</span>( + choose(ChunkHintedIterator { + iter: <span class="number">0</span>..<span class="number">100</span>, + chunk_size: <span class="number">32</span>, + chunk_remaining: <span class="number">32</span>, + hint_total_size: <span class="bool-val">false</span>, + }), + <span class="prelude-val">Some</span>(<span class="number">39</span>) + ); + <span class="macro">assert_eq!</span>( + choose(ChunkHintedIterator { + iter: <span class="number">0</span>..<span class="number">100</span>, + chunk_size: <span class="number">32</span>, + chunk_remaining: <span class="number">32</span>, + hint_total_size: <span class="bool-val">true</span>, + }), + <span class="prelude-val">Some</span>(<span class="number">39</span>) + ); + <span class="macro">assert_eq!</span>( + choose(WindowHintedIterator { + iter: <span class="number">0</span>..<span class="number">100</span>, + window_size: <span class="number">32</span>, + hint_total_size: <span class="bool-val">false</span>, + }), + <span class="prelude-val">Some</span>(<span class="number">90</span>) + ); + <span class="macro">assert_eq!</span>( + choose(WindowHintedIterator { + iter: <span class="number">0</span>..<span class="number">100</span>, + window_size: <span class="number">32</span>, + hint_total_size: <span class="bool-val">true</span>, + }), + <span class="prelude-val">Some</span>(<span class="number">90</span>) + ); + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>value_stability_choose_stable() { + <span class="kw">fn </span>choose<I: Iterator<Item = u32>>(iter: I) -> <span class="prelude-ty">Option</span><u32> { + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">411</span>); + iter.choose_stable(<span class="kw-2">&mut </span>rng) + } + + <span class="macro">assert_eq!</span>(choose([].iter().cloned()), <span class="prelude-val">None</span>); + <span class="macro">assert_eq!</span>(choose(<span class="number">0</span>..<span class="number">100</span>), <span class="prelude-val">Some</span>(<span class="number">40</span>)); + <span class="macro">assert_eq!</span>(choose(UnhintedIterator { iter: <span class="number">0</span>..<span class="number">100 </span>}), <span class="prelude-val">Some</span>(<span class="number">40</span>)); + <span class="macro">assert_eq!</span>( + choose(ChunkHintedIterator { + iter: <span class="number">0</span>..<span class="number">100</span>, + chunk_size: <span class="number">32</span>, + chunk_remaining: <span class="number">32</span>, + hint_total_size: <span class="bool-val">false</span>, + }), + <span class="prelude-val">Some</span>(<span class="number">40</span>) + ); + <span class="macro">assert_eq!</span>( + choose(ChunkHintedIterator { + iter: <span class="number">0</span>..<span class="number">100</span>, + chunk_size: <span class="number">32</span>, + chunk_remaining: <span class="number">32</span>, + hint_total_size: <span class="bool-val">true</span>, + }), + <span class="prelude-val">Some</span>(<span class="number">40</span>) + ); + <span class="macro">assert_eq!</span>( + choose(WindowHintedIterator { + iter: <span class="number">0</span>..<span class="number">100</span>, + window_size: <span class="number">32</span>, + hint_total_size: <span class="bool-val">false</span>, + }), + <span class="prelude-val">Some</span>(<span class="number">40</span>) + ); + <span class="macro">assert_eq!</span>( + choose(WindowHintedIterator { + iter: <span class="number">0</span>..<span class="number">100</span>, + window_size: <span class="number">32</span>, + hint_total_size: <span class="bool-val">true</span>, + }), + <span class="prelude-val">Some</span>(<span class="number">40</span>) + ); + } + + <span class="attribute">#[test] + </span><span class="kw">fn </span>value_stability_choose_multiple() { + <span class="kw">fn </span>do_test<I: Iterator<Item = u32>>(iter: I, v: <span class="kw-2">&</span>[u32]) { + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">412</span>); + <span class="kw">let </span><span class="kw-2">mut </span>buf = [<span class="number">0u32</span>; <span class="number">8</span>]; + <span class="macro">assert_eq!</span>(iter.choose_multiple_fill(<span class="kw-2">&mut </span>rng, <span class="kw-2">&mut </span>buf), v.len()); + <span class="macro">assert_eq!</span>(<span class="kw-2">&</span>buf[<span class="number">0</span>..v.len()], v); + } + + do_test(<span class="number">0</span>..<span class="number">4</span>, <span class="kw-2">&</span>[<span class="number">0</span>, <span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>]); + do_test(<span class="number">0</span>..<span class="number">8</span>, <span class="kw-2">&</span>[<span class="number">0</span>, <span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>, <span class="number">6</span>, <span class="number">7</span>]); + do_test(<span class="number">0</span>..<span class="number">100</span>, <span class="kw-2">&</span>[<span class="number">58</span>, <span class="number">78</span>, <span class="number">80</span>, <span class="number">92</span>, <span class="number">43</span>, <span class="number">8</span>, <span class="number">96</span>, <span class="number">7</span>]); + + <span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] + </span>{ + <span class="kw">fn </span>do_test<I: Iterator<Item = u32>>(iter: I, v: <span class="kw-2">&</span>[u32]) { + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">412</span>); + <span class="macro">assert_eq!</span>(iter.choose_multiple(<span class="kw-2">&mut </span>rng, v.len()), v); + } + + do_test(<span class="number">0</span>..<span class="number">4</span>, <span class="kw-2">&</span>[<span class="number">0</span>, <span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>]); + do_test(<span class="number">0</span>..<span class="number">8</span>, <span class="kw-2">&</span>[<span class="number">0</span>, <span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>, <span class="number">6</span>, <span class="number">7</span>]); + do_test(<span class="number">0</span>..<span class="number">100</span>, <span class="kw-2">&</span>[<span class="number">58</span>, <span class="number">78</span>, <span class="number">80</span>, <span class="number">92</span>, <span class="number">43</span>, <span class="number">8</span>, <span class="number">96</span>, <span class="number">7</span>]); + } + } + + <span class="attribute">#[test] + #[cfg(feature = <span class="string">"std"</span>)] + </span><span class="kw">fn </span>test_multiple_weighted_edge_cases() { + <span class="kw">use super</span>::<span class="kw-2">*</span>; + + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">413</span>); + + <span class="comment">// Case 1: One of the weights is 0 + </span><span class="kw">let </span>choices = [(<span class="string">'a'</span>, <span class="number">2</span>), (<span class="string">'b'</span>, <span class="number">1</span>), (<span class="string">'c'</span>, <span class="number">0</span>)]; + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">100 </span>{ + <span class="kw">let </span>result = choices + .choose_multiple_weighted(<span class="kw-2">&mut </span>rng, <span class="number">2</span>, |item| item.<span class="number">1</span>) + .unwrap() + .collect::<Vec<<span class="kw">_</span>>>(); + + <span class="macro">assert_eq!</span>(result.len(), <span class="number">2</span>); + <span class="macro">assert!</span>(!result.iter().any(|val| val.<span class="number">0 </span>== <span class="string">'c'</span>)); + } + + <span class="comment">// Case 2: All of the weights are 0 + </span><span class="kw">let </span>choices = [(<span class="string">'a'</span>, <span class="number">0</span>), (<span class="string">'b'</span>, <span class="number">0</span>), (<span class="string">'c'</span>, <span class="number">0</span>)]; + + <span class="macro">assert_eq!</span>(choices + .choose_multiple_weighted(<span class="kw-2">&mut </span>rng, <span class="number">2</span>, |item| item.<span class="number">1</span>) + .unwrap().count(), <span class="number">2</span>); + + <span class="comment">// Case 3: Negative weights + </span><span class="kw">let </span>choices = [(<span class="string">'a'</span>, -<span class="number">1</span>), (<span class="string">'b'</span>, <span class="number">1</span>), (<span class="string">'c'</span>, <span class="number">1</span>)]; + <span class="macro">assert_eq!</span>( + choices + .choose_multiple_weighted(<span class="kw-2">&mut </span>rng, <span class="number">2</span>, |item| item.<span class="number">1</span>) + .unwrap_err(), + WeightedError::InvalidWeight + ); + + <span class="comment">// Case 4: Empty list + </span><span class="kw">let </span>choices = []; + <span class="macro">assert_eq!</span>(choices + .choose_multiple_weighted(<span class="kw-2">&mut </span>rng, <span class="number">0</span>, |<span class="kw">_</span>: <span class="kw-2">&</span>()| <span class="number">0</span>) + .unwrap().count(), <span class="number">0</span>); + + <span class="comment">// Case 5: NaN weights + </span><span class="kw">let </span>choices = [(<span class="string">'a'</span>, core::f64::NAN), (<span class="string">'b'</span>, <span class="number">1.0</span>), (<span class="string">'c'</span>, <span class="number">1.0</span>)]; + <span class="macro">assert_eq!</span>( + choices + .choose_multiple_weighted(<span class="kw-2">&mut </span>rng, <span class="number">2</span>, |item| item.<span class="number">1</span>) + .unwrap_err(), + WeightedError::InvalidWeight + ); + + <span class="comment">// Case 6: +infinity weights + </span><span class="kw">let </span>choices = [(<span class="string">'a'</span>, core::f64::INFINITY), (<span class="string">'b'</span>, <span class="number">1.0</span>), (<span class="string">'c'</span>, <span class="number">1.0</span>)]; + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">100 </span>{ + <span class="kw">let </span>result = choices + .choose_multiple_weighted(<span class="kw-2">&mut </span>rng, <span class="number">2</span>, |item| item.<span class="number">1</span>) + .unwrap() + .collect::<Vec<<span class="kw">_</span>>>(); + <span class="macro">assert_eq!</span>(result.len(), <span class="number">2</span>); + <span class="macro">assert!</span>(result.iter().any(|val| val.<span class="number">0 </span>== <span class="string">'a'</span>)); + } + + <span class="comment">// Case 7: -infinity weights + </span><span class="kw">let </span>choices = [(<span class="string">'a'</span>, core::f64::NEG_INFINITY), (<span class="string">'b'</span>, <span class="number">1.0</span>), (<span class="string">'c'</span>, <span class="number">1.0</span>)]; + <span class="macro">assert_eq!</span>( + choices + .choose_multiple_weighted(<span class="kw-2">&mut </span>rng, <span class="number">2</span>, |item| item.<span class="number">1</span>) + .unwrap_err(), + WeightedError::InvalidWeight + ); + + <span class="comment">// Case 8: -0 weights + </span><span class="kw">let </span>choices = [(<span class="string">'a'</span>, -<span class="number">0.0</span>), (<span class="string">'b'</span>, <span class="number">1.0</span>), (<span class="string">'c'</span>, <span class="number">1.0</span>)]; + <span class="macro">assert!</span>(choices + .choose_multiple_weighted(<span class="kw-2">&mut </span>rng, <span class="number">2</span>, |item| item.<span class="number">1</span>) + .is_ok()); + } + + <span class="attribute">#[test] + #[cfg(feature = <span class="string">"std"</span>)] + </span><span class="kw">fn </span>test_multiple_weighted_distributions() { + <span class="kw">use super</span>::<span class="kw-2">*</span>; + + <span class="comment">// The theoretical probabilities of the different outcomes are: + // AB: 0.5 * 0.5 = 0.250 + // AC: 0.5 * 0.5 = 0.250 + // BA: 0.25 * 0.67 = 0.167 + // BC: 0.25 * 0.33 = 0.082 + // CA: 0.25 * 0.67 = 0.167 + // CB: 0.25 * 0.33 = 0.082 + </span><span class="kw">let </span>choices = [(<span class="string">'a'</span>, <span class="number">2</span>), (<span class="string">'b'</span>, <span class="number">1</span>), (<span class="string">'c'</span>, <span class="number">1</span>)]; + <span class="kw">let </span><span class="kw-2">mut </span>rng = <span class="kw">crate</span>::test::rng(<span class="number">414</span>); + + <span class="kw">let </span><span class="kw-2">mut </span>results = [<span class="number">0i32</span>; <span class="number">3</span>]; + <span class="kw">let </span>expected_results = [<span class="number">4167</span>, <span class="number">4167</span>, <span class="number">1666</span>]; + <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">10000 </span>{ + <span class="kw">let </span>result = choices + .choose_multiple_weighted(<span class="kw-2">&mut </span>rng, <span class="number">2</span>, |item| item.<span class="number">1</span>) + .unwrap() + .collect::<Vec<<span class="kw">_</span>>>(); + + <span class="macro">assert_eq!</span>(result.len(), <span class="number">2</span>); + + <span class="kw">match </span>(result[<span class="number">0</span>].<span class="number">0</span>, result[<span class="number">1</span>].<span class="number">0</span>) { + (<span class="string">'a'</span>, <span class="string">'b'</span>) | (<span class="string">'b'</span>, <span class="string">'a'</span>) => { + results[<span class="number">0</span>] += <span class="number">1</span>; + } + (<span class="string">'a'</span>, <span class="string">'c'</span>) | (<span class="string">'c'</span>, <span class="string">'a'</span>) => { + results[<span class="number">1</span>] += <span class="number">1</span>; + } + (<span class="string">'b'</span>, <span class="string">'c'</span>) | (<span class="string">'c'</span>, <span class="string">'b'</span>) => { + results[<span class="number">2</span>] += <span class="number">1</span>; + } + (<span class="kw">_</span>, <span class="kw">_</span>) => <span class="macro">panic!</span>(<span class="string">"unexpected result"</span>), + } + } + + <span class="kw">let </span><span class="kw-2">mut </span>diffs = results + .iter() + .zip(<span class="kw-2">&</span>expected_results) + .map(|(a, b)| (a - b).abs()); + <span class="macro">assert!</span>(!diffs.any(|deviation| deviation > <span class="number">100</span>)); + } +} +</code></pre></div> +</section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="rand" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0 (69f9c33d7 2022-12-12) (Arch Linux rust 1:1.66.0-1)" ></div></body></html>
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