closure and iterator

1 files changed, 46 insertions, 0 deletions

diff --git a/rust/theBook/chapter-13-functional-language-features-iterators-and-closures/shirt_inventory/src/main.rs b/rust/theBook/chapter-13-functional-language-features-iterators-and-closures/shirt_inventory/src/main.rs
new file mode 100644
index 0000000..51e1785
--- /dev/null
+++ b/rust/theBook/chapter-13-functional-language-features-iterators-and-closures/shirt_inventory/src/main.rs
@@ -0,0 +1,46 @@
+#[derive(Debug, PartialEq, Copy, Clone)]
+enum ShirtColor {
+    Red,
+    Blue,
+}
+
+struct Inventory {
+    shirts: Vec<ShirtColor>,
+}
+
+impl Inventory {
+    fn giveaway(&self, user_preference: Option<ShirtColor>) -> ShirtColor {
+        user_preference.unwrap_or_else(|| self.most_stocked())
+    }
+
+    fn most_stocked(&self) -> ShirtColor {
+        let mut red_num = 0;
+        let mut blue_num = 0;
+
+        for color in &self.shirts {
+            match color {
+                ShirtColor::Red => red_num += 1,
+                ShirtColor::Blue => blue_num += 1,
+            }
+        }
+        if red_num > blue_num {
+            ShirtColor::Red
+        }   else {
+            ShirtColor::Blue
+        }
+    }
+}
+
+fn main() {
+    let store = Inventory {
+        shirts: vec![ShirtColor::Blue, ShirtColor::Red, ShirtColor::Blue],
+    };
+
+    let user_pref1 = Some(ShirtColor::Red);
+    let giveaway1 = store.giveaway(user_pref1);
+    println!("The user with preference {:?} get {:?}",user_pref1,giveaway1);
+
+    let user_pref2 = None;
+    let giveaway2 = store.giveaway(user_pref2);
+    println!("The user with preference {user_pref2:?} get {:?}", giveaway2);
+}