Update Ch15

projects/limit_tracker/src/lib.rs

@@ -25,14 +25,11 @@ where
 
         let percentage_of_max = self.value as f64 / self.max as f64;
 
-        if percentage_of_max >= 1.0 {
-            self.messenger.send("出错：你已超出你的配额！");
-        } else if percentage_of_max >= 0.9 {
-            self.messenger
-                .send("紧急警告：你已用掉你配额的 90% ！");
-        } else if percentage_of_max >= 0.75 {
-            self.messenger
-                .send("警告：你已用掉你配额的 75% ！");
+        match percentage_of_max {
+            max if max >= 1.0 => self.messenger.send("出错：你已超出你的配额！"),
+            max if max >= 0.9 => self.messenger.send("紧急警告：你已用掉你配额的 90% ！"),
+            max if max >= 0.75 => self.messenger.send("警告：你已用掉你配额的 75% ！"),
+            _ => {},
         }
     }
 }

projects/pattern_syntax_demo/src/main.rs

@@ -10,8 +10,17 @@ fn main() {
             id: id_variable @ 3..=7,
         } => println! ("找到位于范围内的一个 id: {}", id_variable),
         Message::Hello { id: 10..=12 } => {
-            println! ("找到位于另一范围的一个 {}", id);
+            println! ("找到位于另一范围的一个 id");
         },
         Message::Hello { id } => println! ("找到别的一个 id: {}", id),
     }
+
+    let level = 0.8;
+
+    match level {
+        l if l >= 1.0 => println! ("超出额度"),
+        l if l >= 0.9 => println! ("超出 90% 额度"),
+        l if l >= 0.75 => println! ("超出 75% 额度"),
+        _ => (),
+    }
 }