From 8f1121ab45de3b99162b7c2c9e835246b59cba04 Mon Sep 17 00:00:00 2001
From: sunface <cto@188.com>
Date: Tue, 1 Mar 2022 20:55:22 +0800
Subject: [PATCH] add patterns.md

---
 src/pattern-match/patterns.md       | 77 +++++++++++++++++++++-
 zh-CN/src/pattern-match/patterns.md | 99 ++++++++++++++++++++++++++++-
 2 files changed, 174 insertions(+), 2 deletions(-)

diff --git a/src/pattern-match/patterns.md b/src/pattern-match/patterns.md
index c3f49b9..2b2d752 100644
--- a/src/pattern-match/patterns.md
+++ b/src/pattern-match/patterns.md
@@ -1,6 +1,6 @@
 # Patterns
 
-🌟🌟 Using `|` to match several values.
+🌟🌟 use `|` to match several values, use `..=` to match a inclusive range
 ```rust,editable
 
 fn main() {}
@@ -21,3 +21,78 @@ fn match_number(n: i32) {
 }
 ```
 
+🌟🌟🌟 The `@` operator lets us create a variable that holds a value at the same time we are testing that value to see whether it matches a pattern.
+```rust,editable
+
+struct Point {
+    x: i32,
+    y: i32,
+}
+
+fn main() {
+    // fill in the blank to let p match the second arm
+    let p = Point { x: __, y: __ };
+
+    match p {
+        Point { x, y: 0 } => println!("On the x axis at {}", x),
+        // second arm
+        Point { x: 0..=5, y: y@ (10 | 20 | 30) } => println!("On the y axis at {}", y),
+        Point { x, y } => println!("On neither axis: ({}, {})", x, y),
+    }
+}
+```
+
+🌟🌟🌟
+
+```rust,editable
+
+// fix the errors
+enum Message {
+    Hello { id: i32 },
+}
+
+fn main() {
+    let msg = Message::Hello { id: 5 };
+
+    match msg {
+        Message::Hello {
+            id:  3..=7,
+        } => println!("Found an id in range [3, 7]: {}", id),
+        Message::Hello { id: newid@10 | 11 | 12 } => {
+            println!("Found an id in another range [10, 12]: {}", newid)
+        }
+        Message::Hello { id } => println!("Found some other id: {}", id),
+    }
+}
+```
+
+🌟🌟 A match guard is an additional if condition specified after the pattern in a match arm that must also match, along with the pattern matching, for that arm to be chosen.
+```rust,editable
+
+// fill in the blank to make the code work, `split` MUST be used
+fn main() {
+    let num = Some(4);
+    let split = 5;
+    match num {
+        Some(x) __ => assert!(x < split),
+        Some(x) => assert!(x >= split),
+        None => (),
+    }
+}
+```
+
+🌟🌟 Ignoring remaining parts of the value with `..`
+```rust,editable
+
+// fill the blank to make the code work
+fn main() {
+    let numbers = (2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048);
+
+    match numbers {
+        __ => {
+           assert_eq!(first, 2);
+           assert_eq!(last, 2048);
+        }
+    }
+}
+```
\ No newline at end of file
diff --git a/zh-CN/src/pattern-match/patterns.md b/zh-CN/src/pattern-match/patterns.md
index 3c9daa3..0894345 100644
--- a/zh-CN/src/pattern-match/patterns.md
+++ b/zh-CN/src/pattern-match/patterns.md
@@ -1 +1,98 @@
-# Patterns
+# 模式
+
+🌟🌟 使用 `|` 可以匹配多个值, 而使用 `..=` 可以匹配一个闭区间的数值序列
+```rust,editable
+
+fn main() {}
+fn match_number(n: i32) {
+    match n {
+        // 匹配一个单独的值
+        1 => println!("One!"),
+        // 使用 `|` 填空，不要使用 `..` 或 `..=`
+        __ => println!("match 2 -> 5"),
+        // 匹配一个闭区间的数值序列
+        6..=10 => {
+            println!("match 6 -> 10")
+        },
+        _ => {
+            println!("match 11 -> +infinite")
+        }
+    }
+}
+```
+
+🌟🌟🌟  `@` 操作符可以让我们将一个与模式相匹配的值绑定到新的变量上
+```rust,editable
+
+struct Point {
+    x: i32,
+    y: i32,
+}
+
+fn main() {
+    // 填空，让 p 匹配第二个分支
+    let p = Point { x: __, y: __ };
+
+    match p {
+        Point { x, y: 0 } => println!("On the x axis at {}", x),
+        // 第二个分支
+        Point { x: 0..=5, y: y@ (10 | 20 | 30) } => println!("On the y axis at {}", y),
+        Point { x, y } => println!("On neither axis: ({}, {})", x, y),
+    }
+}
+```
+
+🌟🌟🌟
+
+```rust,editable
+
+// 修复错误
+enum Message {
+    Hello { id: i32 },
+}
+
+fn main() {
+    let msg = Message::Hello { id: 5 };
+
+    match msg {
+        Message::Hello {
+            id:  3..=7,
+        } => println!("id 值的范围在 [3, 7] 之间: {}", id),
+        Message::Hello { id: newid@10 | 11 | 12 } => {
+            println!("id 值的范围在 [10, 12] 之间: {}", newid)
+        }
+        Message::Hello { id } => println!("Found some other id: {}", id),
+    }
+}
+```
+
+🌟🌟 匹配守卫（match guard）是一个位于 match 分支模式之后的额外 if 条件，它能为分支模式提供更进一步的匹配条件。
+```rust,editable
+
+// 填空让代码工作，必须使用 `split`
+fn main() {
+    let num = Some(4);
+    let split = 5;
+    match num {
+        Some(x) __ => assert!(x < split),
+        Some(x) => assert!(x >= split),
+        None => (),
+    }
+}
+```
+
+🌟🌟🌟 使用 `..` 忽略一部分值
+```rust,editable
+
+// 填空，让代码工作
+fn main() {
+    let numbers = (2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048);
+
+    match numbers {
+        __ => {
+           assert_eq!(first, 2);
+           assert_eq!(last, 2048);
+        }
+    }
+}
+```
\ No newline at end of file