add 14.2

xcy-solutions/14. 包和模块/14.2/hello-package/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "hello-package"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

xcy-solutions/14. 包和模块/14.2/hello-package/src/lib.rs

@@ -0,0 +1,50 @@
+pub fn add(left: u64, right: u64) -> u64 {
+    left + right
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn it_works() {
+        let result = add(2, 2);
+        assert_eq!(result, 4);
+    }
+}
+
+mod front_of_house {
+    pub mod hosting {
+        pub fn add_to_waitlist() {}
+        fn seat_at_table() {}
+    }
+    pub mod serving {
+        fn take_order() {}
+        pub fn serve_order() {}
+        fn take_payment() {}
+        fn complain() {}
+    }
+}
+
+fn eat_at_restaurant() {
+    // 使用绝对路径调用
+    crate::front_of_house::hosting::add_to_waitlist();
+
+    // 使用相对路径调用
+    front_of_house::hosting::add_to_waitlist();
+}
+
+// in lib.rs
+
+mod back_of_house {
+    fn fix_incorrect_order() {
+        cook_order();
+        // 使用2种方式填空
+        //1. 使用关键字 `super`
+        //2. 使用绝对路径
+        crate::front_of_house::serving::serve_order();
+        super::front_of_house::serving::serve_order();
+    }
+
+    fn cook_order() {}
+}

xcy-solutions/14. 包和模块/14.2/hello-package4/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "hello-package4"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

xcy-solutions/14. 包和模块/14.2/hello-package4/src/back_of_house.rs

@@ -0,0 +1,6 @@
+pub fn fix_incorrect_order() {
+    cook_order();
+    crate::front_of_house::serving::serve_order();
+}
+
+pub fn cook_order() {}

xcy-solutions/14. 包和模块/14.2/hello-package4/src/front_of_house/hosting.rs

@@ -0,0 +1,5 @@
+pub fn add_to_waitlist() {}
+
+pub fn seat_at_table() -> String {
+    String::from("sit down please")
+}

xcy-solutions/14. 包和模块/14.2/hello-package4/src/front_of_house/mod.rs

@@ -0,0 +1,2 @@
+pub mod hosting;
+pub mod serving;

xcy-solutions/14. 包和模块/14.2/hello-package4/src/front_of_house/serving.rs

@@ -0,0 +1,8 @@
+pub fn take_order() {}
+
+pub fn serve_order() {}
+
+pub fn take_payment() {}
+
+// 我猜你不希望顾客听到你在抱怨他们，因此让这个函数私有化吧
+fn complain() {}

xcy-solutions/14. 包和模块/14.2/hello-package4/src/lib.rs

@@ -0,0 +1,12 @@
+// in lib.rs
+mod front_of_house;
+mod back_of_house;
+
+
+pub fn eat_at_restaurant() -> String {
+    front_of_house::hosting::add_to_waitlist();
+
+    back_of_house::cook_order();
+
+    String::from("yummy yummy!")
+}

xcy-solutions/14. 包和模块/14.2/hello-package4/src/main.rs

@@ -0,0 +1,17 @@
+// // in src/main.rs
+//
+// // 填空并修复错误
+// fn main() {
+//     assert_eq!(__, "sit down please");
+//     assert_eq!(__,"yummy yummy!");
+// }
+
+// in src/main.rs
+
+mod front_of_house;
+
+// 填空并修复错误
+fn main() {
+    assert_eq!(front_of_house::hosting::seat_at_table(), "sit down please");
+    assert_eq!(hello_package4::eat_at_restaurant(),"yummy yummy!");
+}

xcy-solutions/14. 包和模块/14.2/main1.txt

@@ -0,0 +1,6 @@
+// 填空
+// in lib.rs
+
+mod front_of_house {
+    // 实现此模块
+}