update at 2020-06-21 19:00:26 by ehlxr

Cargo.lock

@@ -1,58 +1,6 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-[[package]]
-name = "hello_macro"
-version = "0.1.0"
-
-[[package]]
-name = "hello_macro_derive"
-version = "0.1.0"
-dependencies = [
- "quote 0.6.13 (registry+https://github.com/rust-lang/crates.io-index)",
- "syn 0.14.9 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "proc-macro2"
-version = "0.4.30"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "unicode-xid 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "quote"
-version = "0.6.13"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "proc-macro2 0.4.30 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
 [[package]]
 name = "rust_study"
 version = "0.1.0"
-dependencies = [
- "hello_macro 0.1.0",
- "hello_macro_derive 0.1.0",
-]
 
-[[package]]
-name = "syn"
-version = "0.14.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "proc-macro2 0.4.30 (registry+https://github.com/rust-lang/crates.io-index)",
- "quote 0.6.13 (registry+https://github.com/rust-lang/crates.io-index)",
- "unicode-xid 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "unicode-xid"
-version = "0.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
-[metadata]
-"checksum proc-macro2 0.4.30 (registry+https://github.com/rust-lang/crates.io-index)" = "cf3d2011ab5c909338f7887f4fc896d35932e29146c12c8d01da6b22a80ba759"
-"checksum quote 0.6.13 (registry+https://github.com/rust-lang/crates.io-index)" = "6ce23b6b870e8f94f81fb0a363d65d86675884b34a09043c81e5562f11c1f8e1"
-"checksum syn 0.14.9 (registry+https://github.com/rust-lang/crates.io-index)" = "261ae9ecaa397c42b960649561949d69311f08eeaea86a65696e6e46517cf741"
-"checksum unicode-xid 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "fc72304796d0818e357ead4e000d19c9c174ab23dc11093ac919054d20a6a7fc"

Cargo.toml

@@ -5,5 +5,5 @@ authors = ["ehlxr <ehlxr.me@gmail.com>"]
 edition = "2018"
 
 [dependencies]
-hello_macro = { path = "../hello_macro" }
+# hello_macro = { path = "../hello_macro" }
-hello_macro_derive = { path = "../hello_macro/hello_macro_derive" }
+# hello_macro_derive = { path = "../hello_macro/hello_macro_derive" }

hello.txt

@@ -1 +0,0 @@
-ehlxr

src/main.rs

@@ -917,13 +917,13 @@ fn main() {
 
     // ---------------------------
     println!("---------------------------");
-    use hello_macro::HelloMacro;
+    // use hello_macro::HelloMacro;
-    use hello_macro_derive::HelloMacro;
+    // use hello_macro_derive::HelloMacro;
 
-    #[derive(HelloMacro)]
+    // #[derive(HelloMacro)]
-    struct Pancakes;
+    // struct Pancakes;
 
-    Pancakes::hello_macro();
+    // Pancakes::hello_macro();
 
     let user1 = User {
         username: String::from("hllo"),
@@ -962,7 +962,86 @@ fn main() {
     println!("");
     // let s = hello[1]; // Rust 的字符串不支持索引
     // let s = &hello[0..4]; // thread 'main' panicked at 'byte index 4 is not a char boundary; it is inside '试' (bytes 3..6) of `测试中文字符串`', src/libcore/str/mod.rs:2219:5
-    print!("{}", &hello[0..3]);
+    println!("{}", &hello[0..3]);
+
+    println!("--------------HashMap-----------");
+
+    let mut scores = HashMap::new();
+    scores.insert(String::from("Blue"), 10);
+    scores.insert(String::from("Yellow"), 50);
+    println!("{:?}", scores);
+    for (k, v) in &scores {
+        println!("k {}, v {}", k, v);
+    }
+    // 只在键没有对应值时插入
+    // Entry 的 or_insert 方法在键对应的值存在时就返回这个值的 Entry ，
+    // 如果不存在则将参数作为新值插入并返回修改过的 Entry
+    let x3 = scores.entry("Blue".to_string()).or_insert(60);
+    println!("{}", x3);
+    let x2 = scores.entry("Red".to_string()).or_insert(55);
+    println!("{}", x2);
+    println!("{:?}", scores);
+
+    let nms = vec![String::from("Blue"), String::from("Yellow")];
+    let scs = vec![10, 50];
+    let scores: HashMap<_, _> = nms.iter().zip(scs.iter()).collect();
+    println!("{:?}", scores);
+
+    let field_name = String::from("hello");
+    let field_value = 456;
+    let mut map1 = HashMap::new();
+    map1.insert(field_name, field_value);
+    // borrow of moved value: `field_name`
+    // println!("{} {} {:?}", field_name, field_value, map1);
+    println!("{} {:?}", field_value, map1);
+
+    let k = &String::from("hello");
+    let v = String::from("world");
+    let mut map1 = HashMap::new();
+    map1.insert(k, v);
+    // borrow of moved value: `v`
+    // println!("{} {} {:?}", k, v, map1);
+    println!("{} {:?}", *k, map1);
+
+    let option = map1.get(k);
+    println!("{}", option.unwrap());
+
+    let text = "hello world wonderful world";
+    let mut map = HashMap::new();
+    for tex in text.split_whitespace() {
+        let counts = map.entry(tex).or_insert(0);
+        *counts += 1;
+    }
+    println!("{:?}", map);
+
+    println!("----------------错误处理-----------------");
+    let fnames = "hello2.txt";
+    let result = File::open(fnames);
+    let file = match result {
+        Ok(f) => f,
+        // Err(e) => {
+        //     println!("Problem opening the file: {:?}", e);
+        //
+        //     File::create(fnames).unwrap()
+        // }
+        Err(e) => match e.kind() {
+            ErrorKind::NotFound => {
+                match File::create(fnames) {
+                    Ok(f) => f,
+                    Err(e) => panic!("Problem creating the file: {:?}", e),
+                }
+            }
+            oe => panic!("Problem opening the file: {:?}", oe),
+        }
+    };
+    println!("{:?}", file);
+
+    println!("----------------match 匹配 枚举------------------");
+    let m = Message::Quit;
+    match m {
+        Message::Write(s) => println!("{}", s),
+        abc => println!("{:?}", abc),
+    }
 }
 
 fn test_tuple(t: (i32, &str)) {
@@ -1268,7 +1347,7 @@ impl ToString for Tweet {
 //}
 
 fn notify<T, U>(t: &T, u: &U) -> String
-where
+    where
         T: Summary + ToString,
         U: Summary,
 {
@@ -1338,7 +1417,7 @@ fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
 }
 
 struct Cacher<T, D, F>
-where
+    where
         T: Fn(&D) -> F,
 {
     calculation: T,
@@ -1346,7 +1425,7 @@ where
 }
 
 impl<T, D, F> Cacher<T, D, F>
-where
+    where
         D: Hash + Eq,
         F: Copy,
         T: Fn(&D) -> F,