rust官方的猜字游戲

struct User {
    username :String,
    email:String,
    sign_in_count: u64,
    active:bool,
}

fn build_user(email: String, username: String) -> User {
    User {
        email,
        username,
        active: true,
        sign_in_count: 1,
    }
}

#[derive(Debug)]
struct PPP {
    w: u32,
    h: u32,
}
impl  PPP {
    fn new(w :u32, h :u32) ->  PPP {
         PPP{w:w, h:h}
    }
    fn area(&self) -> u32 {
        self.w * self.h
    }
    fn campare(&self, other: &PPP) -> bool {
        self.area() > other.area()
    }
}


enum IpAddrKind {
    V4,
    V6
}
struct IpAddr {
    kind:IpAddrKind,
    address:String,
}

enum IpAddrV2 {
    V4(u8,u8,u8,u8),
    V6(String),
}



enum Coin {
    Penny,
    Nickel,
    Dime,
    Quarter,
}

fn value_in_cents(coin: Coin) -> u8 {
    match coin {
        Coin::Penny => 1,
        Coin::Nickel => 5,
        Coin::Dime => 10,
        Coin::Quarter => 25,
    }
}

fn main() {

    let x = 123;
    println!("{x}");
    let x = 456;
    println!("{}", x);
    let mut x = 758;
    x = 111;
    println!("{}", x);

    const MAX_POINTS: u32 = 100_000;
    println!("MAX_POINTS:{}", MAX_POINTS);
    
    let y :i64 = 12;
    let mut x :i32 = y as i32;
    x  = 0xff;
    println!("x:{}", x);
    let x :f32 = 12.12;
    println!("{}", x);

    let b:bool = true;
    println!("b={}", b);

    let tup1 :(i32,i64,u8) = (1,2,3);
    println!("tup1={:?}", tup1);
    let arr = [1,2,4,5];
    println!("arr={:?}", arr);
    let arr2 :[f32;5]= [1.1,2.2,2.3,4.1,5.2];
    println!("arr={:?}", arr2);

    //func 
    let x :i32= 123;
    afunc(x);

    println!("func1 {}", addOne(x));

    if x > 3 {
        println!("big then 3");
    }else if (x > 4) {
        println!("small then 4");
    }else {
        println!("small then 3");
    }

    let number = if x > 3  {
        true
    } else {
        false
    };
    println!("number={}", number);

    let mut x = 1;
    loop {
        
        if x > 3 {
            break;
        }
        x = x + 1;
        println!("again!");
    }

    while x < 6 {
        x = x + 1;
        println!("again!");
    }

    for elem in arr.iter() {
        println!("elem={}", elem);
    }

    for elem in (1..4).rev() {
        println!("rev={}", elem);
    }


    {
        let xxx = 1;
        println!("inner xxx={}", xxx);
    }
    //println!("xxx={}", xxx);

    let mut str1 = String::from("hello");
    str1.push_str(" world!");
    println!("{}", str1);
    let str2 = str1;
    println!("str2:{}", str2);
    //clone
    let str3 = str2.clone();
    println!("str2:{}", str2);
    println!("str3:{}", str3);


    let str11 = String::from("hello");
    let str12 = setStr(str11);
    //println!("str11:{}", str11);
    println!("str12:{}", str12);

    /**
     * 在任意給定時間背捌，要么 只能有一個可變引用狐胎，要么 只能有多個不可變引用溪椎。
引用必須總是有效的。
     */
    //add str
    let mut str13 = String::from("abc");
    addStr2(&mut str13);
    println!("str13={}", str13);

    let str14 = &str13[0..5];
    let str15 = &str13[5..8];
    println!("str14={} {}", str14,str15);

    println!("all={}", &str13[..]);

    let user1 = User{
        username :String::from("xxx"),
        email:String::from("xxx@126.com"),
        sign_in_count: 41,
        active:true,
    };

    let user2 = build_user(String::from("xxx"),String::from("xxx@126.com"));
    println!("user1.name={}", user1.username);
    println!("user2.name={}", user2.username);


    struct Color(i32, i32, i32);
    struct Point(i32, i32, i32);
    let black = Color(1, 2, 3);
    let origin = Point(11, 12, 13);
    println!("point1={:?} {:?}", black.0,origin.0);

    let ppp1 = PPP::new(11,12);
    println!("ppp1={:?}, {:?}", ppp1, ppp1.area());

    let ppp2 = PPP::new(12,12);
    println!("ppp2={:?}, {:?}", ppp2, ppp2.area());

    println!("bool={}",ppp1.campare(&ppp2));

    let home = IpAddr {
        kind: IpAddrKind::V4,
        address: String::from("127.0.0.1"),
    };
    println!("home:{}",home.address);
    
    let loopback = IpAddr {
        kind: IpAddrKind::V6,
        address: String::from("::1"),
    };
    println!("home:{}",loopback.address);

    let ipv2 = IpAddrV2::V4(1,2,3,4);

    let some_number = Some(5);
    let some_string = Some("a string");

    let absent_number: Option<i32> = None;

    let coin_one = Coin::Penny;

    let mut count  = 0;
    if let Coin::Penny = coin_one {
        println!("Coin::Penny match");
    } else {
        count += 1;
    }
    println!("count:{}",count);

    let result = value_in_cents(coin_one);
    println!("result:{}",result);

    let some1 = Some(6);
    let some2 = plus_one(some1);
    let none = plus_one(None);

    let some_u8_value = 0u8;
    match some_u8_value {
        1 => println!("one"),
        3 => println!("three"),
        5 => println!("five"),
        7 => println!("seven"),
        _ => (),
    }

}


fn plus_one(x :Option<i32>) -> Option<i32> {
    match x {
        None => None,
        Some(i) => Some(i + 1),
    }
}

fn setStr(str1 : String) -> String{
    str1
}

fn printLen(str :&String) -> usize {
    str.len()
}

fn addStr2(str :&mut String){
    str.push_str(", world");
}


fn afunc(x :i32) {
    println!("func1 {}", x);
}

fn addOne(x :i32) -> i32{
    x + 1
}