enums1.rs

// enums1.rs
//
// No hints this time! ;)

#[derive(Debug)]
enum Message {
    Quit,
    Echo,
    Move,
    ChangeColor,
}

fn main() {
    println!("{:?}", Message::Quit);
    println!("{:?}", Message::Echo);
    println!("{:?}", Message::Move);
    println!("{:?}", Message::ChangeColor);
}

enums2.rs

// enums2.rs
//
// Execute `rustlings hint enums2` or use the `hint` watch subcommand for a
// hint.

#[derive(Debug)]
enum Message {
    Move { x: i32, y: i32 },
    Echo(String),
    ChangeColor(i32, i32, i32),
    Quit,
}

impl Message {
    fn call(&self) {
        println!("{:?}", self);
    }
}

fn main() {
    let messages = [
        Message::Move { x: 10, y: 30 },
        Message::Echo(String::from("hello world")),
        Message::ChangeColor(200, 255, 255),
        Message::Quit,
    ];

    for message in &messages {
        message.call();
    }
}

enums3.rs

// enums3.rs
//
// Address all the TODOs to make the tests pass!
//
// Execute `rustlings hint enums3` or use the `hint` watch subcommand for a
// hint.

enum Message {
    Move(Point),
    Echo(String),
    ChangeColor(u8, u8, u8),
    Quit,
}

struct Point {
    x: u8,
    y: u8,
}

struct State {
    color: (u8, u8, u8),
    position: Point,
    quit: bool,
    message: String,
}

impl State {
    fn change_color(&mut self, color: (u8, u8, u8)) {
        self.color = color;
    }

    fn quit(&mut self) {
        self.quit = true;
    }

    fn echo(&mut self, s: String) {
        self.message = s
    }

    fn move_position(&mut self, p: Point) {
        self.position = p;
    }

    fn process(&mut self, message: Message) {
        match message {
            Message::ChangeColor(r, g, b) => self.change_color((r, g, b)),
            Message::Quit => self.quit(),
            Message::Echo(s) => self.echo(s),
            Message::Move(p) => self.move_position(p),
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_match_message_call() {
        let mut state = State {
            quit: false,
            position: Point { x: 0, y: 0 },
            color: (0, 0, 0),
            message: "hello world".to_string(),
        };
        state.process(Message::ChangeColor(255, 0, 255));
        state.process(Message::Echo(String::from("Hello world!")));
        state.process(Message::Move(Point { x: 10, y: 15 }));
        state.process(Message::Quit);

        assert_eq!(state.color, (255, 0, 255));
        assert_eq!(state.position.x, 10);
        assert_eq!(state.position.y, 15);
        assert_eq!(state.quit, true);
        assert_eq!(state.message, "Hello world!");
    }
}