#[derive(Debug, Clone)]
enum Msg {
    Quit,
    Move { x: i32, y: i32 },
    Change(i32, i32, i32),
    Error,
}

impl Msg {
    fn show(&self) {
        match self {
            Msg::Quit => println!("quit"),
            Msg::Move { x, y } => println!("move {} {}", x, y),
            Msg::Change(x, y, z) => println!("change {} {} {} ", x, y, z),
            _ => println!("_"),
        }
    }
}
fn main() {
    let q = Msg::Quit;
    q.show();
    let e = Msg::Error;
    e.show();

    let m = Msg::Move { x: 1, y: 2 };
    m.show();

    let c = Msg::Change(1, 2, 3);
    c.show();
}