Mario

mario.rs

// SUPER-MARIO STATE MACHINE IN RUST

#[derive(Debug, PartialEq)]
enum State {
    Mario,
    SuperMario,
    FireMario,
    CapeMario,
}

use State::*;


#[derive(Debug)]
enum Transition {
    Feather,
    Flower,
    Mushroom,
}

use Transition::*;


#[derive(Debug)]
struct Player {
    state: State
}

impl Player {
    fn new () -> Self {
        Self {state: Mario}
    }

    fn collect(&mut self, power: Transition) {
        match (&self.state, power) {
            (Mario, Mushroom) => self.state = SuperMario,
            (_, Feather) => self.state = CapeMario,
            (_, Flower) => self.state = FireMario,
            (_, Mushroom) => {}
        }
    }
}


fn main() {
    let mut player = Player::new();
    player.collect(Mushroom); // Mario -> SuperMario
    player.collect(Flower); // SuperMario -> FireMario
    player.collect(Feather); // FireMario -> CapeMario
    player.collect(Mushroom); // No Effect
    player.collect(Mushroom); // No Effect

    assert!(player.state == CapeMario)
}