rock-paper-scissors-lizard-spock.rs

use std::error::Error;

#[derive(PartialEq)]
enum MyGameResult {
    Win,
    Lose,
    Tie,
}

#[derive(Debug, PartialEq, Clone, Copy)]
enum Shape {
    Rock = 0,
    Paper = 1,
    Scissors = 2,
    Lizard = 3,
    Spock = 4,
}

impl std::convert::TryFrom<u8> for Shape {
    type Error = Box<dyn Error>;

    fn try_from(value: u8) -> Result<Self, Self::Error>{
        match value {
            0 => Ok(Shape::Rock),
            1 => Ok(Shape::Paper),
            2 => Ok(Shape::Scissors),
            3 => Ok(Shape::Lizard),
            4 => Ok(Shape::Spock),
            _ => Err(format!("invalid shape: {}", value).into()),
        }
    }
}

fn vs(me: Shape, opponent: Shape) -> MyGameResult {
    todo!("implement me");
}

fn main() {

    // Rules from: https://bigbangtheory.fandom.com/wiki/Rock,_Paper,_Scissors,_Lizard,_Spock

    // Wins
    assert!(vs(Shape::Scissors, Shape::Paper) == MyGameResult::Win); // "Scissors cuts Paper"
    assert!(vs(Shape::Paper, Shape::Rock) == MyGameResult::Win); // "Paper covers Rock"
    assert!(vs(Shape::Rock, Shape::Lizard) == MyGameResult::Win); // "Rock crushes Lizard"
    assert!(vs(Shape::Lizard, Shape::Spock) == MyGameResult::Win); // "Lizard poisons Spock"
    assert!(vs(Shape::Spock, Shape::Scissors) == MyGameResult::Win); // "Spock smashes Scissors"
    assert!(vs(Shape::Scissors, Shape::Lizard) == MyGameResult::Win); // "Scissors decapitates Lizard"
    assert!(vs(Shape::Lizard, Shape::Paper) == MyGameResult::Win); // "Lizard eats Paper"
    assert!(vs(Shape::Paper, Shape::Spock) == MyGameResult::Win); // "Paper disproves Spock"
    assert!(vs(Shape::Spock, Shape::Rock) == MyGameResult::Win); // "Spock vaporizes Rock"
    assert!(vs(Shape::Rock, Shape::Scissors) == MyGameResult::Win); // "Rock crushes Scissors"

    // Ties
    assert!(vs(Shape::Rock, Shape::Rock) == MyGameResult::Tie);
    assert!(vs(Shape::Paper, Shape::Paper) == MyGameResult::Tie);
    assert!(vs(Shape::Scissors, Shape::Scissors) == MyGameResult::Tie);
    assert!(vs(Shape::Lizard, Shape::Lizard) == MyGameResult::Tie);
    assert!(vs(Shape::Spock, Shape::Spock) == MyGameResult::Tie);

    // One Example Loss
    assert!(vs(Shape::Scissors, Shape::Rock) == MyGameResult::Lose);

}