mastermind.rs

#[cfg(test)] // <1>
mod tests {
    // <2>
    use super::*; // <3>

    #[test]
    fn can_evaluate_r_r() {
        // <4>
        assert_eq!(evaluate(vec!(Color::RED), vec!(Color::RED)), (1, 0)) // <5>
    }

    #[test]
    fn can_evaluate_r_r_b_r_r_r() {
        assert_eq!(
            evaluate(
                vec!(Color::RED, Color::RED, Color::BLUE),
                vec!(Color::RED, Color::RED, Color::RED)
            ),
            (2, 0)
        )
    }
}

#[derive(Clone, Debug, PartialEq)] // <1>
pub enum Color {
    RED,
    GREEN,
    BLUE,
    YELLOW,
}

/// Public interface of the evaluation function
/// The return value is *ALWAYS* a two-elements array
pub fn evaluate(secret: Vec<Color>, user: Vec<Color>) -> (i32, i32) {
    do_evaluate(secret.clone(), user.as_slice())
}

pub fn do_evaluate(mut secret: Vec<Color>, user: &[Color]) -> (i32, i32) {
    let mut returned = (0, 0); // <1>
    if let Some((first_user, next_user)) = user.split_first() { // <2>
        if let Some(index) = secret.iter().position(|c| c == first_user) { // <3>
            if index == 0 {
                returned = (1, 0);
            } else {
                returned = (0, 1);
            }
            secret.remove(index); // <4>
        }
        if !next_user.is_empty() {
            let other = do_evaluate(secret, next_user); // <5>
            returned = (returned.0 + other.0, returned.1 + other.1); // <6>
        }
    }
    returned
}

fn main() {
    println!("Hello, world!");
}