chessfriend/board/src/bitboard.rs

// Eryn Wells <eryn@erynwells.me>

use crate::square::Square;

#[derive(Clone, Copy, Debug, Default, Eq, Hash, Ord, PartialEq, PartialOrd)]
pub struct BitBoard(pub u64);

impl BitBoard {
    fn is_empty(&self) -> bool {
        self.0 == 0
    }

    fn has_piece_at(&self, sq: &Square) -> bool {
        (self.0 & (1 << sq.index)) > 0
    }

    fn place_piece_at(&mut self, sq: &Square) {
        self.0 |= 1 << sq.index
    }
}

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

    #[test]
    fn is_empty() {
        assert!(BitBoard(0).is_empty());
    }

    #[test]
    fn has_piece_at() {
        let bb = BitBoard(0b1001100);

        assert!(bb.has_piece_at(
            &Square::from_algebraic_string("a3").expect("Unable to get square for 'a3'")
        ));
        assert!(!bb.has_piece_at(
            &Square::from_algebraic_string("a2").expect("Unable to get square for 'a2'")
        ));
    }

    #[test]
    fn place_piece_at() {
        let mut bb = BitBoard(0b1001100);
        bb.place_piece_at(&Square::from_index(34).expect("Invalid square index"));
        assert!(bb.has_piece_at(&Square::from_index(34).expect("Invalid square index")));
    }
}