Add 'Rank::{up,down}'

This commit is contained in:
Bruno BELANYI 2022-07-16 14:34:46 +02:00
parent 2b4797ec47
commit 7a7e7f3665

View file

@ -54,6 +54,18 @@ impl Rank {
self as usize self as usize
} }
/// Return the [Rank] one-row up, as seen from white's perspective. Wraps around the board.
pub fn up(self) -> Self {
// SAFETY: we know the value is in-bounds, through masking
unsafe { Self::from_index_unchecked(self.index().wrapping_add(1) & 7) }
}
/// Return the [Rank] one-row down, as seen from white's perspective. Wraps around the board.
pub fn down(self) -> Self {
// SAFETY: we know the value is in-bounds, through masking
unsafe { Self::from_index_unchecked(self.index().wrapping_sub(1) & 7) }
}
/// Turn a [Rank] into a [Bitboard] of all squares in that rank. /// Turn a [Rank] into a [Bitboard] of all squares in that rank.
#[inline(always)] #[inline(always)]
pub fn into_bitboard(self) -> Bitboard { pub fn into_bitboard(self) -> Bitboard {
@ -80,6 +92,20 @@ mod test {
assert_eq!(Rank::Eighth.index(), 7); assert_eq!(Rank::Eighth.index(), 7);
} }
#[test]
fn up() {
assert_eq!(Rank::First.up(), Rank::Second);
assert_eq!(Rank::Second.up(), Rank::Third);
assert_eq!(Rank::Eighth.up(), Rank::First);
}
#[test]
fn down() {
assert_eq!(Rank::First.down(), Rank::Eighth);
assert_eq!(Rank::Second.down(), Rank::First);
assert_eq!(Rank::Eighth.down(), Rank::Seventh);
}
#[test] #[test]
fn into_bitboard() { fn into_bitboard() {
assert_eq!(Rank::First.into_bitboard(), Bitboard::RANKS[0]); assert_eq!(Rank::First.into_bitboard(), Bitboard::RANKS[0]);