Struct cozy_chess_types::bitboard::BitBoard

pub struct BitBoard(pub u64);

A bitboard. A bitboard is an ordered set of squares.

Operators are overloaded to work as set operations accordingly:

let a1 = Square::A1.bitboard();
let b1 = Square::B1.bitboard();
let c1 = Square::C1.bitboard();
let x = a1 | b1;
let y = a1 | c1;
// Union
assert_eq!(x | y, a1 | b1 | c1);
// Intersection
assert_eq!(x & y, a1);
// Symmetric difference
assert_eq!(x ^ y, b1 | c1);
// Difference
assert_eq!(x - y, b1);
// Complement
assert_eq!(!x, BitBoard::FULL - x);

Tuple Fields

0: u64

The backing u64. A square is present in the set if the bit at 1 << square as u8 is set.

Implementations

impl BitBoard

pub const EMPTY: Self = _

An empty bitboard.

Examples

assert_eq!(BitBoard::EMPTY, bitboard! {
    . . . . . . . .
    . . . . . . . .
    . . . . . . . .
    . . . . . . . .
    . . . . . . . .
    . . . . . . . .
    . . . . . . . .
    . . . . . . . .
});

pub const FULL: Self = _

A bitboard with every square.

Examples

assert_eq!(BitBoard::FULL, bitboard! {
    X X X X X X X X
    X X X X X X X X
    X X X X X X X X
    X X X X X X X X
    X X X X X X X X
    X X X X X X X X
    X X X X X X X X
    X X X X X X X X
});

pub const EDGES: Self = Self::__EDGES

The edges on the board.

Examples

assert_eq!(BitBoard::EDGES, bitboard! {
    X X X X X X X X
    X . . . . . . X
    X . . . . . . X
    X . . . . . . X
    X . . . . . . X
    X . . . . . . X
    X . . . . . . X
    X X X X X X X X
});

pub const CORNERS: Self = Self::__CORNERS

The corners of the board.

Examples

assert_eq!(BitBoard::CORNERS, bitboard! {
    X . . . . . . X
    . . . . . . . .
    . . . . . . . .
    . . . . . . . .
    . . . . . . . .
    . . . . . . . .
    . . . . . . . .
    X . . . . . . X
});

pub const DARK_SQUARES: Self = Self::__DARK_SQUARES

The dark squares on the board.

Examples

assert_eq!(BitBoard::DARK_SQUARES, bitboard! {
    . X . X . X . X
    X . X . X . X .
    . X . X . X . X
    X . X . X . X .
    . X . X . X . X
    X . X . X . X .
    . X . X . X . X
    X . X . X . X .
});

pub const LIGHT_SQUARES: Self = Self::__LIGHT_SQUARES

The light squares on the board.

Examples

assert_eq!(BitBoard::LIGHT_SQUARES, bitboard! {
    X . X . X . X .
    . X . X . X . X
    X . X . X . X .
    . X . X . X . X
    X . X . X . X .
    . X . X . X . X
    X . X . X . X .
    . X . X . X . X
});

pub const fn flip_ranks(self) -> Self

Flip the bitboard’s ranks.

Examples

let bb = bitboard! {
    . . . . . . . .
    . . . . . . . .
    . . X X X . . .
    . . X . X X . .
    . . X X X X . .
    . . X . X . . .
    . . . . . . . .
    . . . . . . . .
};
assert_eq!(bb.flip_ranks(), bitboard! {
    . . . . . . . .
    . . . . . . . .
    . . X . X . . .
    . . X X X X . .
    . . X . X X . .
    . . X X X . . .
    . . . . . . . .
    . . . . . . . .
});

pub const fn flip_files(self) -> Self

Flip the bitboard’s files.

Examples

let bb = bitboard! {
    . . . . . . . .
    . . . . . . . .
    . . X X X . . .
    . . X . X X . .
    . . X X X X . .
    . . X . X . . .
    . . . . . . . .
    . . . . . . . .
};
assert_eq!(bb.flip_files(), bitboard! {
    . . . . . . . .
    . . . . . . . .
    . . . X X X . .
    . . X X . X . .
    . . X X X X . .
    . . . X . X . .
    . . . . . . . .
    . . . . . . . .
});

pub const fn len(self) -> u32

Count the number of squares in the bitboard.

Examples

assert_eq!(BitBoard::EMPTY.len(), 0);
let bb = bitboard! {
    . . . . . . . .
    . . . . . . . .
    . . X X X . . .
    . . X . X X . .
    . . X X X X . .
    . . X . X . . .
    . . . . . . . .
    . . . . . . . .
};
assert_eq!(bb.len(), 12);

pub const fn has(self, square: Square) -> bool

Check if a Square is set.

Examples

let bb = bitboard! {
    . . . . . . . .
    . . . . . . . .
    . . X X X . . .
    . . X . X X . .
    . . X X X X . .
    . . X . X . . .
    . . . . . . . .
    . . . . . . . .
};
assert!(bb.has(Square::C3));
assert!(!bb.has(Square::B2));

pub const fn is_disjoint(self, other: BitBoard) -> bool

Check if a bitboard contains no squares in common with another.

Examples

let bb_a = bitboard! {
    X X X . . . . .
    X . X X . . . .
    X X X X . . . .
    X . X . . . . .
    . . . . . . . .
    . . . . . . . .
    . . . . . . . .
    . . . . . . . .
};
let bb_b = bitboard! {
    . . . . . . . .
    . . . . . . . .
    . . . . . . . .
    . . . . . . . .
    . . . . X X X .
    . . . . X . X X
    . . . . X X X X
    . . . . X . X .
};
assert!(bb_a.is_disjoint(bb_b));

pub const fn is_subset(self, other: BitBoard) -> bool

Check if a bitboard is a subset of another.

Examples

let bb = bitboard! {
    . . . . . . . .
    . X X X X X . .
    . X X X X X X .
    . X X . X X X .
    . X X X X X X .
    . X X X X X . .
    . X X . X X . .
    . . . . . . . .
};
let subset = bitboard! {
    . . . . . . . .
    . . . . . . . .
    . . X X X . . .
    . . X . X X . .
    . . X X X X . .
    . . X . X . . .
    . . . . . . . .
    . . . . . . . .
};
assert!(subset.is_subset(bb));

pub const fn is_superset(self, other: BitBoard) -> bool

Check if a bitboard is a superset of another.

Examples

let bb = bitboard! {
    . . . . . . . .
    . . . . . . . .
    . . X X X . . .
    . . X . X X . .
    . . X X X X . .
    . . X . X . . .
    . . . . . . . .
    . . . . . . . .
};
let superset = bitboard! {
    . . . . . . . .
    . X X X X X . .
    . X X X X X X .
    . X X . X X X .
    . X X X X X X .
    . X X X X X . .
    . X X . X X . .
    . . . . . . . .
};
assert!(superset.is_superset(bb));

pub const fn is_empty(self) -> bool

Checks if the BitBoard is empty.

Examples

assert!(BitBoard::EMPTY.is_empty());
let bb = bitboard! {
    . . . . . . . .
    . . . . . . . .
    . . X X X . . .
    . . X . X X . .
    . . X X X X . .
    . . X . X . . .
    . . . . . . . .
    . . . . . . . .
};
assert!(!bb.is_empty());

pub const fn next_square(self) -> Option<Square>

Grabs the first square if the bitboard is not empty.

Examples

assert!(BitBoard::EMPTY.next_square().is_none());
let bb = bitboard! {
    . . . . . . . .
    . . . . . . . .
    . . X X X . . .
    . . X . X X . .
    . . X X X X . .
    . . X . X . . .
    . . . . . . . .
    . . . . . . . .
};
assert_eq!(bb.next_square(), Some(Square::C3));

pub fn iter(self) -> BitBoardIter

Iterate the squares in the bitboard, ordered by square.

Examples

let bb = BitBoard::FULL;
let squares = &Square::ALL;
for (s1, &s2) in bb.iter().zip(squares) {
    assert_eq!(s1, s2);
}

pub fn iter_subsets(self) -> BitBoardSubsetIter

Iterate all subsets of a bitboard. Subsets are produced in lexicographic order; Each subset is greater than the last.

let bb = bitboard! {
    . . . . . . . .
    . . . . . . . .
    . . X X X . . .
    . . X . X X . .
    . . X X X X . .
    . . X . X . . .
    . . . . . . . .
    . . . . . . . .
};
for subset in bb.iter_subsets() {
    assert!(subset.is_subset(bb));
}

Trait Implementations

impl BitAnd for BitBoard

type Output = BitBoard

The resulting type after applying the & operator.

fn bitand(self, rhs: Self) -> Self::Output

Performs the & operation.

impl BitAndAssign for BitBoard

fn bitand_assign(&mut self, rhs: Self)

Performs the &= operation.

impl BitOr for BitBoard

type Output = BitBoard

The resulting type after applying the | operator.

fn bitor(self, rhs: Self) -> Self::Output

Performs the | operation.

impl BitOrAssign for BitBoard

fn bitor_assign(&mut self, rhs: Self)

Performs the |= operation.

impl BitXor for BitBoard

type Output = BitBoard

The resulting type after applying the ^ operator.

fn bitxor(self, rhs: Self) -> Self::Output

Performs the ^ operation.

impl BitXorAssign for BitBoard

fn bitxor_assign(&mut self, rhs: Self)

Performs the ^= operation.

impl Clone for BitBoard

fn clone(&self) -> BitBoard

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for BitBoard

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for BitBoard

fn default() -> BitBoard

Returns the “default value” for a type.

impl From<File> for BitBoard

fn from(value: File) -> Self

Converts to this type from the input type.

impl From<Rank> for BitBoard

fn from(value: Rank) -> Self

Converts to this type from the input type.

impl From<Square> for BitBoard

fn from(value: Square) -> Self

Converts to this type from the input type.

impl FromIterator<Square> for BitBoard

fn from_iter<T: IntoIterator<Item = Square>>(iter: T) -> Self

Creates a value from an iterator.

impl Hash for BitBoard

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl IntoIterator for BitBoard

type Item = Square

The type of the elements being iterated over.

type IntoIter = BitBoardIter

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl Not for BitBoard

type Output = BitBoard

The resulting type after applying the ! operator.

fn not(self) -> Self::Output

Performs the unary ! operation.

impl Ord for BitBoard

fn cmp(&self, other: &BitBoard) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized + PartialOrd,

Restrict a value to a certain interval.

impl PartialEq for BitBoard

fn eq(&self, other: &BitBoard) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for BitBoard

fn partial_cmp(&self, other: &BitBoard) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl Sub for BitBoard

type Output = BitBoard

The resulting type after applying the - operator.

fn sub(self, rhs: Self) -> Self::Output

Performs the - operation.

impl SubAssign for BitBoard

fn sub_assign(&mut self, rhs: Self)

Performs the -= operation.

impl Copy for BitBoard

impl Eq for BitBoard

impl StructuralPartialEq for BitBoard