Struct State 

pub struct State {
    pub pieces: [u64; 2],
    pub kings: u64,
}

The complete board state using bitboard representation.

This struct stores piece positions for both teams and king status using three 64-bit integers (24 bytes total).

Fields

• pieces[0]: Bitboard of all White pieces
• pieces[1]: Bitboard of all Black pieces
• kings: Bitboard of all king pieces (subset of pieces[0] | pieces[1])

Invariants

• pieces[0] & pieces[1] == 0 (no square has both colors)
• kings & (pieces[0] | pieces[1]) == kings (kings must be on a piece)
• Each team has at most 16 pieces

Fields

pieces: [u64; 2]

Bitboard of pieces for each team: pieces[0] = White, pieces[1] = Black.

kings: u64

Bitboard of king pieces (men that have been promoted).

Implementations

impl State

pub const fn new(pieces: [u64; 2], kings: u64) -> Self

Creates a new state.

pub const fn default() -> Self

Creates a new state with default configuration.

pub const fn zeros() -> Self

Creates a new state with zeros.

impl State

pub fn validate(&self)

Validates the state invariants in debug builds.

This method uses debug_assert! for performance, so checks are only performed in debug builds. In release builds, this is a no-op.

Panics (debug builds only)

Panics if any invariant is violated:

• A square is occupied by both teams
• A king exists on an empty square
• A team has more than 16 pieces

Note

This does NOT validate that pieces on the promotion row are kings. During multi-capture sequences, pawns can temporarily be on the promotion row before being promoted at the end of the sequence. The promotion logic in generate_pawn_captures_at ensures pawns are promoted when sequences end on the promotion row.

pub const fn empty(&self) -> u64

The bitboard representing the empty squares.

pub const fn apply_(&mut self, other: &Self)

Applies a transformation to the state in-place.

pub fn apply(&self, other: &Self) -> Self

Returns a new state after applying the transformation.

pub const fn rotate_(&mut self)

Rotates the state by 180 degrees in-place.

pub fn rotate(&self) -> Self

Returns a new state after rotating by 180 degrees.

Trait Implementations

impl Clone for State

fn clone(&self) -> State

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for State

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

Formats the value using the given formatter.

impl Default for State

fn default() -> Self

Returns the initial game position.

This is equivalent to State::default().

impl Display for State

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

Formats the value using the given formatter.

impl Hash for State

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 Ord for State

fn cmp(&self, other: &State) -> 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,

Restrict a value to a certain interval.

impl PartialEq for State

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

Tests for self and other values to be equal, and is used by ==.

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

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

impl PartialOrd for State

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

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

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

Tests less than (for self and other) and is used by the < operator.

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

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

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

Tests greater than (for self and other) and is used by the > operator.

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

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

impl Copy for State

impl Eq for State

impl StructuralPartialEq for State