GameState

Removes all en-passant targets created by the specified color.

White's double pawn pushes create targets on rank 3. Black's double pawn pushes create targets on rank 6.

Consumes the dice required for move from this state's dice pool.

Resolves the mover piece type from the mailbox and delegates to GameFlags.consumeDiceFor. Returns GameFlags.Invalid if the required dice are not available in this state's pool.

Explicitly ends the current player's turn.

Toggles the active color to the opponent, increments the full-move number if the current player is Black, and clears any stale en-passant targets left by the player whose turn is starting. Must be called manually by the orchestrator after applying a sequence of micro-moves.

Value equality over every field, mailbox included — hand-written rather than derived because mailbox is an IArray, whose default equality is by reference; java.util.Arrays.equals compares it by content instead.

Worth stating explicitly because the opposite was once assumed in ExpectimaxSearch (#514): two positions reached by different move orders do compare equal, so GameState is usable as a Map/Set key directly. A separate key type is only ever warranted on cost grounds — hashCode walks the 64-entry mailbox — never on correctness.

Calculates a hash code value for the object.

The default hashing algorithm is platform dependent.

Note that it is allowed for two objects to have identical hash codes (o1.hashCode.equals(o2.hashCode)) yet not be equal (o1.equals(o2) returns false). A degenerate implementation could always return 0. However, it is required that if two objects are equal (o1.equals(o2) returns true) that they have identical hash codes (o1.hashCode.equals(o2.hashCode)). Therefore, when overriding this method, be sure to verify that the behavior is consistent with the equals method.

Returns true when move captures the opponent's King from this state (win condition).

Applies a MicroMove (turn-based) to the current game state.

Handles piece movement, captures, and basic bitboard updates. This is a raw micro-move application. According to Dice Chess micro-move semantics, this method does not flip the active color or increment the full-move number. Turn transitions must be explicitly managed via GameState.endTurn().

Dice pool: The die matching the moving piece type is automatically removed from state.dicePool. If the pool is empty (e.g. when replaying from perft or search without dice context), the pool is left unchanged.

The half-move clock is reset to 0 on pawn moves and captures; otherwise it is increased by 1.

Returns a copy of this state with the active color set to c.

Used during move generation to explicitly override the active color.

Returns a copy of this state with the dice pool replaced by pool.

Used to track remaining dice during multi-micro-move turn enumeration.

Overwrites only the dice-pool slots of this state's flags with those from src, leaving all other flag bits (castling, EP, active color, HMC) untouched. Allocation-free alternative to withDicePool for hot paths.

Returns the precalculated Zobrist key, or computes it on demand if unpopulated (0L).

⚠️ Incremental-hash contract: position-relevant fields (boards, mailbox, flags, enPassant) must NEVER be mutated via a raw copy(...) — that silently carries this cached key forward and every later consumer of the hash reads a stale value. Mutate through the hash-aware paths (makeMove, endTurn, withDicePool, withDiceSlotsOf, withActiveColor, clearEnPassant) or reset zobristKey = 0L in the copy. Known deliberate exception: dicechess.engine.search.KingCaptureProbability mutates dice slots via raw copy inside its self-contained DFS, which never consults the hash.

The 0L sentinel means a position whose true key is genuinely zero recomputes on every call — a ~2^-64 harmless performance quirk, accepted to keep the field allocation-free.

An iterator over the names of all the elements of this product.

An iterator over all the elements of this product.