def make_safe_move(self, move: Union[Move, str]):
"""
Same as Board.make_move, but validates if the move is legal first (slower).
"""
if isinstance(move, str):
move = Move.from_uci(move)
if move in self.legal_moves:
self.make_move(move)
else:
raise IllegalMove(f"Move {move} is illegal.")
def make_move(self, move: Union[Move, str]):
"""
Moves a piece on the game. Warning: moves are not checked for legality in this function, this is for speed.
The consumer of this API should enforce legality by checking Bitboard.legal_moves.
"""
if isinstance(move, str):
move = Move.from_uci(move)
self._save()
piece = self.piece_at(move.from_square)
captured_piece = self.piece_at(move.to_square)
if not piece:
raise IllegalMove(f"No piece at {move.from_square}")
if piece.colour != self.turn:
raise IllegalMove(f"Can't move that piece, it's not your turn.")
backrank = 7 if self.turn == WHITE else 0
# Castling if a king is moving more than 1 square
if piece.type == KING and abs(move.from_square.file -
move.to_square.file) > 1:
# Move King
self.remove_piece(move.from_square)
self.place_piece(move.to_square, piece.type, piece.colour)
# Move Rook
rook_shift = 1 if move.to_square.file < move.from_square.file else -1 # For Queen/Kingside
if rook_shift > 0: # Queenside
self.remove_piece(Square.from_file_rank(
0, move.to_square.rank))
else:
self.remove_piece(Square.from_file_rank(
7, move.to_square.rank))
self.place_piece(
Square.from_file_rank(move.to_square.file + rook_shift,
move.from_square.rank),
ROOK,
piece.colour,
)
self.repetitions = [] # Reset repetitions when castling
elif piece.type == PAWN and move.to_square == self.en_passant_sq: # Take piece by en_passant
shift = -8 if piece.colour == WHITE else 8
capture_sq = self.en_passant_sq + shift
captured_piece = self.remove_piece(capture_sq)
self.remove_piece(move.from_square)
self.place_piece(move.to_square, piece.type, piece.colour)
elif piece.type == PAWN and move.to_square.rank == backrank: # Promotion
self.remove_piece(move.from_square)
self.place_piece(move.to_square, move.promotion,
piece.colour) # Assume queen for now
else:
# Regular piece move
self.remove_piece(move.from_square)
self.place_piece(move.to_square, piece.type, piece.colour)
# Set En Passant square
if piece.type == PAWN:
distance = move.to_square.rank - move.from_square.rank
if abs(distance) == 2:
if distance > 0: # White pawn goes from low rank to higher
self.en_passant_sq = Square(
move.from_square +
8) # En Passant square is 1 rank behind
else: # Black pawn
self.en_passant_sq = Square(move.from_square - 8)
else:
self.en_passant_sq = None
else:
self.en_passant_sq = None
# Update castling rights if the king or rook move
if piece.type in (KING, ROOK):
self._update_castling_rights()
# Reset halfmove clock if a pawn moved or a piece was captured
if piece.type == PAWN or captured_piece:
self.halfmove_clock = 0
self.repetitions = []
else:
self.halfmove_clock += 1
if self.track_repetitions:
self.repetitions.append(
self._short_fen) # Imperfect repetition tracking
if self.turn == BLACK: # Increment full moves after Black's turn
self.fullmoves += 1
self.move_history.append(move)
self.turn = not self.turn