def test_distance(self):
h8 = Position(Rank.EIGHT, File.H)
h7 = Position(Rank.SEVEN, File.H)
h1 = Position(Rank.ONE, File.H)
a8 = Position(Rank.EIGHT, File.A)
a1 = Position(Rank.ONE, File.A)
self.assertEqual(h8.dist(h7), 1)
self.assertEqual(h8.dist(h1), 7)
self.assertEqual(h8.dist(a8), 7)
self.assertEqual(a8.dist(h8), 7)
self.assertEqual(a1.dist(h8), 7)
def en_passant_handler(board, *, from_pos: Position, to_pos: Position):
board_move_func(board, from_pos=from_pos, to_pos=to_pos)
square = board[to_pos.rank][to_pos.file]
if to_pos == board.en_passant_pos: # capture(delete) the pawn
assert isinstance(square, Pawn)
board[from_pos.rank][to_pos.file] = None
board.en_passant_pos = None
if hasattr(square, 'figure_type') and square.figure_type is Type.PAWN and from_pos.dist(to_pos) == 2:
direction = square.color.forward_direction
board.en_passant_pos = Position(to_pos.rank - direction, to_pos.file)
def maybe_castle_wrapper(board, *, from_pos: Position, to_pos: Position):
board_move_func(board, from_pos=from_pos, to_pos=to_pos)
square = board[to_pos.rank][to_pos.file]
if getattr(square, 'figure_type', None) is Type.KING:
board.castling_perms[square.color] = CastlingPerm.NONE
if from_pos.dist(to_pos) == 2: # Castling -> Move rook
direction = from_pos.relative_direction_towards_position(to_pos)
old_file, new_file = ('a', 'd') if direction is Direction.LEFT else ('h', 'f')
rank = '1' if square.color is Color.WHITE else '8'
board.move(from_pos=P(f'{old_file}{rank}'), to_pos=P(f'{new_file}{rank}'))
def get_attackers(
self,
start_pos: Position,
color: Color
) -> Generator[Position, None, None]:
all_directions = list(Diagonal) + list(Direction)
positions_by_dir = self.get_positions_in_direction(start_pos, *all_directions)
positions_by_dir['Knight'] = filter(self.is_in_bounds, Knight.possible_positions(start_pos))
diagonals = [d.name for d in Diagonal] # TODO(yavor): cleanup from bug fix
directions = [d.name for d in Direction]
for direction, positions in positions_by_dir.items():
direction = getattr(direction, 'name', direction) # TODO(yavor): cleanup bug fix
for position in positions:
if not self.is_empty(position) and self.are_enemies(color, position):
enemy = self[position.rank][position.file]
enemy_type = enemy.figure_type
if direction == 'Knight' and enemy_type is Type.KNIGHT:
yield position
if direction in diagonals and enemy_type in [Type.BISHOP, Type.QUEEN]:
yield position
elif direction in directions and enemy_type in [Type.ROOK, Type.QUEEN]:
yield position
elif enemy_type is Type.KING and start_pos.dist(position) == 1:
yield position
elif enemy_type is Type.PAWN:
direction = Direction.DOWN if enemy.color == Color.WHITE else Direction.UP
pawn_positions = {
Position(rank=start_pos.rank + direction, file=start_pos.file + Direction.RIGHT),
Position(rank=start_pos.rank + direction, file=start_pos.file + Direction.LEFT)
}
if position in pawn_positions:
yield position
elif not self.is_empty(position) and direction != 'Knight':
# every other piece is blockable so we can stop going further
break
