Expand core constant definitions

More verbose, but better IDE support

Author: niklasf

chess/__init__.py

@@ -32,12 +32,20 @@
 
 
 Color: TypeAlias = bool
-COLORS = [WHITE, BLACK] = [True, False]
+WHITE: Color = True
+BLACK: Color = False
+COLORS: List[Color] = [WHITE, BLACK]
 ColorName = Literal["white", "black"]
 COLOR_NAMES: List[ColorName] = ["black", "white"]
 
 PieceType: TypeAlias = int
-PIECE_TYPES = [PAWN, KNIGHT, BISHOP, ROOK, QUEEN, KING] = range(1, 7)
+PAWN: PieceType = 1
+KNIGHT: PieceType = 2
+BISHOP: PieceType = 3
+ROOK: PieceType = 4
+QUEEN: PieceType = 5
+KING: PieceType = 6
+PIECE_TYPES: List[PieceType] = [PAWN, KNIGHT, BISHOP, ROOK, QUEEN, KING]
 PIECE_SYMBOLS = [None, "p", "n", "b", "r", "q", "k"]
 PIECE_NAMES = [None, "pawn", "knight", "bishop", "rook", "queen", "king"]
 
@@ -162,16 +170,71 @@ class AmbiguousMoveError(ValueError):
 
 
 Square: TypeAlias = int
-SQUARES = [
-    A1, B1, C1, D1, E1, F1, G1, H1,
-    A2, B2, C2, D2, E2, F2, G2, H2,
-    A3, B3, C3, D3, E3, F3, G3, H3,
-    A4, B4, C4, D4, E4, F4, G4, H4,
-    A5, B5, C5, D5, E5, F5, G5, H5,
-    A6, B6, C6, D6, E6, F6, G6, H6,
-    A7, B7, C7, D7, E7, F7, G7, H7,
-    A8, B8, C8, D8, E8, F8, G8, H8,
-] = range(64)
+A1: Square = 0
+B1: Square = 1
+C1: Square = 2
+D1: Square = 3
+E1: Square = 4
+F1: Square = 5
+G1: Square = 6
+H1: Square = 7
+A2: Square = 8
+B2: Square = 9
+C2: Square = 10
+D2: Square = 11
+E2: Square = 12
+F2: Square = 13
+G2: Square = 14
+H2: Square = 15
+A3: Square = 16
+B3: Square = 17
+C3: Square = 18
+D3: Square = 19
+E3: Square = 20
+F3: Square = 21
+G3: Square = 22
+H3: Square = 23
+A4: Square = 24
+B4: Square = 25
+C4: Square = 26
+D4: Square = 27
+E4: Square = 28
+F4: Square = 29
+G4: Square = 30
+H4: Square = 31
+A5: Square = 32
+B5: Square = 33
+C5: Square = 34
+D5: Square = 35
+E5: Square = 36
+F5: Square = 37
+G5: Square = 38
+H5: Square = 39
+A6: Square = 40
+B6: Square = 41
+C6: Square = 42
+D6: Square = 43
+E6: Square = 44
+F6: Square = 45
+G6: Square = 46
+H6: Square = 47
+A7: Square = 48
+B7: Square = 49
+C7: Square = 50
+D7: Square = 51
+E7: Square = 52
+F7: Square = 53
+G7: Square = 54
+H7: Square = 55
+A8: Square = 56
+B8: Square = 57
+C8: Square = 58
+D8: Square = 59
+E8: Square = 60
+F8: Square = 61
+G8: Square = 62
+H8: Square = 63
+SQUARES: List[Square] = list(range(64))
 
 SQUARE_NAMES = [f + r for r in RANK_NAMES for f in FILE_NAMES]
 
@@ -234,53 +297,106 @@ def square_mirror(square: Square) -> Square:
     """Mirrors the square vertically."""
     return square ^ 0x38
 
-SQUARES_180 = [square_mirror(sq) for sq in SQUARES]
+SQUARES_180: List[Square] = [square_mirror(sq) for sq in SQUARES]
 
 
 Bitboard: TypeAlias = int
-BB_EMPTY = 0
-BB_ALL = 0xffff_ffff_ffff_ffff
-
-BB_SQUARES = [
-    BB_A1, BB_B1, BB_C1, BB_D1, BB_E1, BB_F1, BB_G1, BB_H1,
-    BB_A2, BB_B2, BB_C2, BB_D2, BB_E2, BB_F2, BB_G2, BB_H2,
-    BB_A3, BB_B3, BB_C3, BB_D3, BB_E3, BB_F3, BB_G3, BB_H3,
-    BB_A4, BB_B4, BB_C4, BB_D4, BB_E4, BB_F4, BB_G4, BB_H4,
-    BB_A5, BB_B5, BB_C5, BB_D5, BB_E5, BB_F5, BB_G5, BB_H5,
-    BB_A6, BB_B6, BB_C6, BB_D6, BB_E6, BB_F6, BB_G6, BB_H6,
-    BB_A7, BB_B7, BB_C7, BB_D7, BB_E7, BB_F7, BB_G7, BB_H7,
-    BB_A8, BB_B8, BB_C8, BB_D8, BB_E8, BB_F8, BB_G8, BB_H8,
-] = [1 << sq for sq in SQUARES]
-
-BB_CORNERS = BB_A1 | BB_H1 | BB_A8 | BB_H8
-BB_CENTER = BB_D4 | BB_E4 | BB_D5 | BB_E5
-
-BB_LIGHT_SQUARES = 0x55aa_55aa_55aa_55aa
-BB_DARK_SQUARES = 0xaa55_aa55_aa55_aa55
-
-BB_FILES = [
-    BB_FILE_A,
-    BB_FILE_B,
-    BB_FILE_C,
-    BB_FILE_D,
-    BB_FILE_E,
-    BB_FILE_F,
-    BB_FILE_G,
-    BB_FILE_H,
-] = [0x0101_0101_0101_0101 << i for i in range(8)]
-
-BB_RANKS = [
-    BB_RANK_1,
-    BB_RANK_2,
-    BB_RANK_3,
-    BB_RANK_4,
-    BB_RANK_5,
-    BB_RANK_6,
-    BB_RANK_7,
-    BB_RANK_8,
-] = [0xff << (8 * i) for i in range(8)]
-
-BB_BACKRANKS = BB_RANK_1 | BB_RANK_8
+BB_EMPTY: Bitboard = 0
+BB_ALL: Bitboard = 0xffff_ffff_ffff_ffff
+
+BB_A1: Bitboard = 1 << A1
+BB_B1: Bitboard = 1 << B1
+BB_C1: Bitboard = 1 << C1
+BB_D1: Bitboard = 1 << D1
+BB_E1: Bitboard = 1 << E1
+BB_F1: Bitboard = 1 << F1
+BB_G1: Bitboard = 1 << G1
+BB_H1: Bitboard = 1 << H1
+BB_A2: Bitboard = 1 << A2
+BB_B2: Bitboard = 1 << B2
+BB_C2: Bitboard = 1 << C2
+BB_D2: Bitboard = 1 << D2
+BB_E2: Bitboard = 1 << E2
+BB_F2: Bitboard = 1 << F2
+BB_G2: Bitboard = 1 << G2
+BB_H2: Bitboard = 1 << H2
+BB_A3: Bitboard = 1 << A3
+BB_B3: Bitboard = 1 << B3
+BB_C3: Bitboard = 1 << C3
+BB_D3: Bitboard = 1 << D3
+BB_E3: Bitboard = 1 << E3
+BB_F3: Bitboard = 1 << F3
+BB_G3: Bitboard = 1 << G3
+BB_H3: Bitboard = 1 << H3
+BB_A4: Bitboard = 1 << A4
+BB_B4: Bitboard = 1 << B4
+BB_C4: Bitboard = 1 << C4
+BB_D4: Bitboard = 1 << D4
+BB_E4: Bitboard = 1 << E4
+BB_F4: Bitboard = 1 << F4
+BB_G4: Bitboard = 1 << G4
+BB_H4: Bitboard = 1 << H4
+BB_A5: Bitboard = 1 << A5
+BB_B5: Bitboard = 1 << B5
+BB_C5: Bitboard = 1 << C5
+BB_D5: Bitboard = 1 << D5
+BB_E5: Bitboard = 1 << E5
+BB_F5: Bitboard = 1 << F5
+BB_G5: Bitboard = 1 << G5
+BB_H5: Bitboard = 1 << H5
+BB_A6: Bitboard = 1 << A6
+BB_B6: Bitboard = 1 << B6
+BB_C6: Bitboard = 1 << C6
+BB_D6: Bitboard = 1 << D6
+BB_E6: Bitboard = 1 << E6
+BB_F6: Bitboard = 1 << F6
+BB_G6: Bitboard = 1 << G6
+BB_H6: Bitboard = 1 << H6
+BB_A7: Bitboard = 1 << A7
+BB_B7: Bitboard = 1 << B7
+BB_C7: Bitboard = 1 << C7
+BB_D7: Bitboard = 1 << D7
+BB_E7: Bitboard = 1 << E7
+BB_F7: Bitboard = 1 << F7
+BB_G7: Bitboard = 1 << G7
+BB_H7: Bitboard = 1 << H7
+BB_A8: Bitboard = 1 << A8
+BB_B8: Bitboard = 1 << B8
+BB_C8: Bitboard = 1 << C8
+BB_D8: Bitboard = 1 << D8
+BB_E8: Bitboard = 1 << E8
+BB_F8: Bitboard = 1 << F8
+BB_G8: Bitboard = 1 << G8
+BB_H8: Bitboard = 1 << H8
+BB_SQUARES: List[Bitboard] = [1 << sq for sq in SQUARES]
+
+BB_CORNERS: Bitboard = BB_A1 | BB_H1 | BB_A8 | BB_H8
+BB_CENTER: Bitboard = BB_D4 | BB_E4 | BB_D5 | BB_E5
+
+BB_LIGHT_SQUARES: Bitboard = 0x55aa_55aa_55aa_55aa
+BB_DARK_SQUARES: Bitboard = 0xaa55_aa55_aa55_aa55
+
+BB_FILE_A: Bitboard = 0x0101_0101_0101_0101 << 0
+BB_FILE_B: Bitboard = 0x0101_0101_0101_0101 << 1
+BB_FILE_C: Bitboard = 0x0101_0101_0101_0101 << 2
+BB_FILE_D: Bitboard = 0x0101_0101_0101_0101 << 3
+BB_FILE_E: Bitboard = 0x0101_0101_0101_0101 << 4
+BB_FILE_F: Bitboard = 0x0101_0101_0101_0101 << 5
+BB_FILE_G: Bitboard = 0x0101_0101_0101_0101 << 6
+BB_FILE_H: Bitboard = 0x0101_0101_0101_0101 << 7
+BB_FILES: List[Bitboard] = [BB_FILE_A, BB_FILE_B, BB_FILE_C, BB_FILE_D, BB_FILE_E, BB_FILE_F, BB_FILE_G, BB_FILE_H]
+
+BB_RANK_1: Bitboard = 0xff << (8 * 0)
+BB_RANK_2: Bitboard = 0xff << (8 * 1)
+BB_RANK_3: Bitboard = 0xff << (8 * 2)
+BB_RANK_4: Bitboard = 0xff << (8 * 3)
+BB_RANK_5: Bitboard = 0xff << (8 * 4)
+BB_RANK_6: Bitboard = 0xff << (8 * 5)
+BB_RANK_7: Bitboard = 0xff << (8 * 6)
+BB_RANK_8: Bitboard = 0xff << (8 * 7)
+BB_RANKS: List[Bitboard] = [BB_RANK_1, BB_RANK_2, BB_RANK_3, BB_RANK_4, BB_RANK_5, BB_RANK_6, BB_RANK_7, BB_RANK_8]
+
+BB_BACKRANKS: Bitboard = BB_RANK_1 | BB_RANK_8
 
 
 def lsb(bb: Bitboard) -> int:
@@ -397,9 +513,9 @@ def _sliding_attacks(square: Square, occupied: Bitboard, deltas: Iterable[int])
 def _step_attacks(square: Square, deltas: Iterable[int]) -> Bitboard:
     return _sliding_attacks(square, BB_ALL, deltas)
 
-BB_KNIGHT_ATTACKS = [_step_attacks(sq, [17, 15, 10, 6, -17, -15, -10, -6]) for sq in SQUARES]
-BB_KING_ATTACKS = [_step_attacks(sq, [9, 8, 7, 1, -9, -8, -7, -1]) for sq in SQUARES]
-BB_PAWN_ATTACKS = [[_step_attacks(sq, deltas) for sq in SQUARES] for deltas in [[-7, -9], [7, 9]]]
+BB_KNIGHT_ATTACKS: List[Bitboard] = [_step_attacks(sq, [17, 15, 10, 6, -17, -15, -10, -6]) for sq in SQUARES]
+BB_KING_ATTACKS: List[Bitboard] = [_step_attacks(sq, [9, 8, 7, 1, -9, -8, -7, -1]) for sq in SQUARES]
+BB_PAWN_ATTACKS: List[List[Bitboard]] = [[_step_attacks(sq, deltas) for sq in SQUARES] for deltas in [[-7, -9], [7, 9]]]
 
 
 def _edges(square: Square) -> Bitboard: