89 lines
2.5 KiB
Nim
89 lines
2.5 KiB
Nim
## Handling of moves
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import pieces
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type
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MoveFlag* = enum
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## An enumeration of move flags
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Default = 0'u16, # No flag
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EnPassant = 1, # Move is a capture with en passant
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Capture = 2, # Move is a capture
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DoublePush = 4, # Move is a double pawn push
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# Castling metadata
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CastleLong = 8,
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CastleShort = 16,
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# Pawn promotion metadata
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PromoteToQueen = 32,
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PromoteToRook = 64,
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PromoteToBishop = 128,
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PromoteToKnight = 256
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Move* = object
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## A chess move
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startSquare*: Square
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targetSquare*: Square
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flags*: uint16
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MoveList* = object
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## A list of moves
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data: array[218, Move]
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len: int8
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func `[]`*(self: MoveList, i: SomeInteger): Move =
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when not defined(danger):
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if i >= self.len:
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raise newException(IndexDefect, &"move list access out of bounds ({i} >= {self.len})")
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result = self.data[i]
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iterator items*(self: MoveList): Move =
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var i = 0
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while self.len > i:
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yield self.data[i]
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inc(i)
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iterator pairs*(self: MoveList): tuple[i: int, move: Move] =
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var i = 0
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for item in self:
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yield (i, item)
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func add*(self: var MoveList, move: Move) {.inline.} =
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self.data[self.len] = move
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inc(self.len)
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func clear*(self: var MoveList) {.inline.} =
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self.len = 0
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func contains*(self: MoveList, move: Move): bool {.inline.} =
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for item in self:
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if move == item:
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return true
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return false
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func len*(self: MoveList): int {.inline.} = self.len
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# A bunch of move creation utilities
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func createMove*(startSquare, targetSquare: Square, flags: varargs[MoveFlag]): Move =
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result = Move(startSquare: startSquare, targetSquare: targetSquare, flags: Default.uint16)
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for flag in flags:
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result.flags = result.flags or flag.uint16
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proc createMove*(startSquare, targetSquare: string, flags: varargs[MoveFlag]): Move =
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result = createMove(startSquare.toSquare(), targetSquare.toSquare(), flags)
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func createMove*(startSquare, targetSquare: SomeInteger, flags: varargs[MoveFlag]): Move =
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result = createMove(Square(startSquare.int8), Square(targetSquare.int8), flags)
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func createMove*(startSquare: Square, targetSquare: SomeInteger, flags: varargs[MoveFlag]): Move =
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result = createMove(startSquare, Square(targetSquare.int8), flags)
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func nullMove*: Move {.inline.} = createMove(nullSquare(), nullSquare()) |