gearsco.de
A chess library for Gleam
Implement `state` function
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-1
+11
-1
src/starfish.gleam
+11
-1
src/starfish.gleam
···
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import gleam/bool
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import gleam/result
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import starfish/internal/board
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import starfish/internal/game
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import starfish/internal/move
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···
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FiftyMoves
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}
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/// Returns the current game state: A win, draw or neither.
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pub fn state(game: Game) -> GameState {
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todo
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// TODO: Check for insufficient material and threefold repetition
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use <- bool.guard(game.half_moves >= 50, Draw(FiftyMoves))
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use <- bool.guard(move.any_legal(game), Continue)
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use <- bool.guard(!game.attack_information.in_check, Draw(Stalemate))
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case game.to_move {
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board.Black -> WhiteWin
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board.White -> BlackWin
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}
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}
+15
src/starfish/internal/move.gleam
+15
src/starfish/internal/move.gleam
···
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}
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}
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/// Checks whether any legal moves are possible without calculating every legal
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/// move beforehand.
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pub fn any_legal(game: Game) -> Bool {
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use any, square, position <- iv.index_fold(game.board, False)
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// If we've found legal moves already, we already know that there are some,
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// so no need to check for more.
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use <- bool.guard(any, any)
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case square {
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board.Occupied(piece:, colour:) if colour == game.to_move ->
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moves_for_piece(game, position, piece, []) != []
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board.Occupied(_, _) | board.Empty -> any
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}
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}
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fn move_is_valid_with_pins(
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from: Int,
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to: Int,
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test/starfish_test.gleam
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test/starfish_test.gleam
···
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let assert Error(Nil) = starfish.parse_long_algebraic_notation("Bxe4")
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}
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pub fn state_test() {
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assert "8/8/8/1q6/1K6/3q4/8/8 w - - 0 1"
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|> starfish.from_fen
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|> starfish.state
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== starfish.BlackWin
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assert "8/1B6/3np3/4k3/8/2B5/5R2/8 b - - 0 1"
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|> starfish.from_fen
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|> starfish.state
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== starfish.WhiteWin
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assert "8/8/8/1q1p2pp/8/KP3r2/5r2/8 w - - 0 1"
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|> starfish.from_fen
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|> starfish.state
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== starfish.Draw(starfish.Stalemate)
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assert "8/8/1RK5/8/7N/3rp3/3kb3/8 w - - 50 82"
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|> starfish.from_fen
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|> starfish.state
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== starfish.Draw(starfish.FiftyMoves)
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}
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fn perft_all(fen: String, expected: List(Int)) {
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expected
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|> list.index_map(fn(expected, index) { perft(fen, index + 1, expected) })