2293 lines
70 KiB
TypeScript
2293 lines
70 KiB
TypeScript
/**
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* @license
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* Copyright (c) 2023, Jeff Hlywa (jhlywa@gmail.com)
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* 1. Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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export const WHITE: Color = "w";
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export const BLACK: Color = "b";
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export const PAWN = "p";
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export const KNIGHT = "n";
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export const BISHOP = "b";
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export const ROOK = "r";
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export const QUEEN = "q";
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export const KING = "k";
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export type Color = "w" | "b";
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export type PieceSymbol = "p" | "n" | "b" | "r" | "q" | "k";
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export const PIECE_SYMBOLS = ["p", "n", "b", "r", "q", "k"];
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// prettier-ignore
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export type Square =
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'a8' | 'b8' | 'c8' | 'd8' | 'e8' | 'f8' | 'g8' | 'h8' |
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'a7' | 'b7' | 'c7' | 'd7' | 'e7' | 'f7' | 'g7' | 'h7' |
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'a6' | 'b6' | 'c6' | 'd6' | 'e6' | 'f6' | 'g6' | 'h6' |
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'a5' | 'b5' | 'c5' | 'd5' | 'e5' | 'f5' | 'g5' | 'h5' |
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'a4' | 'b4' | 'c4' | 'd4' | 'e4' | 'f4' | 'g4' | 'h4' |
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'a3' | 'b3' | 'c3' | 'd3' | 'e3' | 'f3' | 'g3' | 'h3' |
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'a2' | 'b2' | 'c2' | 'd2' | 'e2' | 'f2' | 'g2' | 'h2' |
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'a1' | 'b1' | 'c1' | 'd1' | 'e1' | 'f1' | 'g1' | 'h1'
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export const DEFAULT_POSITION =
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"rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
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export type Piece = {
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color: Color;
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type: PieceSymbol;
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};
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type InternalMove = {
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color: Color;
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from: number;
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to: number;
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piece: PieceSymbol;
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captured?: PieceSymbol;
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promotion?: PieceSymbol;
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flags: number;
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};
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interface History {
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move: InternalMove;
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kings: Record<Color, number>;
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turn: Color;
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castling: Record<Color, number>;
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epSquare: number;
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halfMoves: number;
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moveNumber: number;
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}
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export type Move = {
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color: Color;
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from: Square;
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to: Square;
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piece: PieceSymbol;
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captured?: PieceSymbol;
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promotion?: PieceSymbol;
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flags: string;
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san: string;
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lan: string;
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before: string;
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after: string;
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};
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const EMPTY = -1;
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const FLAGS: Record<string, string> = {
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NORMAL: "n",
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CAPTURE: "c",
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BIG_PAWN: "b",
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EP_CAPTURE: "e",
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PROMOTION: "p",
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KSIDE_CASTLE: "k",
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QSIDE_CASTLE: "q",
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};
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// prettier-ignore
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export const SQUARES: Square[] = [
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'a8', 'b8', 'c8', 'd8', 'e8', 'f8', 'g8', 'h8',
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'a7', 'b7', 'c7', 'd7', 'e7', 'f7', 'g7', 'h7',
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'a6', 'b6', 'c6', 'd6', 'e6', 'f6', 'g6', 'h6',
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'a5', 'b5', 'c5', 'd5', 'e5', 'f5', 'g5', 'h5',
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'a4', 'b4', 'c4', 'd4', 'e4', 'f4', 'g4', 'h4',
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'a3', 'b3', 'c3', 'd3', 'e3', 'f3', 'g3', 'h3',
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'a2', 'b2', 'c2', 'd2', 'e2', 'f2', 'g2', 'h2',
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'a1', 'b1', 'c1', 'd1', 'e1', 'f1', 'g1', 'h1'
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]
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const BITS: Record<string, number> = {
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NORMAL: 1,
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CAPTURE: 2,
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BIG_PAWN: 4,
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EP_CAPTURE: 8,
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PROMOTION: 16,
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KSIDE_CASTLE: 32,
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QSIDE_CASTLE: 64,
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};
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/*
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* NOTES ABOUT 0x88 MOVE GENERATION ALGORITHM
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* ----------------------------------------------------------------------------
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* From https://github.com/jhlywa/chess.js/issues/230
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*
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* A lot of people are confused when they first see the internal representation
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* of chess.js. It uses the 0x88 Move Generation Algorithm which internally
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* stores the board as an 8x16 array. This is purely for efficiency but has a
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* couple of interesting benefits:
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*
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* 1. 0x88 offers a very inexpensive "off the board" check. Bitwise AND (&) any
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* square with 0x88, if the result is non-zero then the square is off the
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* board. For example, assuming a knight square A8 (0 in 0x88 notation),
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* there are 8 possible directions in which the knight can move. These
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* directions are relative to the 8x16 board and are stored in the
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* PIECE_OFFSETS map. One possible move is A8 - 18 (up one square, and two
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* squares to the left - which is off the board). 0 - 18 = -18 & 0x88 = 0x88
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* (because of two-complement representation of -18). The non-zero result
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* means the square is off the board and the move is illegal. Take the
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* opposite move (from A8 to C7), 0 + 18 = 18 & 0x88 = 0. A result of zero
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* means the square is on the board.
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*
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* 2. The relative distance (or difference) between two squares on a 8x16 board
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* is unique and can be used to inexpensively determine if a piece on a
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* square can attack any other arbitrary square. For example, let's see if a
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* pawn on E7 can attack E2. The difference between E7 (20) - E2 (100) is
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* -80. We add 119 to make the ATTACKS array index non-negative (because the
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* worst case difference is A8 - H1 = -119). The ATTACKS array contains a
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* bitmask of pieces that can attack from that distance and direction.
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* ATTACKS[-80 + 119=39] gives us 24 or 0b11000 in binary. Look at the
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* PIECE_MASKS map to determine the mask for a given piece type. In our pawn
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* example, we would check to see if 24 & 0x1 is non-zero, which it is
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* not. So, naturally, a pawn on E7 can't attack a piece on E2. However, a
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* rook can since 24 & 0x8 is non-zero. The only thing left to check is that
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* there are no blocking pieces between E7 and E2. That's where the RAYS
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* array comes in. It provides an offset (in this case 16) to add to E7 (20)
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* to check for blocking pieces. E7 (20) + 16 = E6 (36) + 16 = E5 (52) etc.
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*/
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// prettier-ignore
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// eslint-disable-next-line
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export const Ox88: Record<Square, number> = {
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a8: 0, b8: 1, c8: 2, d8: 3, e8: 4, f8: 5, g8: 6, h8: 7,
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a7: 16, b7: 17, c7: 18, d7: 19, e7: 20, f7: 21, g7: 22, h7: 23,
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a6: 32, b6: 33, c6: 34, d6: 35, e6: 36, f6: 37, g6: 38, h6: 39,
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a5: 48, b5: 49, c5: 50, d5: 51, e5: 52, f5: 53, g5: 54, h5: 55,
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a4: 64, b4: 65, c4: 66, d4: 67, e4: 68, f4: 69, g4: 70, h4: 71,
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a3: 80, b3: 81, c3: 82, d3: 83, e3: 84, f3: 85, g3: 86, h3: 87,
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a2: 96, b2: 97, c2: 98, d2: 99, e2: 100, f2: 101, g2: 102, h2: 103,
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a1: 112, b1: 113, c1: 114, d1: 115, e1: 116, f1: 117, g1: 118, h1: 119
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}
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const PAWN_OFFSETS = {
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b: [16, 32, 17, 15],
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w: [-16, -32, -17, -15],
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};
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const PIECE_OFFSETS = {
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n: [-18, -33, -31, -14, 18, 33, 31, 14],
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b: [-17, -15, 17, 15],
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r: [-16, 1, 16, -1],
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q: [-17, -16, -15, 1, 17, 16, 15, -1],
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k: [-17, -16, -15, 1, 17, 16, 15, -1],
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};
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// prettier-ignore
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const ATTACKS = [
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20, 0, 0, 0, 0, 0, 0, 24, 0, 0, 0, 0, 0, 0,20, 0,
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0,20, 0, 0, 0, 0, 0, 24, 0, 0, 0, 0, 0,20, 0, 0,
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0, 0,20, 0, 0, 0, 0, 24, 0, 0, 0, 0,20, 0, 0, 0,
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0, 0, 0,20, 0, 0, 0, 24, 0, 0, 0,20, 0, 0, 0, 0,
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0, 0, 0, 0,20, 0, 0, 24, 0, 0,20, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0,20, 2, 24, 2,20, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 2,53, 56, 53, 2, 0, 0, 0, 0, 0, 0,
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24,24,24,24,24,24,56, 0, 56,24,24,24,24,24,24, 0,
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0, 0, 0, 0, 0, 2,53, 56, 53, 2, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0,20, 2, 24, 2,20, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0,20, 0, 0, 24, 0, 0,20, 0, 0, 0, 0, 0,
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0, 0, 0,20, 0, 0, 0, 24, 0, 0, 0,20, 0, 0, 0, 0,
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0, 0,20, 0, 0, 0, 0, 24, 0, 0, 0, 0,20, 0, 0, 0,
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0,20, 0, 0, 0, 0, 0, 24, 0, 0, 0, 0, 0,20, 0, 0,
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20, 0, 0, 0, 0, 0, 0, 24, 0, 0, 0, 0, 0, 0,20
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];
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// prettier-ignore
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const RAYS = [
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17, 0, 0, 0, 0, 0, 0, 16, 0, 0, 0, 0, 0, 0, 15, 0,
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0, 17, 0, 0, 0, 0, 0, 16, 0, 0, 0, 0, 0, 15, 0, 0,
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0, 0, 17, 0, 0, 0, 0, 16, 0, 0, 0, 0, 15, 0, 0, 0,
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0, 0, 0, 17, 0, 0, 0, 16, 0, 0, 0, 15, 0, 0, 0, 0,
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0, 0, 0, 0, 17, 0, 0, 16, 0, 0, 15, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 17, 0, 16, 0, 15, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 17, 16, 15, 0, 0, 0, 0, 0, 0, 0,
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1, 1, 1, 1, 1, 1, 1, 0, -1, -1, -1,-1, -1, -1, -1, 0,
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0, 0, 0, 0, 0, 0,-15,-16,-17, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0,-15, 0,-16, 0,-17, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0,-15, 0, 0,-16, 0, 0,-17, 0, 0, 0, 0, 0,
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0, 0, 0,-15, 0, 0, 0,-16, 0, 0, 0,-17, 0, 0, 0, 0,
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0, 0,-15, 0, 0, 0, 0,-16, 0, 0, 0, 0,-17, 0, 0, 0,
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0,-15, 0, 0, 0, 0, 0,-16, 0, 0, 0, 0, 0,-17, 0, 0,
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-15, 0, 0, 0, 0, 0, 0,-16, 0, 0, 0, 0, 0, 0,-17
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];
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const PIECE_MASKS = { p: 0x1, n: 0x2, b: 0x4, r: 0x8, q: 0x10, k: 0x20 };
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const SYMBOLS = "pnbrqkPNBRQK";
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const PROMOTIONS: PieceSymbol[] = [KNIGHT, BISHOP, ROOK, QUEEN];
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const RANK_1 = 7;
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const RANK_2 = 6;
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/*
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* const RANK_3 = 5
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* const RANK_4 = 4
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* const RANK_5 = 3
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* const RANK_6 = 2
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*/
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const RANK_7 = 1;
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const RANK_8 = 0;
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const ROOKS = {
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w: [
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{ square: Ox88.a1, flag: BITS.QSIDE_CASTLE },
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{ square: Ox88.h1, flag: BITS.KSIDE_CASTLE },
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],
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b: [
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{ square: Ox88.a8, flag: BITS.QSIDE_CASTLE },
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{ square: Ox88.h8, flag: BITS.KSIDE_CASTLE },
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],
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};
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const SECOND_RANK = { b: RANK_7, w: RANK_2 };
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const TERMINATION_MARKERS = ["1-0", "0-1", "1/2-1/2", "*"];
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// Extracts the zero-based rank of an 0x88 square.
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export function rank(square: number): number {
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return square >> 4;
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}
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// Extracts the zero-based file of an 0x88 square.
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export function file(square: number): number {
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return square & 0xf;
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}
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function isDigit(c: string): boolean {
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return "0123456789".indexOf(c) !== -1;
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}
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// Converts a 0x88 square to algebraic notation.
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function algebraic(square: number): Square {
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const f = file(square);
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const r = rank(square);
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return ("abcdefgh".substring(f, f + 1) +
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"87654321".substring(r, r + 1)) as Square;
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}
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function swapColor(color: Color): Color {
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return color === WHITE ? BLACK : WHITE;
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}
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export function validateFen(fen: string) {
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// 1st criterion: 6 space-seperated fields?
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const tokens = fen.split(/\s+/);
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if (tokens.length !== 6) {
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return {
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ok: false,
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error: "Invalid FEN: must contain six space-delimited fields",
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};
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}
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// 2nd criterion: move number field is a integer value > 0?
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const moveNumber = parseInt(tokens[5], 10);
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if (isNaN(moveNumber) || moveNumber <= 0) {
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return {
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ok: false,
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error: "Invalid FEN: move number must be a positive integer",
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};
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}
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// 3rd criterion: half move counter is an integer >= 0?
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const halfMoves = parseInt(tokens[4], 10);
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if (isNaN(halfMoves) || halfMoves < 0) {
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return {
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ok: false,
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error: "Invalid FEN: half move counter number must be a non-negative integer",
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};
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}
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// 4th criterion: 4th field is a valid e.p.-string?
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if (!/^(-|[abcdefgh][36])$/.test(tokens[3])) {
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return {
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ok: false,
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error: "Invalid FEN: en-passant square is invalid",
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};
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}
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// 5th criterion: 3th field is a valid castle-string?
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if (/[^kKqQ-]/.test(tokens[2])) {
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return {
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ok: false,
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error: "Invalid FEN: castling availability is invalid",
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};
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}
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// 6th criterion: 2nd field is "w" (white) or "b" (black)?
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if (!/^(w|b)$/.test(tokens[1])) {
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return { ok: false, error: "Invalid FEN: side-to-move is invalid" };
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}
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// 7th criterion: 1st field contains 8 rows?
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const rows = tokens[0].split("/");
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if (rows.length !== 8) {
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return {
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ok: false,
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error: "Invalid FEN: piece data does not contain 8 '/'-delimited rows",
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};
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}
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// 8th criterion: every row is valid?
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for (let i = 0; i < rows.length; i++) {
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// check for right sum of fields AND not two numbers in succession
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let sumFields = 0;
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let previousWasNumber = false;
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for (let k = 0; k < rows[i].length; k++) {
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if (isDigit(rows[i][k])) {
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if (previousWasNumber) {
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return {
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ok: false,
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error: "Invalid FEN: piece data is invalid (consecutive number)",
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};
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}
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sumFields += parseInt(rows[i][k], 10);
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previousWasNumber = true;
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} else {
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if (!/^[prnbqkPRNBQK]$/.test(rows[i][k])) {
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return {
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ok: false,
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error: "Invalid FEN: piece data is invalid (invalid piece)",
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};
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}
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sumFields += 1;
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previousWasNumber = false;
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}
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}
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if (sumFields !== 8) {
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return {
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ok: false,
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error: "Invalid FEN: piece data is invalid (too many squares in rank)",
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};
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}
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}
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if (
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(tokens[3][1] == "3" && tokens[1] == "w") ||
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(tokens[3][1] == "6" && tokens[1] == "b")
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) {
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return { ok: false, error: "Invalid FEN: illegal en-passant square" };
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}
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const kings = [
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{ color: "white", regex: /K/g },
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{ color: "black", regex: /k/g },
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];
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for (const { color, regex } of kings) {
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if (!regex.test(tokens[0])) {
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return { ok: false, error: `Invalid FEN: missing ${color} king` };
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}
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if ((tokens[0].match(regex) || []).length > 1) {
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return { ok: false, error: `Invalid FEN: too many ${color} kings` };
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}
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}
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return { ok: true };
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}
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// this function is used to uniquely identify ambiguous moves
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function getDisambiguator(move: InternalMove, moves: InternalMove[]) {
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const from = move.from;
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const to = move.to;
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const piece = move.piece;
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let ambiguities = 0;
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let sameRank = 0;
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let sameFile = 0;
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for (let i = 0, len = moves.length; i < len; i++) {
|
|
const ambigFrom = moves[i].from;
|
|
const ambigTo = moves[i].to;
|
|
const ambigPiece = moves[i].piece;
|
|
|
|
/*
|
|
* if a move of the same piece type ends on the same to square, we'll need
|
|
* to add a disambiguator to the algebraic notation
|
|
*/
|
|
if (piece === ambigPiece && from !== ambigFrom && to === ambigTo) {
|
|
ambiguities++;
|
|
|
|
if (rank(from) === rank(ambigFrom)) {
|
|
sameRank++;
|
|
}
|
|
|
|
if (file(from) === file(ambigFrom)) {
|
|
sameFile++;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (ambiguities > 0) {
|
|
if (sameRank > 0 && sameFile > 0) {
|
|
/*
|
|
* if there exists a similar moving piece on the same rank and file as
|
|
* the move in question, use the square as the disambiguator
|
|
*/
|
|
return algebraic(from);
|
|
} else if (sameFile > 0) {
|
|
/*
|
|
* if the moving piece rests on the same file, use the rank symbol as the
|
|
* disambiguator
|
|
*/
|
|
return algebraic(from).charAt(1);
|
|
} else {
|
|
// else use the file symbol
|
|
return algebraic(from).charAt(0);
|
|
}
|
|
}
|
|
|
|
return "";
|
|
}
|
|
|
|
function addMove(
|
|
moves: InternalMove[],
|
|
color: Color,
|
|
from: number,
|
|
to: number,
|
|
piece: PieceSymbol,
|
|
captured: PieceSymbol | undefined = undefined,
|
|
flags: number = BITS.NORMAL
|
|
) {
|
|
const r = rank(to);
|
|
|
|
if (piece === PAWN && (r === RANK_1 || r === RANK_8)) {
|
|
for (let i = 0; i < PROMOTIONS.length; i++) {
|
|
const promotion = PROMOTIONS[i];
|
|
moves.push({
|
|
color,
|
|
from,
|
|
to,
|
|
piece,
|
|
captured,
|
|
promotion,
|
|
flags: flags | BITS.PROMOTION,
|
|
});
|
|
}
|
|
} else {
|
|
moves.push({
|
|
color,
|
|
from,
|
|
to,
|
|
piece,
|
|
captured,
|
|
flags,
|
|
});
|
|
}
|
|
}
|
|
|
|
function inferPieceType(san: string) {
|
|
let pieceType = san.charAt(0);
|
|
if (pieceType >= "a" && pieceType <= "h") {
|
|
const matches = san.match(/[a-h]\d.*[a-h]\d/);
|
|
if (matches) {
|
|
return undefined;
|
|
}
|
|
return PAWN;
|
|
}
|
|
pieceType = pieceType.toLowerCase();
|
|
if (pieceType === "o") {
|
|
return KING;
|
|
}
|
|
return pieceType as PieceSymbol;
|
|
}
|
|
|
|
// parses all of the decorators out of a SAN string
|
|
function strippedSan(move: string) {
|
|
return move.replace(/=/, "").replace(/[+#]?[?!]*$/, "");
|
|
}
|
|
|
|
export class Chess {
|
|
private _board = new Array<Piece>(128);
|
|
private _turn: Color = WHITE;
|
|
private _header: Record<string, string> = {};
|
|
private _kings: Record<Color, number> = { w: EMPTY, b: EMPTY };
|
|
private _epSquare = -1;
|
|
private _halfMoves = 0;
|
|
private _moveNumber = 0;
|
|
private _history: History[] = [];
|
|
private _comments: Record<string, string> = {};
|
|
private _castling: Record<Color, number> = { w: 0, b: 0 };
|
|
|
|
constructor(fen = DEFAULT_POSITION) {
|
|
this.load(fen);
|
|
}
|
|
|
|
clear(keepHeaders = false) {
|
|
this._board = new Array<Piece>(128);
|
|
this._kings = { w: EMPTY, b: EMPTY };
|
|
this._turn = WHITE;
|
|
this._castling = { w: 0, b: 0 };
|
|
this._epSquare = EMPTY;
|
|
this._halfMoves = 0;
|
|
this._moveNumber = 1;
|
|
this._history = [];
|
|
this._comments = {};
|
|
this._header = keepHeaders ? this._header : {};
|
|
this._updateSetup(this.fen());
|
|
}
|
|
|
|
load(fen: string, keepHeaders = false) {
|
|
let tokens = fen.split(/\s+/);
|
|
|
|
// append commonly omitted fen tokens
|
|
if (tokens.length >= 2 && tokens.length < 6) {
|
|
const adjustments = ["-", "-", "0", "1"];
|
|
fen = tokens
|
|
.concat(adjustments.slice(-(6 - tokens.length)))
|
|
.join(" ");
|
|
}
|
|
|
|
tokens = fen.split(/\s+/);
|
|
|
|
const { ok, error } = validateFen(fen);
|
|
if (!ok) {
|
|
throw new Error(error);
|
|
}
|
|
|
|
const position = tokens[0];
|
|
let square = 0;
|
|
|
|
this.clear(keepHeaders);
|
|
|
|
for (let i = 0; i < position.length; i++) {
|
|
const piece = position.charAt(i);
|
|
|
|
if (piece === "/") {
|
|
square += 8;
|
|
} else if (isDigit(piece)) {
|
|
square += parseInt(piece, 10);
|
|
} else {
|
|
const color = piece < "a" ? WHITE : BLACK;
|
|
this.put(
|
|
{ type: piece.toLowerCase() as PieceSymbol, color },
|
|
algebraic(square)
|
|
);
|
|
square++;
|
|
}
|
|
}
|
|
|
|
this._turn = tokens[1] as Color;
|
|
|
|
if (tokens[2].indexOf("K") > -1) {
|
|
this._castling.w |= BITS.KSIDE_CASTLE;
|
|
}
|
|
if (tokens[2].indexOf("Q") > -1) {
|
|
this._castling.w |= BITS.QSIDE_CASTLE;
|
|
}
|
|
if (tokens[2].indexOf("k") > -1) {
|
|
this._castling.b |= BITS.KSIDE_CASTLE;
|
|
}
|
|
if (tokens[2].indexOf("q") > -1) {
|
|
this._castling.b |= BITS.QSIDE_CASTLE;
|
|
}
|
|
|
|
this._epSquare = tokens[3] === "-" ? EMPTY : Ox88[tokens[3] as Square];
|
|
this._halfMoves = parseInt(tokens[4], 10);
|
|
this._moveNumber = parseInt(tokens[5], 10);
|
|
|
|
this._updateSetup(this.fen());
|
|
}
|
|
|
|
fen() {
|
|
let empty = 0;
|
|
let fen = "";
|
|
|
|
for (let i = Ox88.a8; i <= Ox88.h1; i++) {
|
|
if (this._board[i]) {
|
|
if (empty > 0) {
|
|
fen += empty;
|
|
empty = 0;
|
|
}
|
|
const { color, type: piece } = this._board[i];
|
|
|
|
fen +=
|
|
color === WHITE ? piece.toUpperCase() : piece.toLowerCase();
|
|
} else {
|
|
empty++;
|
|
}
|
|
|
|
if ((i + 1) & 0x88) {
|
|
if (empty > 0) {
|
|
fen += empty;
|
|
}
|
|
|
|
if (i !== Ox88.h1) {
|
|
fen += "/";
|
|
}
|
|
|
|
empty = 0;
|
|
i += 8;
|
|
}
|
|
}
|
|
|
|
let castling = "";
|
|
if (this._castling[WHITE] & BITS.KSIDE_CASTLE) {
|
|
castling += "K";
|
|
}
|
|
if (this._castling[WHITE] & BITS.QSIDE_CASTLE) {
|
|
castling += "Q";
|
|
}
|
|
if (this._castling[BLACK] & BITS.KSIDE_CASTLE) {
|
|
castling += "k";
|
|
}
|
|
if (this._castling[BLACK] & BITS.QSIDE_CASTLE) {
|
|
castling += "q";
|
|
}
|
|
|
|
// do we have an empty castling flag?
|
|
castling = castling || "-";
|
|
|
|
let epSquare = "-";
|
|
/*
|
|
* only print the ep square if en passant is a valid move (pawn is present
|
|
* and ep capture is not pinned)
|
|
*/
|
|
if (this._epSquare !== EMPTY) {
|
|
const bigPawnSquare =
|
|
this._epSquare + (this._turn === WHITE ? 16 : -16);
|
|
const squares = [bigPawnSquare + 1, bigPawnSquare - 1];
|
|
|
|
for (const square of squares) {
|
|
// is the square off the board?
|
|
if (square & 0x88) {
|
|
continue;
|
|
}
|
|
|
|
const color = this._turn;
|
|
|
|
// is there a pawn that can capture the epSquare?
|
|
if (
|
|
this._board[square]?.color === color &&
|
|
this._board[square]?.type === PAWN
|
|
) {
|
|
// if the pawn makes an ep capture, does it leave it's king in check?
|
|
this._makeMove({
|
|
color,
|
|
from: square,
|
|
to: this._epSquare,
|
|
piece: PAWN,
|
|
captured: PAWN,
|
|
flags: BITS.EP_CAPTURE,
|
|
});
|
|
const isLegal = !this._isKingAttacked(color);
|
|
this._undoMove();
|
|
|
|
// if ep is legal, break and set the ep square in the FEN output
|
|
if (isLegal) {
|
|
epSquare = algebraic(this._epSquare);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
return [
|
|
fen,
|
|
this._turn,
|
|
castling,
|
|
epSquare,
|
|
this._halfMoves,
|
|
this._moveNumber,
|
|
].join(" ");
|
|
}
|
|
|
|
/*
|
|
* Called when the initial board setup is changed with put() or remove().
|
|
* modifies the SetUp and FEN properties of the header object. If the FEN
|
|
* is equal to the default position, the SetUp and FEN are deleted the setup
|
|
* is only updated if history.length is zero, ie moves haven't been made.
|
|
*/
|
|
private _updateSetup(fen: string) {
|
|
if (this._history.length > 0) return;
|
|
|
|
if (fen !== DEFAULT_POSITION) {
|
|
this._header["SetUp"] = "1";
|
|
this._header["FEN"] = fen;
|
|
} else {
|
|
delete this._header["SetUp"];
|
|
delete this._header["FEN"];
|
|
}
|
|
}
|
|
|
|
reset() {
|
|
this.load(DEFAULT_POSITION);
|
|
}
|
|
|
|
get(square: Square) {
|
|
return this._board[Ox88[square]] ?? false;
|
|
}
|
|
|
|
put({ type, color }: { type: PieceSymbol; color: Color }, square: Square) {
|
|
// check for piece
|
|
if (SYMBOLS.indexOf(type.toLowerCase()) === -1) {
|
|
return false;
|
|
}
|
|
|
|
// check for valid square
|
|
if (!(square in Ox88)) {
|
|
return false;
|
|
}
|
|
|
|
const sq = Ox88[square];
|
|
|
|
// don't let the user place more than one king
|
|
if (
|
|
type == KING &&
|
|
!(this._kings[color] == EMPTY || this._kings[color] == sq)
|
|
) {
|
|
return false;
|
|
}
|
|
|
|
this._board[sq] = { type: type as PieceSymbol, color: color as Color };
|
|
|
|
if (type === KING) {
|
|
this._kings[color] = sq;
|
|
}
|
|
|
|
this._updateSetup(this.fen());
|
|
|
|
return true;
|
|
}
|
|
|
|
remove(square: Square) {
|
|
const piece = this.get(square);
|
|
delete this._board[Ox88[square]];
|
|
if (piece && piece.type === KING) {
|
|
this._kings[piece.color] = EMPTY;
|
|
}
|
|
|
|
this._updateSetup(this.fen());
|
|
|
|
return piece;
|
|
}
|
|
|
|
_attacked(color: Color, square: number) {
|
|
for (let i = Ox88.a8; i <= Ox88.h1; i++) {
|
|
// did we run off the end of the board
|
|
if (i & 0x88) {
|
|
i += 7;
|
|
continue;
|
|
}
|
|
|
|
// if empty square or wrong color
|
|
if (
|
|
this._board[i] === undefined ||
|
|
this._board[i].color !== color
|
|
) {
|
|
continue;
|
|
}
|
|
|
|
const piece = this._board[i];
|
|
const difference = i - square;
|
|
|
|
// skip - to/from square are the same
|
|
if (difference === 0) {
|
|
continue;
|
|
}
|
|
|
|
const index = difference + 119;
|
|
|
|
if (ATTACKS[index] & PIECE_MASKS[piece.type]) {
|
|
if (piece.type === PAWN) {
|
|
if (difference > 0) {
|
|
if (piece.color === WHITE) return true;
|
|
} else {
|
|
if (piece.color === BLACK) return true;
|
|
}
|
|
continue;
|
|
}
|
|
|
|
// if the piece is a knight or a king
|
|
if (piece.type === "n" || piece.type === "k") return true;
|
|
|
|
const offset = RAYS[index];
|
|
let j = i + offset;
|
|
|
|
let blocked = false;
|
|
while (j !== square) {
|
|
if (this._board[j] != null) {
|
|
blocked = true;
|
|
break;
|
|
}
|
|
j += offset;
|
|
}
|
|
|
|
if (!blocked) return true;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
private _isKingAttacked(color: Color) {
|
|
return this._attacked(swapColor(color), this._kings[color]);
|
|
}
|
|
|
|
isAttacked(square: Square, attackedBy: Color) {
|
|
return this._attacked(attackedBy, Ox88[square]);
|
|
}
|
|
|
|
isCheck() {
|
|
return this._isKingAttacked(this._turn);
|
|
}
|
|
|
|
inCheck() {
|
|
return this.isCheck();
|
|
}
|
|
|
|
isCheckmate() {
|
|
return this.isCheck() && this._moves().length === 0;
|
|
}
|
|
|
|
isStalemate() {
|
|
return !this.isCheck() && this._moves().length === 0;
|
|
}
|
|
|
|
isInsufficientMaterial() {
|
|
/*
|
|
* k.b. vs k.b. (of opposite colors) with mate in 1:
|
|
* 8/8/8/8/1b6/8/B1k5/K7 b - - 0 1
|
|
*
|
|
* k.b. vs k.n. with mate in 1:
|
|
* 8/8/8/8/1n6/8/B7/K1k5 b - - 2 1
|
|
*/
|
|
const pieces: Record<PieceSymbol, number> = {
|
|
b: 0,
|
|
n: 0,
|
|
r: 0,
|
|
q: 0,
|
|
k: 0,
|
|
p: 0,
|
|
};
|
|
const bishops = [];
|
|
let numPieces = 0;
|
|
let squareColor = 0;
|
|
|
|
for (let i = Ox88.a8; i <= Ox88.h1; i++) {
|
|
squareColor = (squareColor + 1) % 2;
|
|
if (i & 0x88) {
|
|
i += 7;
|
|
continue;
|
|
}
|
|
|
|
const piece = this._board[i];
|
|
if (piece) {
|
|
pieces[piece.type] =
|
|
piece.type in pieces ? pieces[piece.type] + 1 : 1;
|
|
if (piece.type === BISHOP) {
|
|
bishops.push(squareColor);
|
|
}
|
|
numPieces++;
|
|
}
|
|
}
|
|
|
|
// k vs. k
|
|
if (numPieces === 2) {
|
|
return true;
|
|
} else if (
|
|
// k vs. kn .... or .... k vs. kb
|
|
numPieces === 3 &&
|
|
(pieces[BISHOP] === 1 || pieces[KNIGHT] === 1)
|
|
) {
|
|
return true;
|
|
} else if (numPieces === pieces[BISHOP] + 2) {
|
|
// kb vs. kb where any number of bishops are all on the same color
|
|
let sum = 0;
|
|
const len = bishops.length;
|
|
for (let i = 0; i < len; i++) {
|
|
sum += bishops[i];
|
|
}
|
|
if (sum === 0 || sum === len) {
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
isThreefoldRepetition() {
|
|
const moves = [];
|
|
const positions: Record<string, number> = {};
|
|
let repetition = false;
|
|
|
|
while (true) {
|
|
const move = this._undoMove();
|
|
if (!move) break;
|
|
moves.push(move);
|
|
}
|
|
|
|
while (true) {
|
|
/*
|
|
* remove the last two fields in the FEN string, they're not needed when
|
|
* checking for draw by rep
|
|
*/
|
|
const fen = this.fen().split(" ").slice(0, 4).join(" ");
|
|
|
|
// has the position occurred three or move times
|
|
positions[fen] = fen in positions ? positions[fen] + 1 : 1;
|
|
if (positions[fen] >= 3) {
|
|
repetition = true;
|
|
}
|
|
|
|
const move = moves.pop();
|
|
|
|
if (!move) {
|
|
break;
|
|
} else {
|
|
this._makeMove(move);
|
|
}
|
|
}
|
|
|
|
return repetition;
|
|
}
|
|
|
|
isDraw() {
|
|
return (
|
|
this._halfMoves >= 100 || // 50 moves per side = 100 half moves
|
|
this.isStalemate() ||
|
|
this.isInsufficientMaterial() ||
|
|
this.isThreefoldRepetition()
|
|
);
|
|
}
|
|
|
|
isGameOver() {
|
|
return this.isCheckmate() || this.isStalemate() || this.isDraw();
|
|
}
|
|
|
|
moves(): string[];
|
|
moves({ square }: { square: Square }): string[];
|
|
moves({ piece }: { piece: PieceSymbol }): string[];
|
|
|
|
moves({ square, piece }: { square: Square; piece: PieceSymbol }): string[];
|
|
|
|
moves({ verbose, square }: { verbose: true; square?: Square }): Move[];
|
|
moves({ verbose, square }: { verbose: false; square?: Square }): string[];
|
|
moves({
|
|
verbose,
|
|
square,
|
|
}: {
|
|
verbose?: boolean;
|
|
square?: Square;
|
|
}): string[] | Move[];
|
|
|
|
moves({ verbose, piece }: { verbose: true; piece?: PieceSymbol }): Move[];
|
|
moves({
|
|
verbose,
|
|
piece,
|
|
}: {
|
|
verbose: false;
|
|
piece?: PieceSymbol;
|
|
}): string[];
|
|
moves({
|
|
verbose,
|
|
piece,
|
|
}: {
|
|
verbose?: boolean;
|
|
piece?: PieceSymbol;
|
|
}): string[] | Move[];
|
|
|
|
moves({
|
|
verbose,
|
|
square,
|
|
piece,
|
|
}: {
|
|
verbose: true;
|
|
square?: Square;
|
|
piece?: PieceSymbol;
|
|
}): Move[];
|
|
moves({
|
|
verbose,
|
|
square,
|
|
piece,
|
|
}: {
|
|
verbose: false;
|
|
square?: Square;
|
|
piece?: PieceSymbol;
|
|
}): string[];
|
|
moves({
|
|
verbose,
|
|
square,
|
|
piece,
|
|
}: {
|
|
verbose?: boolean;
|
|
square?: Square;
|
|
piece?: PieceSymbol;
|
|
}): string[] | Move[];
|
|
|
|
moves({ square, piece }: { square?: Square; piece?: PieceSymbol }): Move[];
|
|
|
|
moves({
|
|
verbose = false,
|
|
square = undefined,
|
|
piece = undefined,
|
|
}: { verbose?: boolean; square?: Square; piece?: PieceSymbol } = {}) {
|
|
const moves = this._moves({ square, piece });
|
|
|
|
if (verbose) {
|
|
return moves.map(move => this._makePretty(move));
|
|
} else {
|
|
return moves.map(move => this._moveToSan(move, moves));
|
|
}
|
|
}
|
|
|
|
_moves({
|
|
legal = true,
|
|
piece = undefined,
|
|
square = undefined,
|
|
}: {
|
|
legal?: boolean;
|
|
piece?: PieceSymbol;
|
|
square?: Square;
|
|
} = {}) {
|
|
const forSquare = square ? (square.toLowerCase() as Square) : undefined;
|
|
const forPiece = piece?.toLowerCase();
|
|
|
|
const moves: InternalMove[] = [];
|
|
const us = this._turn;
|
|
const them = swapColor(us);
|
|
|
|
let firstSquare = Ox88.a8;
|
|
let lastSquare = Ox88.h1;
|
|
let singleSquare = false;
|
|
|
|
// are we generating moves for a single square?
|
|
if (forSquare) {
|
|
// illegal square, return empty moves
|
|
if (!(forSquare in Ox88)) {
|
|
return [];
|
|
} else {
|
|
firstSquare = lastSquare = Ox88[forSquare];
|
|
singleSquare = true;
|
|
}
|
|
}
|
|
|
|
for (let from = firstSquare; from <= lastSquare; from++) {
|
|
// did we run off the end of the board
|
|
if (from & 0x88) {
|
|
from += 7;
|
|
continue;
|
|
}
|
|
|
|
// empty square or opponent, skip
|
|
if (!this._board[from] || this._board[from].color === them) {
|
|
continue;
|
|
}
|
|
const { type } = this._board[from];
|
|
|
|
let to: number;
|
|
if (type === PAWN) {
|
|
if (forPiece && forPiece !== type) continue;
|
|
|
|
// single square, non-capturing
|
|
to = from + PAWN_OFFSETS[us][0];
|
|
if (!this._board[to]) {
|
|
addMove(moves, us, from, to, PAWN);
|
|
|
|
// double square
|
|
to = from + PAWN_OFFSETS[us][1];
|
|
if (SECOND_RANK[us] === rank(from) && !this._board[to]) {
|
|
addMove(
|
|
moves,
|
|
us,
|
|
from,
|
|
to,
|
|
PAWN,
|
|
undefined,
|
|
BITS.BIG_PAWN
|
|
);
|
|
}
|
|
}
|
|
|
|
// pawn captures
|
|
for (let j = 2; j < 4; j++) {
|
|
to = from + PAWN_OFFSETS[us][j];
|
|
if (to & 0x88) continue;
|
|
|
|
if (this._board[to]?.color === them) {
|
|
addMove(
|
|
moves,
|
|
us,
|
|
from,
|
|
to,
|
|
PAWN,
|
|
this._board[to].type,
|
|
BITS.CAPTURE
|
|
);
|
|
} else if (to === this._epSquare) {
|
|
addMove(
|
|
moves,
|
|
us,
|
|
from,
|
|
to,
|
|
PAWN,
|
|
PAWN,
|
|
BITS.EP_CAPTURE
|
|
);
|
|
}
|
|
}
|
|
} else {
|
|
if (forPiece && forPiece !== type) continue;
|
|
|
|
for (
|
|
let j = 0, len = PIECE_OFFSETS[type].length;
|
|
j < len;
|
|
j++
|
|
) {
|
|
const offset = PIECE_OFFSETS[type][j];
|
|
to = from;
|
|
|
|
while (true) {
|
|
to += offset;
|
|
if (to & 0x88) break;
|
|
|
|
if (!this._board[to]) {
|
|
addMove(moves, us, from, to, type);
|
|
} else {
|
|
// own color, stop loop
|
|
if (this._board[to].color === us) break;
|
|
|
|
addMove(
|
|
moves,
|
|
us,
|
|
from,
|
|
to,
|
|
type,
|
|
this._board[to].type,
|
|
BITS.CAPTURE
|
|
);
|
|
break;
|
|
}
|
|
|
|
/* break, if knight or king */
|
|
if (type === KNIGHT || type === KING) break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* check for castling if we're:
|
|
* a) generating all moves, or
|
|
* b) doing single square move generation on the king's square
|
|
*/
|
|
|
|
if (forPiece === undefined || forPiece === KING) {
|
|
if (!singleSquare || lastSquare === this._kings[us]) {
|
|
// king-side castling
|
|
if (this._castling[us] & BITS.KSIDE_CASTLE) {
|
|
const castlingFrom = this._kings[us];
|
|
const castlingTo = castlingFrom + 2;
|
|
|
|
if (
|
|
!this._board[castlingFrom + 1] &&
|
|
!this._board[castlingTo] &&
|
|
!this._attacked(them, this._kings[us]) &&
|
|
!this._attacked(them, castlingFrom + 1) &&
|
|
!this._attacked(them, castlingTo)
|
|
) {
|
|
addMove(
|
|
moves,
|
|
us,
|
|
this._kings[us],
|
|
castlingTo,
|
|
KING,
|
|
undefined,
|
|
BITS.KSIDE_CASTLE
|
|
);
|
|
}
|
|
}
|
|
|
|
// queen-side castling
|
|
if (this._castling[us] & BITS.QSIDE_CASTLE) {
|
|
const castlingFrom = this._kings[us];
|
|
const castlingTo = castlingFrom - 2;
|
|
|
|
if (
|
|
!this._board[castlingFrom - 1] &&
|
|
!this._board[castlingFrom - 2] &&
|
|
!this._board[castlingFrom - 3] &&
|
|
!this._attacked(them, this._kings[us]) &&
|
|
!this._attacked(them, castlingFrom - 1) &&
|
|
!this._attacked(them, castlingTo)
|
|
) {
|
|
addMove(
|
|
moves,
|
|
us,
|
|
this._kings[us],
|
|
castlingTo,
|
|
KING,
|
|
undefined,
|
|
BITS.QSIDE_CASTLE
|
|
);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* return all pseudo-legal moves (this includes moves that allow the king
|
|
* to be captured)
|
|
*/
|
|
if (!legal) {
|
|
return moves;
|
|
}
|
|
|
|
// filter out illegal moves
|
|
const legalMoves = [];
|
|
|
|
for (let i = 0, len = moves.length; i < len; i++) {
|
|
this._makeMove(moves[i]);
|
|
if (!this._isKingAttacked(us)) {
|
|
legalMoves.push(moves[i]);
|
|
}
|
|
this._undoMove();
|
|
}
|
|
|
|
return legalMoves;
|
|
}
|
|
|
|
move(
|
|
move: string | { from: string; to: string; promotion?: string },
|
|
{ strict = false }: { strict?: boolean } = {}
|
|
) {
|
|
/*
|
|
* The move function can be called with in the following parameters:
|
|
*
|
|
* .move('Nxb7') <- argument is a case-sensitive SAN string
|
|
*
|
|
* .move({ from: 'h7', <- argument is a move object
|
|
* to :'h8',
|
|
* promotion: 'q' })
|
|
*
|
|
*
|
|
* An optional strict argument may be supplied to tell chess.js to
|
|
* strictly follow the SAN specification.
|
|
*/
|
|
|
|
let moveObj = null;
|
|
|
|
if (typeof move === "string") {
|
|
moveObj = this._moveFromSan(move, strict);
|
|
} else if (typeof move === "object") {
|
|
const moves = this._moves();
|
|
|
|
// convert the pretty move object to an ugly move object
|
|
for (let i = 0, len = moves.length; i < len; i++) {
|
|
if (
|
|
move.from === algebraic(moves[i].from) &&
|
|
move.to === algebraic(moves[i].to) &&
|
|
(!("promotion" in moves[i]) ||
|
|
move.promotion === moves[i].promotion)
|
|
) {
|
|
moveObj = moves[i];
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
// failed to find move
|
|
if (!moveObj) {
|
|
if (typeof move === "string") {
|
|
throw new Error(`Invalid move: ${move}`);
|
|
} else {
|
|
throw new Error(`Invalid move: ${JSON.stringify(move)}`);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* need to make a copy of move because we can't generate SAN after the move
|
|
* is made
|
|
*/
|
|
const prettyMove = this._makePretty(moveObj);
|
|
|
|
this._makeMove(moveObj);
|
|
|
|
return prettyMove;
|
|
}
|
|
|
|
_push(move: InternalMove) {
|
|
this._history.push({
|
|
move,
|
|
kings: { b: this._kings.b, w: this._kings.w },
|
|
turn: this._turn,
|
|
castling: { b: this._castling.b, w: this._castling.w },
|
|
epSquare: this._epSquare,
|
|
halfMoves: this._halfMoves,
|
|
moveNumber: this._moveNumber,
|
|
});
|
|
}
|
|
|
|
private _makeMove(move: InternalMove) {
|
|
const us = this._turn;
|
|
const them = swapColor(us);
|
|
this._push(move);
|
|
|
|
this._board[move.to] = this._board[move.from];
|
|
delete this._board[move.from];
|
|
|
|
// if ep capture, remove the captured pawn
|
|
if (move.flags & BITS.EP_CAPTURE) {
|
|
if (this._turn === BLACK) {
|
|
delete this._board[move.to - 16];
|
|
} else {
|
|
delete this._board[move.to + 16];
|
|
}
|
|
}
|
|
|
|
// if pawn promotion, replace with new piece
|
|
if (move.promotion) {
|
|
this._board[move.to] = { type: move.promotion, color: us };
|
|
}
|
|
|
|
// if we moved the king
|
|
if (this._board[move.to].type === KING) {
|
|
this._kings[us] = move.to;
|
|
|
|
// if we castled, move the rook next to the king
|
|
if (move.flags & BITS.KSIDE_CASTLE) {
|
|
const castlingTo = move.to - 1;
|
|
const castlingFrom = move.to + 1;
|
|
this._board[castlingTo] = this._board[castlingFrom];
|
|
delete this._board[castlingFrom];
|
|
} else if (move.flags & BITS.QSIDE_CASTLE) {
|
|
const castlingTo = move.to + 1;
|
|
const castlingFrom = move.to - 2;
|
|
this._board[castlingTo] = this._board[castlingFrom];
|
|
delete this._board[castlingFrom];
|
|
}
|
|
|
|
// turn off castling
|
|
this._castling[us] = 0;
|
|
}
|
|
|
|
// turn off castling if we move a rook
|
|
if (this._castling[us]) {
|
|
for (let i = 0, len = ROOKS[us].length; i < len; i++) {
|
|
if (
|
|
move.from === ROOKS[us][i].square &&
|
|
this._castling[us] & ROOKS[us][i].flag
|
|
) {
|
|
this._castling[us] ^= ROOKS[us][i].flag;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
// turn off castling if we capture a rook
|
|
if (this._castling[them]) {
|
|
for (let i = 0, len = ROOKS[them].length; i < len; i++) {
|
|
if (
|
|
move.to === ROOKS[them][i].square &&
|
|
this._castling[them] & ROOKS[them][i].flag
|
|
) {
|
|
this._castling[them] ^= ROOKS[them][i].flag;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
// if big pawn move, update the en passant square
|
|
if (move.flags & BITS.BIG_PAWN) {
|
|
if (us === BLACK) {
|
|
this._epSquare = move.to - 16;
|
|
} else {
|
|
this._epSquare = move.to + 16;
|
|
}
|
|
} else {
|
|
this._epSquare = EMPTY;
|
|
}
|
|
|
|
// reset the 50 move counter if a pawn is moved or a piece is captured
|
|
if (move.piece === PAWN) {
|
|
this._halfMoves = 0;
|
|
} else if (move.flags & (BITS.CAPTURE | BITS.EP_CAPTURE)) {
|
|
this._halfMoves = 0;
|
|
} else {
|
|
this._halfMoves++;
|
|
}
|
|
|
|
if (us === BLACK) {
|
|
this._moveNumber++;
|
|
}
|
|
|
|
this._turn = them;
|
|
}
|
|
|
|
undo() {
|
|
const move = this._undoMove();
|
|
return move ? this._makePretty(move) : null;
|
|
}
|
|
|
|
private _undoMove() {
|
|
const old = this._history.pop();
|
|
if (old === undefined) {
|
|
return null;
|
|
}
|
|
|
|
const move = old.move;
|
|
|
|
this._kings = old.kings;
|
|
this._turn = old.turn;
|
|
this._castling = old.castling;
|
|
this._epSquare = old.epSquare;
|
|
this._halfMoves = old.halfMoves;
|
|
this._moveNumber = old.moveNumber;
|
|
|
|
const us = this._turn;
|
|
const them = swapColor(us);
|
|
|
|
this._board[move.from] = this._board[move.to];
|
|
this._board[move.from].type = move.piece; // to undo any promotions
|
|
delete this._board[move.to];
|
|
|
|
if (move.captured) {
|
|
if (move.flags & BITS.EP_CAPTURE) {
|
|
// en passant capture
|
|
let index: number;
|
|
if (us === BLACK) {
|
|
index = move.to - 16;
|
|
} else {
|
|
index = move.to + 16;
|
|
}
|
|
this._board[index] = { type: PAWN, color: them };
|
|
} else {
|
|
// regular capture
|
|
this._board[move.to] = { type: move.captured, color: them };
|
|
}
|
|
}
|
|
|
|
if (move.flags & (BITS.KSIDE_CASTLE | BITS.QSIDE_CASTLE)) {
|
|
let castlingTo: number, castlingFrom: number;
|
|
if (move.flags & BITS.KSIDE_CASTLE) {
|
|
castlingTo = move.to + 1;
|
|
castlingFrom = move.to - 1;
|
|
} else {
|
|
castlingTo = move.to - 2;
|
|
castlingFrom = move.to + 1;
|
|
}
|
|
|
|
this._board[castlingTo] = this._board[castlingFrom];
|
|
delete this._board[castlingFrom];
|
|
}
|
|
|
|
return move;
|
|
}
|
|
|
|
pgn({
|
|
newline = "\n",
|
|
maxWidth = 0,
|
|
}: { newline?: string; maxWidth?: number } = {}) {
|
|
/*
|
|
* using the specification from http://www.chessclub.com/help/PGN-spec
|
|
* example for html usage: .pgn({ max_width: 72, newline_char: "<br />" })
|
|
*/
|
|
|
|
const result: string[] = [];
|
|
let headerExists = false;
|
|
|
|
/* add the PGN header information */
|
|
for (const i in this._header) {
|
|
/*
|
|
* TODO: order of enumerated properties in header object is not
|
|
* guaranteed, see ECMA-262 spec (section 12.6.4)
|
|
*/
|
|
result.push("[" + i + ' "' + this._header[i] + '"]' + newline);
|
|
headerExists = true;
|
|
}
|
|
|
|
if (headerExists && this._history.length) {
|
|
result.push(newline);
|
|
}
|
|
|
|
const appendComment = (moveString: string) => {
|
|
const comment = this._comments[this.fen()];
|
|
if (typeof comment !== "undefined") {
|
|
const delimiter = moveString.length > 0 ? " " : "";
|
|
moveString = `${moveString}${delimiter}{${comment}}`;
|
|
}
|
|
return moveString;
|
|
};
|
|
|
|
// pop all of history onto reversed_history
|
|
const reversedHistory = [];
|
|
while (this._history.length > 0) {
|
|
reversedHistory.push(this._undoMove());
|
|
}
|
|
|
|
const moves = [];
|
|
let moveString = "";
|
|
|
|
// special case of a commented starting position with no moves
|
|
if (reversedHistory.length === 0) {
|
|
moves.push(appendComment(""));
|
|
}
|
|
|
|
// build the list of moves. a move_string looks like: "3. e3 e6"
|
|
while (reversedHistory.length > 0) {
|
|
moveString = appendComment(moveString);
|
|
const move = reversedHistory.pop();
|
|
|
|
// make TypeScript stop complaining about move being undefined
|
|
if (!move) {
|
|
break;
|
|
}
|
|
|
|
// if the position started with black to move, start PGN with #. ...
|
|
if (!this._history.length && move.color === "b") {
|
|
const prefix = `${this._moveNumber}. ...`;
|
|
// is there a comment preceding the first move?
|
|
moveString = moveString ? `${moveString} ${prefix}` : prefix;
|
|
} else if (move.color === "w") {
|
|
// store the previous generated move_string if we have one
|
|
if (moveString.length) {
|
|
moves.push(moveString);
|
|
}
|
|
moveString = this._moveNumber + ".";
|
|
}
|
|
|
|
moveString =
|
|
moveString +
|
|
" " +
|
|
this._moveToSan(move, this._moves({ legal: true }));
|
|
this._makeMove(move);
|
|
}
|
|
|
|
// are there any other leftover moves?
|
|
if (moveString.length) {
|
|
moves.push(appendComment(moveString));
|
|
}
|
|
|
|
// is there a result?
|
|
if (typeof this._header.Result !== "undefined") {
|
|
moves.push(this._header.Result);
|
|
}
|
|
|
|
/*
|
|
* history should be back to what it was before we started generating PGN,
|
|
* so join together moves
|
|
*/
|
|
if (maxWidth === 0) {
|
|
return result.join("") + moves.join(" ");
|
|
}
|
|
|
|
// TODO (jah): huh?
|
|
const strip = function () {
|
|
if (result.length > 0 && result[result.length - 1] === " ") {
|
|
result.pop();
|
|
return true;
|
|
}
|
|
return false;
|
|
};
|
|
|
|
// NB: this does not preserve comment whitespace.
|
|
const wrapComment = function (width: number, move: string) {
|
|
for (const token of move.split(" ")) {
|
|
if (!token) {
|
|
continue;
|
|
}
|
|
if (width + token.length > maxWidth) {
|
|
while (strip()) {
|
|
width--;
|
|
}
|
|
result.push(newline);
|
|
width = 0;
|
|
}
|
|
result.push(token);
|
|
width += token.length;
|
|
result.push(" ");
|
|
width++;
|
|
}
|
|
if (strip()) {
|
|
width--;
|
|
}
|
|
return width;
|
|
};
|
|
|
|
// wrap the PGN output at max_width
|
|
let currentWidth = 0;
|
|
for (let i = 0; i < moves.length; i++) {
|
|
if (currentWidth + moves[i].length > maxWidth) {
|
|
if (moves[i].includes("{")) {
|
|
currentWidth = wrapComment(currentWidth, moves[i]);
|
|
continue;
|
|
}
|
|
}
|
|
// if the current move will push past max_width
|
|
if (currentWidth + moves[i].length > maxWidth && i !== 0) {
|
|
// don't end the line with whitespace
|
|
if (result[result.length - 1] === " ") {
|
|
result.pop();
|
|
}
|
|
|
|
result.push(newline);
|
|
currentWidth = 0;
|
|
} else if (i !== 0) {
|
|
result.push(" ");
|
|
currentWidth++;
|
|
}
|
|
result.push(moves[i]);
|
|
currentWidth += moves[i].length;
|
|
}
|
|
|
|
return result.join("");
|
|
}
|
|
|
|
header(...args: string[]) {
|
|
for (let i = 0; i < args.length; i += 2) {
|
|
if (
|
|
typeof args[i] === "string" &&
|
|
typeof args[i + 1] === "string"
|
|
) {
|
|
this._header[args[i]] = args[i + 1];
|
|
}
|
|
}
|
|
return this._header;
|
|
}
|
|
|
|
loadPgn(
|
|
pgn: string,
|
|
{
|
|
strict = false,
|
|
newlineChar = "\r?\n",
|
|
}: { strict?: boolean; newlineChar?: string } = {}
|
|
) {
|
|
function mask(str: string): string {
|
|
return str.replace(/\\/g, "\\");
|
|
}
|
|
|
|
function parsePgnHeader(header: string): { [key: string]: string } {
|
|
const headerObj: Record<string, string> = {};
|
|
const headers = header.split(new RegExp(mask(newlineChar)));
|
|
let key = "";
|
|
let value = "";
|
|
|
|
for (let i = 0; i < headers.length; i++) {
|
|
const regex = /^\s*\[\s*([A-Za-z]+)\s*"(.*)"\s*\]\s*$/;
|
|
key = headers[i].replace(regex, "$1");
|
|
value = headers[i].replace(regex, "$2");
|
|
if (key.trim().length > 0) {
|
|
headerObj[key] = value;
|
|
}
|
|
}
|
|
|
|
return headerObj;
|
|
}
|
|
|
|
// strip whitespace from head/tail of PGN block
|
|
pgn = pgn.trim();
|
|
|
|
/*
|
|
* RegExp to split header. Takes advantage of the fact that header and movetext
|
|
* will always have a blank line between them (ie, two newline_char's). Handles
|
|
* case where movetext is empty by matching newlineChar until end of string is
|
|
* matched - effectively trimming from the end extra newlineChar.
|
|
*
|
|
* With default newline_char, will equal:
|
|
* /^(\[((?:\r?\n)|.)*\])((?:\s*\r?\n){2}|(?:\s*\r?\n)*$)/
|
|
*/
|
|
const headerRegex = new RegExp(
|
|
"^(\\[((?:" +
|
|
mask(newlineChar) +
|
|
")|.)*\\])" +
|
|
"((?:\\s*" +
|
|
mask(newlineChar) +
|
|
"){2}|(?:\\s*" +
|
|
mask(newlineChar) +
|
|
")*$)"
|
|
);
|
|
|
|
// If no header given, begin with moves.
|
|
const headerRegexResults = headerRegex.exec(pgn);
|
|
const headerString = headerRegexResults
|
|
? headerRegexResults.length >= 2
|
|
? headerRegexResults[1]
|
|
: ""
|
|
: "";
|
|
|
|
// Put the board in the starting position
|
|
this.reset();
|
|
|
|
// parse PGN header
|
|
const headers = parsePgnHeader(headerString);
|
|
let fen = "";
|
|
|
|
for (const key in headers) {
|
|
// check to see user is including fen (possibly with wrong tag case)
|
|
if (key.toLowerCase() === "fen") {
|
|
fen = headers[key];
|
|
}
|
|
|
|
this.header(key, headers[key]);
|
|
}
|
|
|
|
/*
|
|
* the permissive parser should attempt to load a fen tag, even if it's the
|
|
* wrong case and doesn't include a corresponding [SetUp "1"] tag
|
|
*/
|
|
if (!strict) {
|
|
if (fen) {
|
|
this.load(fen, true);
|
|
}
|
|
} else {
|
|
/*
|
|
* strict parser - load the starting position indicated by [Setup '1']
|
|
* and [FEN position]
|
|
*/
|
|
if (headers["SetUp"] === "1") {
|
|
if (!("FEN" in headers)) {
|
|
throw new Error(
|
|
"Invalid PGN: FEN tag must be supplied with SetUp tag"
|
|
);
|
|
}
|
|
// second argument to load: don't clear the headers
|
|
this.load(headers["FEN"], true);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* NB: the regexes below that delete move numbers, recursive annotations,
|
|
* and numeric annotation glyphs may also match text in comments. To
|
|
* prevent this, we transform comments by hex-encoding them in place and
|
|
* decoding them again after the other tokens have been deleted.
|
|
*
|
|
* While the spec states that PGN files should be ASCII encoded, we use
|
|
* {en,de}codeURIComponent here to support arbitrary UTF8 as a convenience
|
|
* for modern users
|
|
*/
|
|
|
|
function toHex(s: string): string {
|
|
return Array.from(s)
|
|
.map(function (c) {
|
|
/*
|
|
* encodeURI doesn't transform most ASCII characters, so we handle
|
|
* these ourselves
|
|
*/
|
|
return c.charCodeAt(0) < 128
|
|
? c.charCodeAt(0).toString(16)
|
|
: encodeURIComponent(c).replace(/%/g, "").toLowerCase();
|
|
})
|
|
.join("");
|
|
}
|
|
|
|
function fromHex(s: string): string {
|
|
return s.length == 0
|
|
? ""
|
|
: decodeURIComponent(
|
|
"%" + (s.match(/.{1,2}/g) || []).join("%")
|
|
);
|
|
}
|
|
|
|
const encodeComment = function (s: string) {
|
|
s = s.replace(new RegExp(mask(newlineChar), "g"), " ");
|
|
return `{${toHex(s.slice(1, s.length - 1))}}`;
|
|
};
|
|
|
|
const decodeComment = function (s: string) {
|
|
if (s.startsWith("{") && s.endsWith("}")) {
|
|
return fromHex(s.slice(1, s.length - 1));
|
|
}
|
|
};
|
|
|
|
// delete header to get the moves
|
|
let ms = pgn
|
|
.replace(headerString, "")
|
|
.replace(
|
|
// encode comments so they don't get deleted below
|
|
new RegExp(`({[^}]*})+?|;([^${mask(newlineChar)}]*)`, "g"),
|
|
function (_match, bracket, semicolon) {
|
|
return bracket !== undefined
|
|
? encodeComment(bracket)
|
|
: " " + encodeComment(`{${semicolon.slice(1)}}`);
|
|
}
|
|
)
|
|
.replace(new RegExp(mask(newlineChar), "g"), " ");
|
|
|
|
// delete recursive annotation variations
|
|
const ravRegex = /(\([^()]+\))+?/g;
|
|
while (ravRegex.test(ms)) {
|
|
ms = ms.replace(ravRegex, "");
|
|
}
|
|
|
|
// delete move numbers
|
|
ms = ms.replace(/\d+\.(\.\.)?/g, "");
|
|
|
|
// delete ... indicating black to move
|
|
ms = ms.replace(/\.\.\./g, "");
|
|
|
|
/* delete numeric annotation glyphs */
|
|
ms = ms.replace(/\$\d+/g, "");
|
|
|
|
// trim and get array of moves
|
|
let moves = ms.trim().split(new RegExp(/\s+/));
|
|
|
|
// delete empty entries
|
|
moves = moves.filter(move => move !== "");
|
|
|
|
let result = "";
|
|
|
|
for (let halfMove = 0; halfMove < moves.length; halfMove++) {
|
|
const comment = decodeComment(moves[halfMove]);
|
|
if (comment !== undefined) {
|
|
this._comments[this.fen()] = comment;
|
|
continue;
|
|
}
|
|
|
|
const move = this._moveFromSan(moves[halfMove], strict);
|
|
|
|
// invalid move
|
|
if (move == null) {
|
|
// was the move an end of game marker
|
|
if (TERMINATION_MARKERS.indexOf(moves[halfMove]) > -1) {
|
|
result = moves[halfMove];
|
|
} else {
|
|
throw new Error(`Invalid move in PGN: ${moves[halfMove]}`);
|
|
}
|
|
} else {
|
|
// reset the end of game marker if making a valid move
|
|
result = "";
|
|
this._makeMove(move);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Per section 8.2.6 of the PGN spec, the Result tag pair must match match
|
|
* the termination marker. Only do this when headers are present, but the
|
|
* result tag is missing
|
|
*/
|
|
|
|
if (
|
|
result &&
|
|
Object.keys(this._header).length &&
|
|
!this._header["Result"]
|
|
) {
|
|
this.header("Result", result);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Convert a move from 0x88 coordinates to Standard Algebraic Notation
|
|
* (SAN)
|
|
*
|
|
* @param {boolean} strict Use the strict SAN parser. It will throw errors
|
|
* on overly disambiguated moves (see below):
|
|
*
|
|
* r1bqkbnr/ppp2ppp/2n5/1B1pP3/4P3/8/PPPP2PP/RNBQK1NR b KQkq - 2 4
|
|
* 4. ... Nge7 is overly disambiguated because the knight on c6 is pinned
|
|
* 4. ... Ne7 is technically the valid SAN
|
|
*/
|
|
|
|
private _moveToSan(move: InternalMove, moves: InternalMove[]) {
|
|
let output = "";
|
|
|
|
if (move.flags & BITS.KSIDE_CASTLE) {
|
|
output = "O-O";
|
|
} else if (move.flags & BITS.QSIDE_CASTLE) {
|
|
output = "O-O-O";
|
|
} else {
|
|
if (move.piece !== PAWN) {
|
|
const disambiguator = getDisambiguator(move, moves);
|
|
output += move.piece.toUpperCase() + disambiguator;
|
|
}
|
|
|
|
if (move.flags & (BITS.CAPTURE | BITS.EP_CAPTURE)) {
|
|
if (move.piece === PAWN) {
|
|
output += algebraic(move.from)[0];
|
|
}
|
|
output += "x";
|
|
}
|
|
|
|
output += algebraic(move.to);
|
|
|
|
if (move.promotion) {
|
|
output += "=" + move.promotion.toUpperCase();
|
|
}
|
|
}
|
|
|
|
this._makeMove(move);
|
|
if (this.isCheck()) {
|
|
if (this.isCheckmate()) {
|
|
output += "#";
|
|
} else {
|
|
output += "+";
|
|
}
|
|
}
|
|
this._undoMove();
|
|
|
|
return output;
|
|
}
|
|
|
|
// convert a move from Standard Algebraic Notation (SAN) to 0x88 coordinates
|
|
private _moveFromSan(move: string, strict = false): InternalMove | null {
|
|
// strip off any move decorations: e.g Nf3+?! becomes Nf3
|
|
const cleanMove = strippedSan(move);
|
|
|
|
let pieceType = inferPieceType(cleanMove);
|
|
let moves = this._moves({ legal: true, piece: pieceType });
|
|
|
|
// strict parser
|
|
for (let i = 0, len = moves.length; i < len; i++) {
|
|
if (cleanMove === strippedSan(this._moveToSan(moves[i], moves))) {
|
|
return moves[i];
|
|
}
|
|
}
|
|
|
|
// the strict parser failed
|
|
if (strict) {
|
|
return null;
|
|
}
|
|
|
|
let piece = undefined;
|
|
let matches = undefined;
|
|
let from = undefined;
|
|
let to = undefined;
|
|
let promotion = undefined;
|
|
|
|
/*
|
|
* The default permissive (non-strict) parser allows the user to parse
|
|
* non-standard chess notations. This parser is only run after the strict
|
|
* Standard Algebraic Notation (SAN) parser has failed.
|
|
*
|
|
* When running the permissive parser, we'll run a regex to grab the piece, the
|
|
* to/from square, and an optional promotion piece. This regex will
|
|
* parse common non-standard notation like: Pe2-e4, Rc1c4, Qf3xf7,
|
|
* f7f8q, b1c3
|
|
*
|
|
* NOTE: Some positions and moves may be ambiguous when using the permissive
|
|
* parser. For example, in this position: 6k1/8/8/B7/8/8/8/BN4K1 w - - 0 1,
|
|
* the move b1c3 may be interpreted as Nc3 or B1c3 (a disambiguated bishop
|
|
* move). In these cases, the permissive parser will default to the most
|
|
* basic interpretation (which is b1c3 parsing to Nc3).
|
|
*/
|
|
|
|
let overlyDisambiguated = false;
|
|
|
|
matches = cleanMove.match(
|
|
/([pnbrqkPNBRQK])?([a-h][1-8])x?-?([a-h][1-8])([qrbnQRBN])?/
|
|
// piece from to promotion
|
|
);
|
|
|
|
if (matches) {
|
|
piece = matches[1];
|
|
from = matches[2] as Square;
|
|
to = matches[3] as Square;
|
|
promotion = matches[4];
|
|
|
|
if (from.length == 1) {
|
|
overlyDisambiguated = true;
|
|
}
|
|
} else {
|
|
/*
|
|
* The [a-h]?[1-8]? portion of the regex below handles moves that may be
|
|
* overly disambiguated (e.g. Nge7 is unnecessary and non-standard when
|
|
* there is one legal knight move to e7). In this case, the value of
|
|
* 'from' variable will be a rank or file, not a square.
|
|
*/
|
|
|
|
matches = cleanMove.match(
|
|
/([pnbrqkPNBRQK])?([a-h]?[1-8]?)x?-?([a-h][1-8])([qrbnQRBN])?/
|
|
);
|
|
|
|
if (matches) {
|
|
piece = matches[1];
|
|
from = matches[2] as Square;
|
|
to = matches[3] as Square;
|
|
promotion = matches[4];
|
|
|
|
if (from.length == 1) {
|
|
overlyDisambiguated = true;
|
|
}
|
|
}
|
|
}
|
|
|
|
pieceType = inferPieceType(cleanMove);
|
|
moves = this._moves({
|
|
legal: true,
|
|
piece: piece ? (piece as PieceSymbol) : pieceType,
|
|
});
|
|
|
|
for (let i = 0, len = moves.length; i < len; i++) {
|
|
if (from && to) {
|
|
// hand-compare move properties with the results from our permissive regex
|
|
if (
|
|
(!piece || piece.toLowerCase() == moves[i].piece) &&
|
|
Ox88[from] == moves[i].from &&
|
|
Ox88[to] == moves[i].to &&
|
|
(!promotion ||
|
|
promotion.toLowerCase() == moves[i].promotion)
|
|
) {
|
|
return moves[i];
|
|
} else if (overlyDisambiguated) {
|
|
/*
|
|
* SPECIAL CASE: we parsed a move string that may have an unneeded
|
|
* rank/file disambiguator (e.g. Nge7). The 'from' variable will
|
|
*/
|
|
|
|
const square = algebraic(moves[i].from);
|
|
if (
|
|
(!piece || piece.toLowerCase() == moves[i].piece) &&
|
|
Ox88[to] == moves[i].to &&
|
|
(from == square[0] || from == square[1]) &&
|
|
(!promotion ||
|
|
promotion.toLowerCase() == moves[i].promotion)
|
|
) {
|
|
return moves[i];
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
return null;
|
|
}
|
|
|
|
ascii() {
|
|
let s = " +------------------------+\n";
|
|
for (let i = Ox88.a8; i <= Ox88.h1; i++) {
|
|
// display the rank
|
|
if (file(i) === 0) {
|
|
s += " " + "87654321"[rank(i)] + " |";
|
|
}
|
|
|
|
if (this._board[i]) {
|
|
const piece = this._board[i].type;
|
|
const color = this._board[i].color;
|
|
const symbol =
|
|
color === WHITE ? piece.toUpperCase() : piece.toLowerCase();
|
|
s += " " + symbol + " ";
|
|
} else {
|
|
s += " . ";
|
|
}
|
|
|
|
if ((i + 1) & 0x88) {
|
|
s += "|\n";
|
|
i += 8;
|
|
}
|
|
}
|
|
s += " +------------------------+\n";
|
|
s += " a b c d e f g h";
|
|
|
|
return s;
|
|
}
|
|
|
|
perft(depth: number) {
|
|
const moves = this._moves({ legal: false });
|
|
let nodes = 0;
|
|
const color = this._turn;
|
|
|
|
for (let i = 0, len = moves.length; i < len; i++) {
|
|
this._makeMove(moves[i]);
|
|
if (!this._isKingAttacked(color)) {
|
|
if (depth - 1 > 0) {
|
|
nodes += this.perft(depth - 1);
|
|
} else {
|
|
nodes++;
|
|
}
|
|
}
|
|
this._undoMove();
|
|
}
|
|
|
|
return nodes;
|
|
}
|
|
|
|
// pretty = external move object
|
|
private _makePretty(uglyMove: InternalMove): Move {
|
|
const { color, piece, from, to, flags, captured, promotion } = uglyMove;
|
|
|
|
let prettyFlags = "";
|
|
|
|
for (const flag in BITS) {
|
|
if (BITS[flag] & flags) {
|
|
prettyFlags += FLAGS[flag];
|
|
}
|
|
}
|
|
|
|
const fromAlgebraic = algebraic(from);
|
|
const toAlgebraic = algebraic(to);
|
|
|
|
const move: Move = {
|
|
color,
|
|
piece,
|
|
from: fromAlgebraic,
|
|
to: toAlgebraic,
|
|
san: this._moveToSan(uglyMove, this._moves({ legal: true })),
|
|
flags: prettyFlags,
|
|
lan: fromAlgebraic + toAlgebraic,
|
|
before: this.fen(),
|
|
after: "",
|
|
};
|
|
|
|
// generate the FEN for the 'after' key
|
|
this._makeMove(uglyMove);
|
|
move.after = this.fen();
|
|
this._undoMove();
|
|
|
|
if (captured) {
|
|
move.captured = captured;
|
|
}
|
|
if (promotion) {
|
|
move.promotion = promotion;
|
|
move.lan += promotion;
|
|
}
|
|
|
|
return move;
|
|
}
|
|
|
|
turn() {
|
|
return this._turn;
|
|
}
|
|
|
|
board(): (false | { square: Square; type: PieceSymbol; color: Color })[][] {
|
|
const output: (
|
|
| false
|
|
| {
|
|
square: Square;
|
|
type: PieceSymbol;
|
|
color: Color;
|
|
}
|
|
)[][] = [];
|
|
let row: (
|
|
| false
|
|
| {
|
|
square: Square;
|
|
type: PieceSymbol;
|
|
color: Color;
|
|
}
|
|
)[] = [];
|
|
|
|
for (let i = Ox88.a8; i <= Ox88.h1; i++) {
|
|
if (!this._board[i]) {
|
|
row.push(false);
|
|
} else {
|
|
row.push({
|
|
square: algebraic(i),
|
|
type: this._board[i].type,
|
|
color: this._board[i].color,
|
|
});
|
|
}
|
|
if ((i + 1) & 0x88) {
|
|
output.push(row);
|
|
row = [];
|
|
i += 8;
|
|
}
|
|
}
|
|
|
|
return output;
|
|
}
|
|
|
|
squareColor(square: Square): Color {
|
|
if (square in Ox88) {
|
|
const sq = Ox88[square];
|
|
return (rank(sq) + file(sq)) % 2 === 0 ? "w" : "b";
|
|
}
|
|
|
|
return null;
|
|
}
|
|
|
|
history(): string[];
|
|
history({ verbose }: { verbose: true }): Move[];
|
|
history({ verbose }: { verbose: false }): string[];
|
|
history({ verbose }: { verbose: boolean }): string[] | Move[];
|
|
history({ verbose = false }: { verbose?: boolean } = {}) {
|
|
const reversedHistory = [];
|
|
const moveHistory = [];
|
|
|
|
while (this._history.length > 0) {
|
|
reversedHistory.push(this._undoMove());
|
|
}
|
|
|
|
while (true) {
|
|
const move = reversedHistory.pop();
|
|
if (!move) {
|
|
break;
|
|
}
|
|
|
|
if (verbose) {
|
|
moveHistory.push(this._makePretty(move));
|
|
} else {
|
|
moveHistory.push(this._moveToSan(move, this._moves()));
|
|
}
|
|
this._makeMove(move);
|
|
}
|
|
|
|
return moveHistory;
|
|
}
|
|
|
|
private _pruneComments() {
|
|
const reversedHistory = [];
|
|
const currentComments: Record<string, string> = {};
|
|
|
|
const copyComment = (fen: string) => {
|
|
if (fen in this._comments) {
|
|
currentComments[fen] = this._comments[fen];
|
|
}
|
|
};
|
|
|
|
while (this._history.length > 0) {
|
|
reversedHistory.push(this._undoMove());
|
|
}
|
|
|
|
copyComment(this.fen());
|
|
|
|
while (true) {
|
|
const move = reversedHistory.pop();
|
|
if (!move) {
|
|
break;
|
|
}
|
|
this._makeMove(move);
|
|
copyComment(this.fen());
|
|
}
|
|
this._comments = currentComments;
|
|
}
|
|
|
|
getComment() {
|
|
return this._comments[this.fen()];
|
|
}
|
|
|
|
setComment(comment: string) {
|
|
this._comments[this.fen()] = comment
|
|
.replace("{", "[")
|
|
.replace("}", "]");
|
|
}
|
|
|
|
deleteComment() {
|
|
const comment = this._comments[this.fen()];
|
|
delete this._comments[this.fen()];
|
|
return comment;
|
|
}
|
|
|
|
getComments() {
|
|
this._pruneComments();
|
|
return Object.keys(this._comments).map((fen: string) => {
|
|
return { fen: fen, comment: this._comments[fen] };
|
|
});
|
|
}
|
|
|
|
deleteComments() {
|
|
this._pruneComments();
|
|
return Object.keys(this._comments).map(fen => {
|
|
const comment = this._comments[fen];
|
|
delete this._comments[fen];
|
|
return { fen: fen, comment: comment };
|
|
});
|
|
}
|
|
}
|