tsgammon-core/utils/decodeMoveString.js

A Backgammon library for Typescript, formerly developed as a part of tsgammon-ui

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.decodeMove = exports.decodeMoves = void 0;
/**
 * '1/2 2/3', '24/23 23/22' など駒の移動を表す文字列を、Moveの配列に変換する
 *
 * ※ Moveは相対表記なので、全てfrom<toとなるように変換される（上記はいずれも1/2 2/3扱い）
 *
 * '1/2/3'(一つの駒の連続移動) '1/2(2)'（複数の駒を同じように動かす）もサポートされる。
 *
 * @param s 駒の移動を表す文字列
 * @param boardSize デフォルトは24
 * @returns 正常に解析できたMoveの配列
 */
function decodeMoves(s, boardSize = 24) {
    const moves = s.trim().split(/\s+/);
    if (moves.length === 1 && moves[0] === '') {
        return [];
    }
    return moves
        .flatMap((move) => {
        // convert a/b(n) into a/b a/b ... a/b
        const match = move.match(/^(.+)\(([0-9]+)\)$/);
        if (match) {
            const n = Number(match[2]);
            return Array(n).fill(match[1]);
        }
        return move;
    })
        .flatMap((move) => {
        // convert a/b/c => a/b b/c
        const moves = move.split('/');
        if (moves.length <= 2) {
            return move;
        }
        return [...Array(moves.length - 1)].map((_, index) => moves[index] + '/' + moves[index + 1]);
    })
        .map((s) => s.trim())
        .map((s) => decodeMove(s, boardSize))
        .filter((m) => m.isValid);
}
exports.decodeMoves = decodeMoves;
function decodeMove(s, boardSize = 24) {
    // get from, to, isHit(*) e.g. 12/13*
    const match = s.match(/^([0-9]+|bar)\*?\/([0-9]+|off)(\*?)$/i);
    if (!match) {
        return { isValid: false };
    }
    const from = Number(match[1]);
    const to = Number(match[2]);
    const isHit = match[3] === '*';
    const isReenter = Number.isNaN(from);
    const isBearOff = Number.isNaN(to);
    if (isReenter && isBearOff) {
        return { isValid: false };
    }
    const MID = boardSize / 2;
    const BAR = boardSize + 1;
    const from_to = isReenter
        ? { from: 0, to: to < MID ? to : invert(to) }
        : isBearOff
            ? { from: MID < from ? from : invert(from), to: BAR }
            : from < to
                ? { from, to }
                : { from: invert(from), to: invert(to) };
    const pip = to - from;
    return Object.assign(Object.assign({ isValid: true }, from_to), { pip,
        isHit,
        isBearOff, isOverrun: false });
    function invert(pos) {
        return BAR - pos;
    }
}
exports.decodeMove = decodeMove;