Function concatComparators

lib/util/comparators.js:436–458

(c1, c2, ...cRest)

 * @returns {Comparator<T>} comparator
 */
const concatComparators = (c1, c2, ...cRest) => {
	if (cRest.length > 0) {
		const [c3, ...cRest2] = cRest;
		return concatComparators(c1, concatComparators(c2, c3, ...cRest2));
	}
	const cacheEntry = /** @type {Comparator<T>} */ (
		concatComparatorsCache.get(c1, c2)
	);
	if (cacheEntry !== undefined) return cacheEntry;
	/**
	 * Returns compare result.
	 * @param {T} a first value
	 * @param {T} b second value
	 * @returns {-1 | 0 | 1} compare result
	 */
	const result = (a, b) => {
		const res = c1(a, b);
		if (res !== 0) return res;
		return c2(a, b);
	};
	concatComparatorsCache.set(c1, c2, result);
	return result;
};

/**
 * Defines the selector type used by this module.