memoizeII

/**
 * Memoize a function that accepts string/number arguments.
 *
 * @param {(...args: Array<string | number>) => unknown} func
 * @returns {(...args: Array<string | number>) => unknown}
 */
export default function memoize(func) {
	const cache = new Map();

	return function(...args) {
		const key = buildCacheKey(args);

		if (cache.has(key)) {
			return cache.get(key);
		}

		const result = func.apply(this, args);
		cache.set(key, result);
		return result;
	};
}

/**
 * Build a deterministic, type-safe key so 1 and '1' differ.
 *
 * @param {Array<string | number>} args
 * @returns {string}
 */
function buildCacheKey(args) {
	return args
		.map((arg) => `${typeof arg}:${String(arg).length}:${String(arg)}`)
		.join('|');
}

/**
Example:

function expensiveMul(a, b) {
	console.log('Computing...');
	return a * b;
}

const memoizedExpensiveMul = memoize(expensiveMul);

console.log(memoizedExpensiveMul(3, 7)); // Computing... 21
console.log(memoizedExpensiveMul(3, 7)); // 21
console.log(memoizedExpensiveMul(5, 8)); // Computing... 40
console.log(memoizedExpensiveMul(5, 8)); // 40
*/