src/core/len.js

/**
 * Len.
 *
 * @param {Iterable} iterable
 */
const len = (iterable) => {
	if (iterable.length !== undefined) return iterable.length;

	if (iterable.size !== undefined) return iterable.size;

	const it = iterable[Symbol.iterator]();

	let n = 0;

	while (!it.next().done) ++n;

	return n;
};

export default len;