webpack/lib/util/IterableHelpers.js

Packs CommonJs/AMD modules for the browser. Allows to split your codebase into multiple bundles, which can be loaded on demand. Support loaders to preprocess files, i.e. json, jsx, es7, css, less, ... and your custom stuff.

/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Tobias Koppers @sokra
*/

"use strict";

/**
 * @template T
 * @param {Iterable<T>} set a set
 * @returns {T | undefined} last item
 */
const last = set => {
	let last;
	for (const item of set) last = item;
	return last;
};

/**
 * @template T
 * @param {Iterable<T>} iterable iterable
 * @param {function(T): boolean} filter predicate
 * @returns {boolean} true, if some items match the filter predicate
 */
const someInIterable = (iterable, filter) => {
	for (const item of iterable) {
		if (filter(item)) return true;
	}
	return false;
};

/**
 * @template T
 * @param {Iterable<T>} iterable an iterable
 * @returns {number} count of items
 */
const countIterable = iterable => {
	let i = 0;
	// eslint-disable-next-line no-unused-vars
	for (const _ of iterable) i++;
	return i;
};

exports.last = last;
exports.someInIterable = someInIterable;
exports.countIterable = countIterable;