closure-builder
Version:
Simple Closure, Soy and JavaScript Build system
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JavaScript
// Copyright 2014 The Closure Library Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS-IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
/**
* @fileoverview Utilities for working with ES6 iterables.
*
* The goal is that this should be a replacement for goog.iter which uses
* a now non-standard approach to iterables.
*
* @see https://goo.gl/Rok5YQ
*/
goog.module('goog.labs.collections.iterables');
/**
* Get the iterator for an iterable.
* @param {!Iterable<VALUE>} iterable
* @return {!Iterator<VALUE>}
* @template VALUE
*/
exports.getIterator = function(iterable) {
return iterable[goog.global.Symbol.iterator]();
};
/**
* Call a function with every value of an iterable.
*
* Warning: this function will never halt if given an iterable that
* is never exhausted.
*
* @param {!Iterable<VALUE>} iterable
* @param {function(VALUE) : *} f
* @template VALUE
*/
exports.forEach = function(iterable, f) {
for (const elem of iterable) {
f(elem);
}
};
/**
* Maps the values of one iterable to create another iterable.
*
* When next() is called on the returned iterable, it will call the given
* function `f` with the next value of the given iterable
* `iterable` until the given iterable is exhausted.
*
* @param {!Iterable<VALUE>} iterable
* @param {function(this: THIS, VALUE): RESULT} f
* @return {!Iterable<RESULT>} The created iterable that gives the mapped
* values.
* @template THIS, VALUE, RESULT
*/
exports.map = function*(iterable, f) {
for (const elem of iterable) {
yield f(elem);
}
};
/**
* Filter elements from one iterator to create another iterable.
*
* When next() is called on the returned iterator, it will call next() on the
* given iterator and call the given function `f` with that value until `true`
* is returned or the given iterator is exhausted.
*
* @param {!Iterable<VALUE>} iterable
* @param {function(VALUE): boolean} f
* @return {!Iterable<VALUE>} The created iterable that gives the mapped
* values.
* @template VALUE
*/
exports.filter = function*(iterable, f) {
for (const elem of iterable) {
if (f(elem)) {
yield elem;
}
}
};