com.google.javascript.jscomp.js.es6.array.flatmap.js Maven / Gradle / Ivy
/*
* Copyright 2018 The Closure Compiler Authors.
*
* 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 @suppress {uselessCode} */
'require util/polyfill';
$jscomp.polyfill('Array.prototype.flatMap', function(orig) {
if (orig) return orig;
/**
* Polyfills Array.prototype.flatMap.
*
* @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/flatMap
*
* @param {function(this: THIS, T, number, !IArrayLike): !Array} callback
* @param {THIS=} thisArg
* @return {!Array}
* @this {!IArrayLike}
* @template T, THIS, S
* @suppress {reportUnknownTypes}
*/
var flatMap = function(callback, thisArg) {
var mapped = [];
for (var i = 0; i < this.length; i++) {
var result = callback.call(thisArg, this[i], i, this);
if (Array.isArray(result)) {
mapped.push.apply(mapped, result);
} else {
// NOTE: The specification says the callback can return a non-Array.
// We intentionally don't include that in the type information on
// this function or the corresponding extern in order to encourage
// more readable code and avoid complex TTL in the type annotations,
// but we still want to behave correctly if the callback gives us a
// non-Array.
mapped.push(result);
}
}
return mapped;
};
return flatMap;
}, 'es9', 'es5');