35 lines
865 B
JavaScript
35 lines
865 B
JavaScript
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'use strict';
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/**
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* Copyright (c) 2013-present, Facebook, Inc.
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*
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* This source code is licensed under the MIT license found in the
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* LICENSE file in the root directory of this source tree.
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*
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* @typechecks
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*/
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var push = Array.prototype.push;
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/**
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* Applies a function to every item in an array and concatenates the resulting
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* arrays into a single flat array.
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*
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* @param {array} array
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* @param {function} fn
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* @return {array}
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*/
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function flatMapArray(array, fn) {
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var ret = [];
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for (var ii = 0; ii < array.length; ii++) {
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var result = fn.call(array, array[ii], ii);
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if (Array.isArray(result)) {
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push.apply(ret, result);
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} else if (result != null) {
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throw new TypeError('flatMapArray: Callback must return an array or null, ' + 'received "' + result + '" instead');
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}
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}
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return ret;
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}
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module.exports = flatMapArray;
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