Source: lib/util/array_utils.js

  1. /**
  2.  * @license
  3.  * Copyright 2016 Google Inc.
  4.  *
  5.  * Licensed under the Apache License, Version 2.0 (the "License");
  6.  * you may not use this file except in compliance with the License.
  7.  * You may obtain a copy of the License at
  8.  *
  9.  *     http://www.apache.org/licenses/LICENSE-2.0
  10.  *
  11.  * Unless required by applicable law or agreed to in writing, software
  12.  * distributed under the License is distributed on an "AS IS" BASIS,
  13.  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14.  * See the License for the specific language governing permissions and
  15.  * limitations under the License.
  16.  */
  18. goog.provide('shaka.util.ArrayUtils');
  21. /**
  22.  * @namespace shaka.util.ArrayUtils
  23.  * @summary Array utility functions.
  24.  */
  27. /**
  28.  * Remove duplicate entries from an array.  Order N^2, so use with caution.
  29.  * @param {!Array.<T>} array
  30.  * @param {function(T, T): boolean=} opt_compareFn An optional function which
  31.  *   will be used to compare items in the array.
  32.  * @return {!Array.<T>}
  33.  * @template T
  34.  */
  35. shaka.util.ArrayUtils.removeDuplicates = function(array, opt_compareFn) {
  36.   var result = [];
  37.   for (var i = 0; i < array.length; ++i) {
  38.     var matchFound = false;
  39.     for (var j = 0; j < result.length; ++j) {
  40.       matchFound = opt_compareFn ? opt_compareFn(array[i], result[j]) :
  41.                                    array[i] === result[j];
  42.       if (matchFound) break;
  43.     }
  44.     if (!matchFound) {
  45.       result.push(array[i]);
  46.     }
  47.   }
  48.   return result;
  49. };
  52. /**
  53.  * Find an item in an array.  For use when comparison of entries via == will
  54.  * not suffice.
  55.  * @param {!Array.<T>} array
  56.  * @param {T} value
  57.  * @param {function(T, T): boolean} compareFn A function which will be used to
  58.  *   compare items in the array.
  59.  * @return {number} The index, or -1 if not found.
  60.  * @template T
  61.  */
  62. shaka.util.ArrayUtils.indexOf = function(array, value, compareFn) {
  63.   for (var i = 0; i < array.length; ++i) {
  64.     if (compareFn(array[i], value)) {
  65.       return i;
  66.     }
  67.   }
  68.   return -1;
  69. };
  72. /**
  73.  * Remove given element from array (assumes no duplicates).
  74.  * @param {!Array.<T>} array
  75.  * @param {T} element
  76.  * @template T
  77.  */
  78. shaka.util.ArrayUtils.remove = function(array, element) {
  79.   var index = array.indexOf(element);
  80.   if (index > -1)
  81.     array.splice(index, 1);
  82. };