/**
* @license
* Copyright 2016 Google Inc.
*
* 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.
*/
goog.provide('shaka.util.ArrayUtils');
/**
* @namespace shaka.util.ArrayUtils
* @summary Array utility functions.
*/
/**
* Returns whether the two values contain the same value. This correctly
* handles comparisons involving NaN.
* @param {T} a
* @param {T} b
* @return {boolean}
* @template T
*/
shaka.util.ArrayUtils.defaultEquals = function(a, b) {
// NaN !== NaN, so we need to special case it.
if (typeof a === 'number' && typeof b === 'number' && isNaN(a) && isNaN(b)) {
return true;
}
return a === b;
};
/**
* Remove duplicate entries from an array. Order N^2, so use with caution.
* @param {!Array.<T>} array
* @param {function(T, T): boolean=} compareFn An optional function which
* will be used to compare items in the array.
* @return {!Array.<T>}
* @template T
*/
shaka.util.ArrayUtils.removeDuplicates = function(array, compareFn) {
if (!compareFn) {
compareFn = shaka.util.ArrayUtils.defaultEquals;
}
let result = [];
for (const item of array) {
const idx = shaka.util.ArrayUtils.indexOf(result, item, compareFn);
if (idx == -1) {
result.push(item);
}
}
return result;
};
/**
* Find an item in an array. For use when comparison of entries via == will
* not suffice.
* @param {!Array.<T>} array
* @param {T} value
* @param {function(T, T): boolean} compareFn A function which will be used to
* compare items in the array.
* @return {number} The index, or -1 if not found.
* @template T
*/
shaka.util.ArrayUtils.indexOf = function(array, value, compareFn) {
for (let i = 0; i < array.length; ++i) {
if (compareFn(array[i], value)) {
return i;
}
}
return -1;
};
/**
* Remove given element from array (assumes no duplicates).
* @param {!Array.<T>} array
* @param {T} element
* @template T
*/
shaka.util.ArrayUtils.remove = function(array, element) {
let index = array.indexOf(element);
if (index > -1) {
array.splice(index, 1);
}
};
/**
* Count the number of items in the list that pass the check function.
* @param {!Array.<T>} array
* @param {function(T):boolean} check
* @return {number}
* @template T
*/
shaka.util.ArrayUtils.count = function(array, check) {
let count = 0;
array.forEach(function(element) {
count += check(element) ? 1 : 0;
});
return count;
};