/**
* @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.MapUtils');
/**
* @namespace shaka.util.MapUtils
* @summary A set of map/object utility functions.
*/
/**
* Returns true if the map is empty; otherwise, returns false.
*
* @param {Object.<KEY, VALUE>} object
* @return {boolean}
* @template KEY,VALUE
*/
shaka.util.MapUtils.empty = function(object) {
return !object || Object.keys(object).length == 0;
};
/**
* Gets the map's values.
*
* @param {!Object.<KEY, VALUE>} object
* @return {!Array.<VALUE>}
* @template KEY,VALUE
*/
shaka.util.MapUtils.values = function(object) {
return Object.keys(object).map(function(key) { return object[key]; });
};
/**
* Converts the values in the given Map to a different value.
*
* @param {!Object.<KEY, VALUE>} object
* @param {function(VALUE, KEY=):OUTPUT} callback
* @return {!Object.<KEY, OUTPUT>}
* @template KEY,VALUE,OUTPUT
*/
shaka.util.MapUtils.map = function(object, callback) {
return Object.keys(object).reduce(function(ret, key) {
var value = object[key];
ret[key] = callback(value, key);
return ret;
}, {});
};
/**
* Creates a new object where the values are filtered out acording to a
* predicate.
*
* @param {!Object.<KEY, VALUE>} object
* @param {function(KEY, VALUE):boolean} callback
* @return {!Object.<KEY, VALUE>}
* @template KEY,VALUE
*/
shaka.util.MapUtils.filter = function(object, callback) {
return Object.keys(object).reduce(function(ret, key) {
if (callback(key, object[key]))
ret[key] = object[key];
return ret;
}, {});
};