/**
* @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.Iterables');
/**
* Recreations of Array-like functions so that they work on any iterable
* type.
* @final
*/
shaka.util.Iterables = class {
/**
* @param {!Iterable.<FROM>} iterable
* @param {function(FROM):TO} mapping
* @return {!Iterable.<TO>}
* @template FROM,TO
*/
static map(iterable, mapping) {
const array = [];
for (const x of iterable) { array.push(mapping(x)); }
return array;
}
/**
* @param {!Iterable.<T>} iterable
* @param {function(T):boolean} test
* @return {boolean}
* @template T
*/
static every(iterable, test) {
for (const x of iterable) {
if (!test(x)) { return false; }
}
return true;
}
/**
* @param {!Iterable.<T>} iterable
* @param {function(T):boolean} test
* @return {boolean}
* @template T
*/
static some(iterable, test) {
for (const x of iterable) {
if (test(x)) { return true; }
}
return false;
}
/**
* Iterate over an iterable object and return only the items that |filter|
* returns true for.
*
* @param {!Iterable.<T>} iterable
* @param {function(T):boolean} filter
* @return {!Array.<T>}
* @template T
*/
static filter(iterable, filter) {
const out = [];
for (const x of iterable) {
if (filter(x)) { out.push(x); }
}
return out;
}
};