com.google.javascript.jscomp.js.es6.array.copywithin.js Maven / Gradle / Ivy
/*
* Copyright 2016 The Closure Compiler Authors.
*
* 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.
*/
'require util/polyfill';
$jscomp.polyfill('Array.prototype.copyWithin', function(orig) {
// requires strict mode to throw for invalid `this` or params
'use strict';
if (orig) return orig;
/**
* Copies elements from one part of the array to another.
*
* @this {!IArrayLike}
* @param {number} target Start index to copy elements to.
* @param {number} start Start index to copy elements from.
* @param {number=} opt_end Index from which to end copying.
* @return {!IArrayLike} The array, with the copy performed in-place.
* @template VALUE
*/
var polyfill = function(target, start, opt_end) {
var len = this.length;
target = toInteger(target);
start = toInteger(start);
var end = opt_end === undefined ? len : toInteger(opt_end);
var to = target < 0 ? Math.max(len + target, 0) : Math.min(target, len);
var from = start < 0 ? Math.max(len + start, 0) : Math.min(start, len);
var final = end < 0 ? Math.max(len + end, 0) : Math.min(end, len);
if (to < from) {
while (from < final) {
if (from in this) {
this[to++] = this[from++];
} else {
delete this[to++];
from++;
}
}
} else {
final = Math.min(final, len + from - to);
to += final - from;
while (final > from) {
if (--final in this) {
this[--to] = this[final];
} else {
delete this[--to];
}
}
}
return this;
};
/**
* @param {number} arg
* @return {number}
*/
function toInteger(arg) {
var n = Number(arg);
if (n === Infinity || n === -Infinity) {
return n;
}
return n | 0;
}
return polyfill;
}, 'es6', 'es3');