| 'use strict'; |
| var toObject = require('../internals/to-object'); |
| var toAbsoluteIndex = require('../internals/to-absolute-index'); |
| var lengthOfArrayLike = require('../internals/length-of-array-like'); |
| var deletePropertyOrThrow = require('../internals/delete-property-or-throw'); |
|
|
| var min = Math.min; |
|
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| |
| |
| |
| module.exports = [].copyWithin || function copyWithin(target , start ) { |
| var O = toObject(this); |
| var len = lengthOfArrayLike(O); |
| var to = toAbsoluteIndex(target, len); |
| var from = toAbsoluteIndex(start, len); |
| var end = arguments.length > 2 ? arguments[2] : undefined; |
| var count = min((end === undefined ? len : toAbsoluteIndex(end, len)) - from, len - to); |
| var inc = 1; |
| if (from < to && to < from + count) { |
| inc = -1; |
| from += count - 1; |
| to += count - 1; |
| } |
| while (count-- > 0) { |
| if (from in O) O[to] = O[from]; |
| else deletePropertyOrThrow(O, to); |
| to += inc; |
| from += inc; |
| } return O; |
| }; |
|
|