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- // TODO: disabled by default because of the conflict with another proposal
- 'use strict';
- var $ = require('../internals/export');
- var requireObjectCoercible = require('../internals/require-object-coercible');
- var toLength = require('../internals/to-length');
- var toInteger = require('../internals/to-integer');
- var fails = require('../internals/fails');
- var FORCED = fails(function () {
- return '𠮷'.at(0) !== '\uD842';
- });
- // `String.prototype.at` method
- // https://github.com/tc39/proposal-relative-indexing-method
- $({ target: 'String', proto: true, forced: FORCED }, {
- at: function at(index) {
- var S = String(requireObjectCoercible(this));
- var len = toLength(S.length);
- var relativeIndex = toInteger(index);
- var k = relativeIndex >= 0 ? relativeIndex : len + relativeIndex;
- return (k < 0 || k >= len) ? undefined : S.charAt(k);
- }
- });
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