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PR-URL: https://github.com/nodejs/io.js/pull/2286 Reviewed-By: Roman Reiss <me@silverwind.io>
45 lines
1.2 KiB
JavaScript
45 lines
1.2 KiB
JavaScript
'use strict';
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var toPosInt = require('../number/to-pos-integer')
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, test = function (a, b) {}, desc, defineProperty
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, generate, mixin;
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try {
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Object.defineProperty(test, 'length', { configurable: true, writable: false,
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enumerable: false, value: 1 });
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} catch (ignore) {}
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if (test.length === 1) {
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// ES6
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desc = { configurable: true, writable: false, enumerable: false };
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defineProperty = Object.defineProperty;
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module.exports = function (fn, length) {
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length = toPosInt(length);
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if (fn.length === length) return fn;
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desc.value = length;
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return defineProperty(fn, 'length', desc);
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};
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} else {
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mixin = require('../object/mixin');
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generate = (function () {
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var cache = [];
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return function (l) {
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var args, i = 0;
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if (cache[l]) return cache[l];
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args = [];
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while (l--) args.push('a' + (++i).toString(36));
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return new Function('fn', 'return function (' + args.join(', ') +
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') { return fn.apply(this, arguments); };');
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};
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}());
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module.exports = function (src, length) {
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var target;
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length = toPosInt(length);
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if (src.length === length) return src;
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target = generate(length)(src);
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try { mixin(target, src); } catch (ignore) {}
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return target;
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};
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}
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