mirror of https://github.com/tc39/test262.git
68 lines
1.7 KiB
JavaScript
68 lines
1.7 KiB
JavaScript
/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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/*---
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defines: [getJSClass, findType, findClass, isObject]
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allow_unused: True
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---*/
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/*
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* Date: 14 Mar 2001
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*
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* SUMMARY: Utility functions for testing objects -
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*
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* Suppose obj is an instance of a native type, e.g. Number.
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* Then obj.toString() invokes Number.prototype.toString().
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* We would also like to access Object.prototype.toString().
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*
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* The difference is this: suppose obj = new Number(7).
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* Invoking Number.prototype.toString() on this just returns 7.
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* Object.prototype.toString() on this returns '[object Number]'.
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*
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* The getJSClass() function returns 'Number', the [[Class]] property of obj.
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* See ECMA-262 Edition 3, 13-Oct-1999, Section 8.6.2
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*/
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//-----------------------------------------------------------------------------
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var cnNoObject = 'Unexpected Error!!! Parameter to this function must be an object';
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var cnNoClass = 'Unexpected Error!!! Cannot find Class property';
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var cnObjectToString = Object.prototype.toString;
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var GLOBAL = 'global';
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// checks that it's safe to call findType()
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function getJSClass(obj)
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{
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if (isObject(obj))
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return findClass(findType(obj));
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return cnNoObject;
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}
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function findType(obj)
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{
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return cnObjectToString.apply(obj);
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}
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// given '[object Number]', return 'Number'
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function findClass(sType)
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{
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var re = /^\[.*\s+(\w+)\s*\]$/;
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var a = sType.match(re);
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if (a && a[1])
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return a[1];
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return cnNoClass;
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}
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function isObject(obj)
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{
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return obj instanceof Object;
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}
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