/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */ /* This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ /* * Date: 2001-07-13 * * SUMMARY: Applying Function.prototype.call to the Function object itself * * * ECMA-262 15.3.4.4 Function.prototype.call (thisArg [,arg1 [,arg2,…] ] ) * * When applied to the Function object itself, thisArg should be ignored. * As explained by Waldemar (waldemar@netscape.com): * * Function.call(obj, "print(this)") is equivalent to invoking * Function("print(this)") with this set to obj. Now, Function("print(this)") * is equivalent to new Function("print(this)") (see 15.3.1.1), and the latter * ignores the this value that you passed it and constructs a function * (which we'll call F) which will print the value of the this that will be * passed in when F will be invoked. * * With the last set of () you're invoking F(), which means you're calling it * with no this value. When you don't provide a this value, it defaults to the * global object. * */ //----------------------------------------------------------------------------- var UBound = 0; var BUGNUMBER = '(none)'; var summary = 'Applying Function.prototype.call to the Function object itself'; var status = ''; var statusitems = []; var actual = ''; var actualvalues = []; var expect= ''; var expectedvalues = []; var self = this; // capture a reference to the global object var cnOBJECT_GLOBAL = self.toString(); var cnOBJECT_OBJECT = (new Object).toString(); var cnHello = 'Hello'; var cnRed = 'red'; var objTEST = {color:cnRed}; var f = new Function(); var g = new Function(); f = Function.call(self, 'return cnHello'); g = Function.call(objTEST, 'return cnHello'); status = 'Section A of test'; actual = f(); expect = cnHello; captureThis(); status = 'Section B of test'; actual = g(); expect = cnHello; captureThis(); f = Function.call(self, 'return this.toString()'); g = Function.call(objTEST, 'return this.toString()'); status = 'Section C of test'; actual = f(); expect = cnOBJECT_GLOBAL; captureThis(); status = 'Section D of test'; actual = g(); expect = cnOBJECT_GLOBAL; captureThis(); f = Function.call(self, 'return this.color'); g = Function.call(objTEST, 'return this.color'); status = 'Section E of test'; actual = f(); expect = undefined; captureThis(); status = 'Section F of test'; actual = g(); expect = undefined; captureThis(); //----------------------------------------------------------------------------- test(); //----------------------------------------------------------------------------- function captureThis() { statusitems[UBound] = status; actualvalues[UBound] = actual; expectedvalues[UBound] = expect; UBound++; } function test() { enterFunc ('test'); printBugNumber(BUGNUMBER); printStatus (summary); for (var i = 0; i < UBound; i++) { reportCompare(expectedvalues[i], actualvalues[i], statusitems[i]); } exitFunc ('test'); }