1 /* The contents of this file are subject to the Netscape Public 2 * License Version 1.1 (the "License"); you may not use this file 3 * except in compliance with the License. You may obtain a copy of 4 * the License at http://www.mozilla.org/NPL/ 5 * 6 * Software distributed under the License is distributed on an "AS 7 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or 8 * implied. See the License for the specific language governing 9 * rights and limitations under the License. 10 * 11 * The Original Code is Mozilla Communicator client code, released March 12 * 31, 1998. 13 * 14 * The Initial Developer of the Original Code is Netscape Communications 15 * Corporation. Portions created by Netscape are 16 * Copyright (C) 1998 Netscape Communications Corporation. All 17 * Rights Reserved. 18 * 19 * Contributor(s): 20 * 21 */ 22 /** 23 File Name: 12.10-1.js 24 ECMA Section: 12.10 The with statement 25 Description: 26 WithStatement : 27 with ( Expression ) Statement 28 29 The with statement adds a computed object to the front of the scope chain 30 of the current execution context, then executes a statement with this 31 augmented scope chain, then restores the scope chain. 32 33 Semantics 34 35 The production WithStatement : with ( Expression ) Statement is evaluated 36 as follows: 37 1. Evaluate Expression. 38 2. Call GetValue(Result(1)). 39 3. Call ToObject(Result(2)). 40 4. Add Result(3) to the front of the scope chain. 41 5. Evaluate Statement using the augmented scope chain from step 4. 42 6. Remove Result(3) from the front of the scope chain. 43 7. Return Result(5). 44 45 Discussion 46 Note that no matter how control leaves the embedded Statement, whether 47 normally or by some form of abrupt completion, the scope chain is always 48 restored to its former state. 49 50 Author: christine (at) netscape.com 51 Date: 12 november 1997 52 */ 53 54 var SECTION = "12.10-1"; 55 var VERSION = "ECMA_1"; 56 startTest(); 57 var TITLE = "The with statment"; 58 59 writeHeaderToLog( SECTION + " "+ TITLE); 60 61 var testcases = getTestCases(); 62 63 test(); 64 65 function test() { 66 for ( tc=0; tc < testcases.length; tc++ ) { 67 testcases[tc].passed = writeTestCaseResult( 68 testcases[tc].expect, 69 testcases[tc].actual, 70 testcases[tc].description +" = "+ 71 testcases[tc].actual ); 72 73 testcases[tc].reason += ( testcases[tc].passed ) ? "" : "wrong value "; 74 } 75 stopTest(); 76 return ( testcases ); 77 } 78 function getTestCases() { 79 var array = new Array(); 80 var item = 0; 81 82 // although the scope chain changes, the this value is immutable for a given 83 // execution context. 84 85 array[item++] = new TestCase( SECTION, 86 "with( new Number() ) { this +'' }", 87 "[object global]", 88 eval("with( new Number() ) { this +'' }") ); 89 90 // the object's functions and properties should override those of the 91 // global object. 92 93 array[item++] = new TestCase( 94 SECTION, 95 "var MYOB = new WithObject(true); with (MYOB) { parseInt() }", 96 true, 97 eval("var MYOB = new WithObject(true); with (MYOB) { parseInt() }") ); 98 99 array[item++] = new TestCase( 100 SECTION, 101 "var MYOB = new WithObject(false); with (MYOB) { NaN }", 102 false, 103 eval("var MYOB = new WithObject(false); with (MYOB) { NaN }") ); 104 105 array[item++] = new TestCase( 106 SECTION, 107 "var MYOB = new WithObject(NaN); with (MYOB) { Infinity }", 108 Number.NaN, 109 eval("var MYOB = new WithObject(NaN); with (MYOB) { Infinity }") ); 110 111 array[item++] = new TestCase( 112 SECTION, 113 "var MYOB = new WithObject(false); with (MYOB) { }; Infinity", 114 Number.POSITIVE_INFINITY, 115 eval("var MYOB = new WithObject(false); with (MYOB) { }; Infinity") ); 116 117 118 array[item++] = new TestCase( 119 SECTION, 120 "var MYOB = new WithObject(0); with (MYOB) { delete Infinity; Infinity }", 121 Number.POSITIVE_INFINITY, 122 eval("var MYOB = new WithObject(0); with (MYOB) { delete Infinity; Infinity }") ); 123 124 // let us leave the with block via a break. 125 126 array[item++] = new TestCase( 127 SECTION, 128 "var MYOB = new WithObject(0); while (true) { with (MYOB) { Infinity; break; } } Infinity", 129 Number.POSITIVE_INFINITY, 130 eval("var MYOB = new WithObject(0); while (true) { with (MYOB) { Infinity; break; } } Infinity") ); 131 132 return ( array ); 133 } 134 function WithObject( value ) { 135 this.prop1 = 1; 136 this.prop2 = new Boolean(true); 137 this.prop3 = "a string"; 138 this.value = value; 139 140 // now we will override global functions 141 142 this.parseInt = new Function( "return this.value" ); 143 this.NaN = value; 144 this.Infinity = value; 145 this.unescape = new Function( "return this.value" ); 146 this.escape = new Function( "return this.value" ); 147 this.eval = new Function( "return this.value" ); 148 this.parseFloat = new Function( "return this.value" ); 149 this.isNaN = new Function( "return this.value" ); 150 this.isFinite = new Function( "return this.value" ); 151 } 152
