Home | History | Annotate | Download | only in ExecutionContexts 
      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:          10.1.4-1.js
     24     ECMA Section:       10.1.4 Scope Chain and Identifier Resolution
     25     Description:
     26     Every execution context has associated with it a scope chain. This is
     27     logically a list of objects that are searched when binding an Identifier.
     28     When control enters an execution context, the scope chain is created and
     29     is populated with an initial set of objects, depending on the type of
     30     code. When control leaves the execution context, the scope chain is
     31     destroyed.
     32 
     33     During execution, the scope chain of the execution context is affected
     34     only by WithStatement. When execution enters a with block, the object
     35     specified in the with statement is added to the front of the scope chain.
     36     When execution leaves a with block, whether normally or via a break or
     37     continue statement, the object is removed from the scope chain. The object
     38     being removed will always be the first object in the scope chain.
     39 
     40     During execution, the syntactic production PrimaryExpression : Identifier
     41     is evaluated using the following algorithm:
     42 
     43     1.  Get the next object in the scope chain. If there isn't one, go to step 5.
     44     2.  Call the [[HasProperty]] method of Result(l), passing the Identifier as
     45         the property.
     46     3.  If Result(2) is true, return a value of type Reference whose base object
     47         is Result(l) and whose property name is the Identifier.
     48     4.  Go to step 1.
     49     5.  Return a value of type Reference whose base object is null and whose
     50         property name is the Identifier.
     51     The result of binding an identifier is always a value of type Reference with
     52     its member name component equal to the identifier string.
     53     Author:             christine (at) netscape.com
     54     Date:               12 november 1997
     55 */
     56     var SECTION = "10.1.4-2";
     57     var VERSION = "ECMA_1";
     58     startTest();
     59 
     60     writeHeaderToLog( SECTION + " Scope Chain and Identifier Resolution");
     61 
     62     var testcases = getTestCases();
     63 
     64     test();
     65 
     66 function test() {
     67     for ( tc=0; tc < testcases.length; tc++ ) {
     68 
     69         var MYOBJECT = new MyObject();
     70         var INPUT = 2;
     71         testcases[tc].description += "( "+INPUT +" )" ;
     72 
     73         with ( this ) {
     74             with ( MYOBJECT ) {
     75                 testcases[tc].actual = eval( INPUT );
     76                 testcases[tc].expect = Math.pow(INPUT,2);
     77             }
     78         }
     79 
     80         testcases[tc].passed = writeTestCaseResult(
     81                             testcases[tc].expect,
     82                             testcases[tc].actual,
     83                             testcases[tc].description +" = "+
     84                             testcases[tc].actual );
     85 
     86         testcases[tc].reason += ( testcases[tc].passed ) ? "" : "wrong value ";
     87     }
     88     stopTest();
     89     return ( testcases );
     90 }
     91 function getTestCases() {
     92     var array = new Array();
     93     var item = 0;
     94 
     95     array[item++] = new TestCase( "SECTION", "with MyObject, eval should return square of " );
     96 
     97     return ( array );
     98 }
     99 
    100 function MyObject() {
    101     this.eval = new Function( "x", "return(Math.pow(Number(x),2))" );
    102 }