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Java > Open Source Codes > com > caucho > quercus > expr > ArrayIsSetExpr


1 /*
2  * Copyright (c) 1998-2006 Caucho Technology -- all rights reserved
3  *
4  * This file is part of Resin(R) Open Source
5  *
6  * Each copy or derived work must preserve the copyright notice and this
7  * notice unmodified.
8  *
9  * Resin Open Source is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * Resin Open Source is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
17  * of NON-INFRINGEMENT. See the GNU General Public License for more
18  * details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with Resin Open Source; if not, write to the
22  *
23  * Free Software Foundation, Inc.
24  * 59 Temple Place, Suite 330
25  * Boston, MA 02111-1307 USA
26  *
27  * @author Scott Ferguson
28  */

29
30 package com.caucho.quercus.expr;
31
32 import com.caucho.quercus.Location;
33 import com.caucho.quercus.env.BooleanValue;
34 import com.caucho.quercus.env.Env;
35 import com.caucho.quercus.env.UnsetValue;
36 import com.caucho.quercus.env.Value;
37
38 /**
39  * Represents a PHP array is set expression.
40  */

41 public class ArrayIsSetExpr extends Expr {
42   protected final Expr _expr;
43   protected final Expr _index;
44
45   public ArrayIsSetExpr(Location location, Expr expr, Expr index)
46   {
47     super(location);
48     _expr = expr;
49     _index = index;
50   }
51
52   public ArrayIsSetExpr(Expr expr, Expr index)
53   {
54     _expr = expr;
55     _index = index;
56   }
57
58   public boolean isBoolean()
59   {
60     return true;
61   }
62
63   /**
64    * Evaluates the expression.
65    *
66    * @param env the calling environment.
67    *
68    * @return the expression value.
69    */

70   public Value eval(Env env)
71   {
72     return evalBoolean(env) ? BooleanValue.TRUE : BooleanValue.FALSE;
73   }
74
75   /**
76    * Evaluates the expression.
77    *
78    * @param env the calling environment.
79    *
80    * @return the expression value.
81    */

82   public boolean evalBoolean(Env env)
83   {
84     Value array = _expr.evalArg(env);
85     Value index = _index.eval(env);
86
87     return array.get(index) != UnsetValue.UNSET;
88   }
89
90   public String JavaDoc toString()
91   {
92     return "isset(" + _expr + "[" + _index + "])";
93   }
94 }
95
96
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