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


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.Value;
36
37 /**
38  * Represents a logical xor expression.
39  */
40 public class XorExpr extends BinaryExpr {
41   public XorExpr(Location location, Expr left, Expr right)
42   {
43     super(location, left, right);
44   }
45
46   public XorExpr(Expr left, Expr right)
47   {
48     super(left, right);
49   }
50
51   /**
52    * Returns true for a boolean.
53    */
54   public boolean isBoolean()
55   {
56     return true;
57   }
58
59   /**
60    * Evaluates the expression.
61    *
62    * @param env the calling environment.
63    *
64    * @return the expression value.
65    */
66   public Value eval(Env env)
67   {
68     if (_left.evalBoolean(env) != _right.evalBoolean(env))
69       return BooleanValue.TRUE;
70     else
71       return BooleanValue.FALSE;
72   }
73
74   /**
75    * Evaluates the expression.
76    *
77    * @param env the calling environment.
78    *
79    * @return the expression value.
80    */
81   public boolean evalBoolean(Env env)
82   {
83     return _left.evalBoolean(env) != _right.evalBoolean(env);
84   }
85
86   public String JavaDoc toString()
87   {
88     return "(" + _left + " xor " + _right + ")";
89   }
90 }
91
92
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