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


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.Env;
34 import com.caucho.quercus.env.Value;
35
36 /**
37  * Represents a PHP right shift expression.
38  */
39 public class RightShiftExpr extends BinaryExpr {
40   public RightShiftExpr(Location location, Expr left, Expr right)
41   {
42     super(location, left, right);
43   }
44
45   public RightShiftExpr(Expr left, Expr right)
46   {
47     super(left, right);
48   }
49
50   /**
51    * Returns true for a long expression.
52    */
53   public boolean isLong()
54   {
55     return true;
56   }
57
58   /**
59    * Evaluates the expression.
60    *
61    * @param env the calling environment.
62    *
63    * @return the expression value.
64    */
65   public Value eval(Env env)
66   {
67     Value lValue = _left.eval(env);
68     Value rValue = _right.eval(env);
69
70     return lValue.rshift(rValue);
71   }
72
73   /**
74    * Evaluates the expression as a long.
75    *
76    * @param env the calling environment.
77    *
78    * @return the expression value.
79    */
80   public long evalLong(Env env)
81   {
82     Value lValue = _left.eval(env);
83     Value rValue = _right.eval(env);
84
85     return lValue.toLong() >> rValue.toLong();
86   }
87
88   public String JavaDoc toString()
89   {
90     return "(" + _left + " >> " + _right + ")";
91   }
92 }
93
94
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