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Java > Open Source Codes > com > caucho > quercus > program > ForStatement


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.program;
31
32 import com.caucho.quercus.Location;
33 import com.caucho.quercus.env.BreakValue;
34 import com.caucho.quercus.env.ContinueValue;
35 import com.caucho.quercus.env.Env;
36 import com.caucho.quercus.env.Value;
37 import com.caucho.quercus.expr.Expr;
38
39 /**
40  * Represents a for statement.
41  */
42 public class ForStatement extends Statement {
43   protected final Expr _init;
44   protected final Expr _test;
45   protected final Expr _incr;
46   protected final Statement _block;
47
48   public ForStatement(Location location, Expr init, Expr test, Expr incr, Statement block)
49   {
50     super(location);
51
52     _init = init;
53     _test = test;
54     _incr = incr;
55
56     _block = block;
57   }
58
59   public Value execute(Env env)
60   {
61     try {
62       if (_init != null)
63         _init.eval(env);
64
65       while (_test == null || _test.evalBoolean(env)) {
66         env.checkTimeout();
67
68         Value value = _block.execute(env);
69
70         if (value == null || value instanceof ContinueValue) {
71         }
72         else if (value instanceof BreakValue)
73           return null;
74         else
75           return value;
76
77         if (_incr != null)
78           _incr.eval(env);
79       }
80     }
81     catch (RuntimeException JavaDoc t) {
82       rethrow(t, RuntimeException JavaDoc.class);
83     }
84
85     return null;
86   }
87 }
88
89
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