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Java > Open Source Codes > org > jacorb > trading > constraint > AndNode


1
2 // Copyright (C) 1998-1999
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// Object Oriented Concepts, Inc.
4

5 // **********************************************************************
6
//
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// Copyright (c) 1997
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// Mark Spruiell (mark@intellisoft.com)
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//
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// See the COPYING file for more information
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//
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// **********************************************************************
13

14 package org.jacorb.trading.constraint;
15
16 import java.io.*;
17
18
19 /** Represents logical "AND" */
20 public class AndNode extends ExprNode
21 {
22   private ExprNode m_left;
23   private ExprNode m_right;
24
25
26   private AndNode()
27   {
28   }
29
30
31   public AndNode(ExprNode left, ExprNode right)
32   {
33     m_left = left;
34     m_right = right;
35
36     setType(new ValueType(ValueType.BOOLEAN));
37   }
38
39
40   public void print(PrintStream ps)
41   {
42     ps.println("AndNode: type = " + getType());
43     ps.println("Left node:");
44     m_left.print(ps);
45     ps.println("Right node:");
46     m_right.print(ps);
47   }
48
49
50   public Value evaluate(PropertySource source)
51     throws MissingPropertyException
52   {
53     Value result = null;
54
55     int id = getType().getId();
56
57     Value left, right;
58
59     left = m_left.evaluate(source);
60     Boolean JavaDoc l = (Boolean JavaDoc)left.getValue();
61
62       // only evaluate the right side if the answer isn't already
63
// known after evaluating the left side
64
if (l.booleanValue()) {
65       right = m_right.evaluate(source);
66       Boolean JavaDoc r = (Boolean JavaDoc)right.getValue();
67       result = ValueFactory.createBoolean(r.booleanValue());
68     }
69     else
70       result = ValueFactory.createBoolean(false);
71
72     return result;
73   }
74 }
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