1 /*
2 * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/expr/DefaultEqualityExpr.java,v 1.14 2006/02/05 21:47:40 elharo Exp $
3 * $Revision: 1.14 $
4 * $Date: 2006/02/05 21:47:40 $
5 *
6 * ====================================================================
7 *
8 * Copyright 2000-2002 bob mcwhirter & James Strachan.
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions are
13 * met:
14 *
15 * * Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 *
18 * * Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 *
22 * * Neither the name of the Jaxen Project nor the names of its
23 * contributors may be used to endorse or promote products derived
24 * from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
27 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
29 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
30 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
31 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
32 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
33 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
34 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
35 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
36 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
37 *
38 * ====================================================================
39 * This software consists of voluntary contributions made by many
40 * individuals on behalf of the Jaxen Project and was originally
41 * created by bob mcwhirter <bob@werken.com> and
42 * James Strachan <jstrachan@apache.org>. For more information on the
43 * Jaxen Project, please see <http://www.jaxen.org/>.
44 *
45 * $Id: DefaultEqualityExpr.java,v 1.14 2006/02/05 21:47:40 elharo Exp $
46 */
47
48
49
50 package org.jaxen.expr;
51
52 import java.util.Iterator;
53 import java.util.List;
54 import org.jaxen.Context;
55 import org.jaxen.JaxenException;
56 import org.jaxen.Navigator;
57 import org.jaxen.function.BooleanFunction;
58 import org.jaxen.function.NumberFunction;
59 import org.jaxen.function.StringFunction;
60
61 abstract class DefaultEqualityExpr extends DefaultTruthExpr implements EqualityExpr
62 {
63 DefaultEqualityExpr( Expr lhs, Expr rhs )
64 {
65 super( lhs, rhs );
66 }
67
68 public String toString()
69 {
70 return "[(DefaultEqualityExpr): " + getLHS() + ", " + getRHS() + "]";
71 }
72
73 public Object evaluate( Context context ) throws JaxenException
74 {
75 Object lhsValue = getLHS().evaluate( context );
76 Object rhsValue = getRHS().evaluate( context );
77
78 if( lhsValue == null || rhsValue == null )
79 {
80 return Boolean.FALSE;
81 }
82
83 Navigator nav = context.getNavigator();
84
85 if( bothAreSets( lhsValue, rhsValue ) )
86 {
87 return evaluateSetSet( (List) lhsValue, (List) rhsValue, nav );
88 }
89 else if ( eitherIsSet( lhsValue, rhsValue ) )
90 {
91 if ( isSet( lhsValue ) )
92 {
93 return evaluateSetSet( (List) lhsValue, convertToList( rhsValue ), nav );
94 }
95 else
96 {
97 return evaluateSetSet( convertToList( lhsValue ), (List) rhsValue, nav );
98 }
99 }
100 else
101 {
102 return evaluateObjectObject( lhsValue, rhsValue, nav ) ? Boolean.TRUE : Boolean.FALSE;
103 }
104 }
105
106 private Boolean evaluateSetSet( List lhsSet, List rhsSet, Navigator nav )
107 {
108 if( setIsEmpty( lhsSet ) || setIsEmpty( rhsSet ) )
109 {
110 return Boolean.FALSE;
111 }
112
113 for( Iterator lhsIterator = lhsSet.iterator(); lhsIterator.hasNext(); )
114 {
115 Object lhs = lhsIterator.next();
116
117 for( Iterator rhsIterator = rhsSet.iterator(); rhsIterator.hasNext(); )
118 {
119 Object rhs = rhsIterator.next();
120
121 if( evaluateObjectObject( lhs, rhs, nav ) )
122 {
123 return Boolean.TRUE;
124 }
125 }
126 }
127
128 return Boolean.FALSE;
129 }
130
131 private boolean evaluateObjectObject( Object lhs, Object rhs, Navigator nav )
132 {
133 if( eitherIsBoolean( lhs, rhs ) )
134 {
135 return evaluateObjectObject( BooleanFunction.evaluate( lhs, nav ),
136 BooleanFunction.evaluate( rhs, nav ) );
137 }
138 else if( eitherIsNumber( lhs, rhs ) )
139 {
140 return evaluateObjectObject( NumberFunction.evaluate( lhs,
141 nav ),
142 NumberFunction.evaluate( rhs,
143 nav ) );
144 }
145 else
146 {
147 return evaluateObjectObject( StringFunction.evaluate( lhs,
148 nav ),
149 StringFunction.evaluate( rhs,
150 nav ) );
151 }
152 }
153
154 protected abstract boolean evaluateObjectObject( Object lhs, Object rhs );
155 }