1 /*
2 * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/expr/DefaultEqualityExpr.java,v 1.13 2005/06/28 13:44:44 elharo Exp $
3 * $Revision: 1.13 $
4 * $Date: 2005/06/28 13:44:44 $
5 *
6 * ====================================================================
7 *
8 * Copyright (C) 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
13 * are met:
14 *
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions, and the following disclaimer.
17 *
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions, and the disclaimer that follows
20 * these conditions in the documentation and/or other materials
21 * provided with the distribution.
22 *
23 * 3. The name "Jaxen" must not be used to endorse or promote products
24 * derived from this software without prior written permission. For
25 * written permission, please contact license@jaxen.org.
26 *
27 * 4. Products derived from this software may not be called "Jaxen", nor
28 * may "Jaxen" appear in their name, without prior written permission
29 * from the Jaxen Project Management (pm@jaxen.org).
30 *
31 * In addition, we request (but do not require) that you include in the
32 * end-user documentation provided with the redistribution and/or in the
33 * software itself an acknowledgement equivalent to the following:
34 * "This product includes software developed by the
35 * Jaxen Project <http://www.jaxen.org/>."
36 * Alternatively, the acknowledgment may be graphical using the logos
37 * available at http://www.jaxen.org/
38 *
39 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
40 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
41 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
42 * DISCLAIMED. IN NO EVENT SHALL THE Jaxen AUTHORS OR THE PROJECT
43 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
45 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
46 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
47 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
48 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
49 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50 * SUCH DAMAGE.
51 *
52 * ====================================================================
53 * This software consists of voluntary contributions made by many
54 * individuals on behalf of the Jaxen Project and was originally
55 * created by bob mcwhirter <bob@werken.com> and
56 * James Strachan <jstrachan@apache.org>. For more information on the
57 * Jaxen Project, please see <http://www.jaxen.org/>.
58 *
59 * $Id: DefaultEqualityExpr.java,v 1.13 2005/06/28 13:44:44 elharo Exp $
60 */
61
62
63
64 package org.jaxen.expr;
65
66 import java.util.Iterator;
67 import java.util.List;
68 import org.jaxen.Context;
69 import org.jaxen.JaxenException;
70 import org.jaxen.Navigator;
71 import org.jaxen.function.BooleanFunction;
72 import org.jaxen.function.NumberFunction;
73 import org.jaxen.function.StringFunction;
74
75 abstract class DefaultEqualityExpr extends DefaultTruthExpr implements EqualityExpr
76 {
77 DefaultEqualityExpr( Expr lhs, Expr rhs )
78 {
79 super( lhs, rhs );
80 }
81
82 public String toString()
83 {
84 return "[(DefaultEqualityExpr): " + getLHS() + ", " + getRHS() + "]";
85 }
86
87 public Object evaluate( Context context ) throws JaxenException
88 {
89 Object lhsValue = getLHS().evaluate( context );
90 Object rhsValue = getRHS().evaluate( context );
91
92 if( lhsValue == null || rhsValue == null )
93 {
94 return Boolean.FALSE;
95 }
96
97 Navigator nav = context.getNavigator();
98
99 if( bothAreSets( lhsValue, rhsValue ) )
100 {
101 return evaluateSetSet( (List) lhsValue, (List) rhsValue, nav );
102 }
103 else if ( eitherIsSet( lhsValue, rhsValue ) )
104 {
105 if ( isSet( lhsValue ) )
106 {
107 return evaluateSetSet( (List) lhsValue, convertToList( rhsValue ), nav );
108 }
109 else
110 {
111 return evaluateSetSet( convertToList( lhsValue ), (List) rhsValue, nav );
112 }
113 }
114 else
115 {
116 return evaluateObjectObject( lhsValue, rhsValue, nav ) ? Boolean.TRUE : Boolean.FALSE;
117 }
118 }
119
120 private Boolean evaluateSetSet( List lhsSet, List rhsSet, Navigator nav )
121 {
122 if( setIsEmpty( lhsSet ) || setIsEmpty( rhsSet ) )
123 {
124 return Boolean.FALSE;
125 }
126
127 for( Iterator lhsIterator = lhsSet.iterator(); lhsIterator.hasNext(); )
128 {
129 Object lhs = lhsIterator.next();
130
131 for( Iterator rhsIterator = rhsSet.iterator(); rhsIterator.hasNext(); )
132 {
133 Object rhs = rhsIterator.next();
134
135 if( evaluateObjectObject( lhs, rhs, nav ) )
136 {
137 return Boolean.TRUE;
138 }
139 }
140 }
141
142 return Boolean.FALSE;
143 }
144
145 private boolean evaluateObjectObject( Object lhs, Object rhs, Navigator nav )
146 {
147 if( eitherIsBoolean( lhs, rhs ) )
148 {
149 return evaluateObjectObject( BooleanFunction.evaluate( lhs, nav ),
150 BooleanFunction.evaluate( rhs, nav ) );
151 }
152 else if( eitherIsNumber( lhs, rhs ) )
153 {
154 return evaluateObjectObject( NumberFunction.evaluate( lhs,
155 nav ),
156 NumberFunction.evaluate( rhs,
157 nav ) );
158 }
159 else
160 {
161 return evaluateObjectObject( StringFunction.evaluate( lhs,
162 nav ),
163 StringFunction.evaluate( rhs,
164 nav ) );
165 }
166 }
167
168 protected abstract boolean evaluateObjectObject( Object lhs, Object rhs );
169 }