1 /*
2 * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/expr/DefaultTruthExpr.java,v 1.10 2006/02/05 21:47:40 elharo Exp $
3 * $Revision: 1.10 $
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: DefaultTruthExpr.java,v 1.10 2006/02/05 21:47:40 elharo Exp $
46 */
47
48
49
50 package org.jaxen.expr;
51
52 import java.util.List;
53
54 abstract class DefaultTruthExpr extends DefaultBinaryExpr
55 {
56 DefaultTruthExpr(Expr lhs,
57 Expr rhs)
58 {
59 super( lhs,
60 rhs );
61 }
62
63 public String toString()
64 {
65 return "[(DefaultTruthExpr): " + getLHS() + ", " + getRHS() + "]";
66 }
67
68 protected boolean bothAreSets(Object lhs,
69 Object rhs)
70 {
71 return ( lhs instanceof List
72 &&
73 rhs instanceof List );
74 }
75
76 protected boolean eitherIsSet(Object lhs,
77 Object rhs)
78 {
79 return ( lhs instanceof List
80 ||
81 rhs instanceof List );
82 }
83
84 protected boolean isSet(Object obj)
85 {
86 return ( obj instanceof List );
87 }
88
89 protected boolean setIsEmpty( List set )
90 {
91 return (set == null || set.size() == 0);
92 }
93
94 protected boolean eitherIsBoolean(Object lhs,
95 Object rhs)
96 {
97 return ( lhs instanceof Boolean
98 ||
99 rhs instanceof Boolean );
100 }
101
102 protected boolean bothAreBoolean(Object lhs,
103 Object rhs)
104 {
105 return ( lhs instanceof Boolean
106 &&
107 rhs instanceof Boolean );
108 }
109
110 protected boolean eitherIsNumber(Object lhs,
111 Object rhs)
112 {
113 return ( lhs instanceof Number
114 ||
115 rhs instanceof Number );
116 }
117
118 }
119