1 /* 2 * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/expr/DefaultTruthExpr.java,v 1.6 2003/06/29 18:05:40 ssanders Exp $ 3 * $Revision: 1.6 $ 4 * $Date: 2003/06/29 18:05:40 $ 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: DefaultTruthExpr.java,v 1.6 2003/06/29 18:05:40 ssanders Exp $ 60 */ 61 62 63 64 package org.jaxen.expr; 65 66 import java.util.List; 67 68 abstract class DefaultTruthExpr extends DefaultBinaryExpr 69 { 70 public DefaultTruthExpr(Expr lhs, 71 Expr rhs) 72 { 73 super( lhs, 74 rhs ); 75 } 76 77 public String toString() 78 { 79 return "[(DefaultTruthExpr): " + getLHS() + ", " + getRHS() + "]"; 80 } 81 82 protected boolean bothAreSets(Object lhs, 83 Object rhs) 84 { 85 return ( lhs instanceof List 86 && 87 rhs instanceof List ); 88 } 89 90 protected boolean eitherIsSet(Object lhs, 91 Object rhs) 92 { 93 return ( lhs instanceof List 94 || 95 rhs instanceof List ); 96 } 97 98 protected boolean isSet(Object obj) 99 { 100 return ( obj instanceof List ); 101 } 102 103 protected boolean setIsEmpty( List set ) 104 { 105 return (set == null || set.size() == 0); 106 } 107 108 protected boolean eitherIsBoolean(Object lhs, 109 Object rhs) 110 { 111 return ( lhs instanceof Boolean 112 || 113 rhs instanceof Boolean ); 114 } 115 116 protected boolean bothAreBoolean(Object lhs, 117 Object rhs) 118 { 119 return ( lhs instanceof Boolean 120 && 121 rhs instanceof Boolean ); 122 } 123 124 protected boolean eitherIsNumber(Object lhs, 125 Object rhs) 126 { 127 return ( lhs instanceof Number 128 || 129 rhs instanceof Number ); 130 } 131 132 protected boolean isNumber(Object obj) 133 { 134 return ( obj instanceof Number ); 135 } 136 137 protected boolean isString(Object obj) 138 { 139 return ( obj instanceof String ); 140 } 141 142 protected boolean isBoolean(Object obj) 143 { 144 return ( obj instanceof Boolean ); 145 } 146 } 147