1 /* 2 * $Header: /cvsroot/jaxen/jaxen/src/java/main/org/jaxen/expr/DefaultTruthExpr.java,v 1.4 2002/04/26 17:17:34 jstrachan Exp $ 3 * $Revision: 1.4 $ 4 * $Date: 2002/04/26 17:17:34 $ 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 1.4 2002/04/26 17:17:34 jstrachan Exp $ 60 */ 61 62 63 64 package org.jaxen.expr; 65 66 import org.jaxen.Context; 67 import org.jaxen.util.SingleObjectIterator; 68 69 import java.util.List; 70 import java.util.Iterator; 71 import java.util.Collections; 72 73 abstract class DefaultTruthExpr extends DefaultBinaryExpr 74 { DefaultTruthExpr(Expr lhs, Expr rhs)75 public DefaultTruthExpr(Expr lhs, 76 Expr rhs) 77 { 78 super( lhs, 79 rhs ); 80 } 81 toString()82 public String toString() 83 { 84 return "[(DefaultTruthExpr): " + getLHS() + ", " + getRHS() + "]"; 85 } 86 bothAreSets(Object lhs, Object rhs)87 protected boolean bothAreSets(Object lhs, 88 Object rhs) 89 { 90 return ( lhs instanceof List 91 && 92 rhs instanceof List ); 93 } 94 eitherIsSet(Object lhs, Object rhs)95 protected boolean eitherIsSet(Object lhs, 96 Object rhs) 97 { 98 return ( lhs instanceof List 99 || 100 rhs instanceof List ); 101 } 102 isSet(Object obj)103 protected boolean isSet(Object obj) 104 { 105 return ( obj instanceof List ); 106 } 107 setIsEmpty( List set )108 protected boolean setIsEmpty( List set ) 109 { 110 return (set == null || set.size() == 0); 111 } 112 eitherIsBoolean(Object lhs, Object rhs)113 protected boolean eitherIsBoolean(Object lhs, 114 Object rhs) 115 { 116 return ( lhs instanceof Boolean 117 || 118 rhs instanceof Boolean ); 119 } 120 bothAreBoolean(Object lhs, Object rhs)121 protected boolean bothAreBoolean(Object lhs, 122 Object rhs) 123 { 124 return ( lhs instanceof Boolean 125 && 126 rhs instanceof Boolean ); 127 } 128 eitherIsNumber(Object lhs, Object rhs)129 protected boolean eitherIsNumber(Object lhs, 130 Object rhs) 131 { 132 return ( lhs instanceof Number 133 || 134 rhs instanceof Number ); 135 } 136 isNumber(Object obj)137 protected boolean isNumber(Object obj) 138 { 139 return ( obj instanceof Number ); 140 } 141 isString(Object obj)142 protected boolean isString(Object obj) 143 { 144 return ( obj instanceof String ); 145 } 146 isBoolean(Object obj)147 protected boolean isBoolean(Object obj) 148 { 149 return ( obj instanceof Boolean ); 150 } 151 } 152 153