1 /* 2 * $Header: /cvsroot/jaxen/jaxen/src/java/main/org/jaxen/expr/DefaultRelationalExpr.java,v 1.8 2002/04/26 17:17:34 jstrachan Exp $ 3 * $Revision: 1.8 $ 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: DefaultRelationalExpr.java,v 1.8 2002/04/26 17:17:34 jstrachan Exp $ 60 */ 61 62 63 64 package org.jaxen.expr; 65 66 import java.util.List; 67 import java.util.Iterator; 68 import org.jaxen.Context; 69 import org.jaxen.Navigator; 70 import org.jaxen.JaxenException; 71 import org.jaxen.function.NumberFunction; 72 73 abstract class DefaultRelationalExpr extends DefaultTruthExpr 74 { DefaultRelationalExpr( Expr lhs, Expr rhs )75 public DefaultRelationalExpr( Expr lhs, Expr rhs ) 76 { 77 super( lhs, rhs ); 78 } 79 toString()80 public String toString() 81 { 82 return "[(DefaultRelationalExpr): " + getLHS() + ", " + getRHS() + "]"; 83 } 84 evaluate( Context context )85 public Object evaluate( Context context ) throws JaxenException 86 { 87 Object lhsValue = getLHS().evaluate( context ); 88 Object rhsValue = getRHS().evaluate( context ); 89 Navigator nav = context.getNavigator(); 90 91 if( bothAreSets( lhsValue, rhsValue ) ) 92 { 93 return evaluateSetSet( (List) lhsValue, (List) rhsValue, nav ); 94 } 95 96 if( eitherIsSet( lhsValue, rhsValue ) ) 97 { 98 if( isSet( lhsValue ) ) 99 { 100 return evaluateSetSet( (List) lhsValue, convertToList( rhsValue ), nav ); 101 } 102 else 103 { 104 return evaluateSetSet( convertToList( lhsValue ), (List) rhsValue, nav ); 105 } 106 } 107 108 return evaluateObjectObject( lhsValue, rhsValue, nav ) ? Boolean.TRUE : Boolean.FALSE; 109 } 110 evaluateSetSet( List lhsSet, List rhsSet, Navigator nav )111 private Object evaluateSetSet( List lhsSet, List rhsSet, Navigator nav ) 112 { 113 if( setIsEmpty( lhsSet ) || setIsEmpty( rhsSet ) ) // return false if either is null or empty 114 { 115 return Boolean.FALSE; 116 } 117 118 for( Iterator lhsIterator = lhsSet.iterator(); lhsIterator.hasNext(); ) 119 { 120 Object lhs = lhsIterator.next(); 121 122 for( Iterator rhsIterator = rhsSet.iterator(); rhsIterator.hasNext(); ) 123 { 124 Object rhs = rhsIterator.next(); 125 126 if( evaluateObjectObject( lhs, rhs, nav ) ) 127 { 128 return Boolean.TRUE; 129 } 130 } 131 } 132 133 return Boolean.FALSE; 134 } 135 evaluateObjectObject( Object lhs, Object rhs, Navigator nav )136 private boolean evaluateObjectObject( Object lhs, Object rhs, Navigator nav ) 137 { 138 if( lhs == null || rhs == null ) 139 { 140 return false; 141 } 142 143 Double lhsNum = NumberFunction.evaluate( lhs, nav ); 144 Double rhsNum = NumberFunction.evaluate( rhs, nav ); 145 146 if( NumberFunction.isNaN( lhsNum ) || NumberFunction.isNaN( rhsNum ) ) 147 { 148 return false; 149 } 150 151 return evaluateDoubleDouble( lhsNum, rhsNum ); 152 } 153 evaluateDoubleDouble( Double lhs, Double rhs )154 protected abstract boolean evaluateDoubleDouble( Double lhs, Double rhs ); 155 } 156 157