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1: /** 2: * ========================================= 3: * LibFormula : a free Java formula library 4: * ========================================= 5: * 6: * Project Info: http://reporting.pentaho.org/libformula/ 7: * 8: * (C) Copyright 2006-2007, by Pentaho Corporation and Contributors. 9: * 10: * This library is free software; you can redistribute it and/or modify it under the terms 11: * of the GNU Lesser General Public License as published by the Free Software Foundation; 12: * either version 2.1 of the License, or (at your option) any later version. 13: * 14: * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; 15: * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 16: * See the GNU Lesser General Public License for more details. 17: * 18: * You should have received a copy of the GNU Lesser General Public License along with this 19: * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, 20: * Boston, MA 02111-1307, USA. 21: * 22: * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 23: * in the United States and other countries.] 24: * 25: * 26: * ------------ 27: * $Id: EqualOperator.java,v 1.7 2007/06/06 17:07:52 taqua Exp $ 28: * ------------ 29: * (C) Copyright 2006-2007, by Pentaho Corporation. 30: */ 31: package org.jfree.formula.operators; 32: 33: import org.jfree.formula.EvaluationException; 34: import org.jfree.formula.FormulaContext; 35: import org.jfree.formula.LibFormulaErrorValue; 36: import org.jfree.formula.typing.ExtendedComparator; 37: import org.jfree.formula.typing.TypeRegistry; 38: import org.jfree.formula.typing.Type; 39: import org.jfree.formula.typing.coretypes.LogicalType; 40: import org.jfree.formula.lvalues.TypeValuePair; 41: 42: /** 43: * Creation-Date: 31.10.2006, 16:34:11 44: * 45: * @author Thomas Morgner 46: */ 47: public class EqualOperator implements InfixOperator 48: { 49: private static final TypeValuePair RETURN_TRUE = new TypeValuePair(LogicalType.TYPE, Boolean.TRUE); 50: private static final TypeValuePair RETURN_FALSE = new TypeValuePair(LogicalType.TYPE, Boolean.FALSE); 51: 52: public EqualOperator() 53: { 54: } 55: 56: public TypeValuePair evaluate(final FormulaContext context, 57: final TypeValuePair value1, 58: final TypeValuePair value2) 59: throws EvaluationException 60: { 61: final TypeRegistry typeRegistry = context.getTypeRegistry(); 62: final Object value1Raw = value1.getValue(); 63: final Object value2Raw = value2.getValue(); 64: if (value1Raw == null || value2Raw == null) 65: { 66: throw new EvaluationException(LibFormulaErrorValue.ERROR_NA_VALUE); 67: } 68: 69: final Type type1 = value1.getType(); 70: final Type type2 = value2.getType(); 71: final ExtendedComparator comparator = typeRegistry.getComparator(type1, type2); 72: final boolean result = comparator.isEqual (type1, value1Raw, type2, value2Raw); 73: if (result) 74: { 75: return RETURN_TRUE; 76: } 77: else 78: { 79: return RETURN_FALSE; 80: } 81: } 82: 83: public int getLevel() 84: { 85: return 400; 86: } 87: 88: 89: public String toString() 90: { 91: return "="; 92: } 93: 94: public boolean isLeftOperation() 95: { 96: return true; 97: } 98: 99: /** 100: * Defines, whether the operation is associative. For associative operations, 101: * the evaluation order does not matter, if the operation appears more than 102: * once in an expression, and therefore we can optimize them a lot better than 103: * non-associative operations (ie. merge constant parts and precompute them 104: * once). 105: * 106: * @return true, if the operation is associative, false otherwise 107: */ 108: public boolean isAssociative() 109: { 110: return false; 111: } 112: 113: }