001 /**
002 * =========================================
003 * LibFormula : a free Java formula library
004 * =========================================
005 *
006 * Project Info: http://reporting.pentaho.org/libformula/
007 *
008 * (C) Copyright 2006-2007, by Pentaho Corporation and Contributors.
009 *
010 * This library is free software; you can redistribute it and/or modify it under the terms
011 * of the GNU Lesser General Public License as published by the Free Software Foundation;
012 * either version 2.1 of the License, or (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
015 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
016 * See the GNU Lesser General Public License for more details.
017 *
018 * You should have received a copy of the GNU Lesser General Public License along with this
019 * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
020 * Boston, MA 02111-1307, USA.
021 *
022 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
023 * in the United States and other countries.]
024 *
025 *
026 * ------------
027 * $Id: AbstractCompareOperator.java 3522 2007-10-16 10:56:57Z tmorgner $
028 * ------------
029 * (C) Copyright 2006-2007, by Pentaho Corporation.
030 */
031
032 package org.jfree.formula.operators;
033
034 import org.jfree.formula.lvalues.TypeValuePair;
035 import org.jfree.formula.FormulaContext;
036 import org.jfree.formula.EvaluationException;
037 import org.jfree.formula.LibFormulaErrorValue;
038 import org.jfree.formula.typing.TypeRegistry;
039 import org.jfree.formula.typing.Type;
040 import org.jfree.formula.typing.ExtendedComparator;
041 import org.jfree.formula.typing.coretypes.LogicalType;
042
043 /**
044 * Creation-Date: 06.06.2007, 18:52:25
045 *
046 * @author Thomas Morgner
047 */
048 public abstract class AbstractCompareOperator implements InfixOperator
049 {
050 private static final TypeValuePair RETURN_TRUE = new TypeValuePair(LogicalType.TYPE, Boolean.TRUE);
051 private static final TypeValuePair RETURN_FALSE = new TypeValuePair(LogicalType.TYPE, Boolean.FALSE);
052
053 public AbstractCompareOperator()
054 {
055 }
056
057 public final TypeValuePair evaluate(final FormulaContext context,
058 final TypeValuePair value1,
059 final TypeValuePair value2)
060 throws EvaluationException
061 {
062 final TypeRegistry typeRegistry = context.getTypeRegistry();
063 final Type type1 = value1.getType();
064 final Type type2 = value2.getType();
065 final Object value1Raw = value1.getValue();
066 final Object value2Raw = value2.getValue();
067 if (value1Raw == null || value2Raw == null)
068 {
069 throw new EvaluationException(LibFormulaErrorValue.ERROR_NA_VALUE);
070 }
071
072 final ExtendedComparator comparator = typeRegistry.getComparator(type1, type2);
073 final Integer result = comparator.compare (type1, value1Raw, type2, value2Raw);
074 if (result == null)
075 {
076 throw new EvaluationException
077 (LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE);
078 }
079
080 if (evaluate(result.intValue()))
081 {
082 return RETURN_TRUE;
083 }
084 return RETURN_FALSE;
085 }
086
087 protected abstract boolean evaluate(int compareResult);
088 }