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: AbstractNumericOperator.java 2887 2007-06-06 17:07:52Z taqua $
028 * ------------
029 * (C) Copyright 2006-2007, by Pentaho Corporation.
030 */
031
032 package org.jfree.formula.operators;
033
034 import org.jfree.formula.EvaluationException;
035 import org.jfree.formula.FormulaContext;
036 import org.jfree.formula.LibFormulaErrorValue;
037 import org.jfree.formula.lvalues.TypeValuePair;
038 import org.jfree.formula.typing.TypeRegistry;
039 import org.jfree.formula.typing.TypeRegistryUtility;
040 import org.jfree.formula.typing.coretypes.NumberType;
041
042 /**
043 * Creation-Date: 10.04.2007, 15:02:39
044 *
045 * @author Thomas Morgner
046 */
047 public abstract class AbstractNumericOperator implements InfixOperator
048 {
049 protected static final Number ZERO = new Integer(0);
050
051 protected AbstractNumericOperator()
052 {
053 }
054
055 public final TypeValuePair evaluate(final FormulaContext context,
056 final TypeValuePair value1,
057 final TypeValuePair value2)
058 throws EvaluationException
059 {
060 final TypeRegistry typeRegistry = context.getTypeRegistry();
061
062 if (value1 == null || value2 == null)
063 {
064 // If this happens, then one of the implementations has messed up.
065 throw new EvaluationException(LibFormulaErrorValue.ERROR_UNEXPECTED_VALUE);
066 }
067
068 final Object raw1 = value1.getValue();
069 final Object raw2 = value2.getValue();
070 if (raw1 == null || raw2 == null)
071 {
072 throw new EvaluationException (LibFormulaErrorValue.ERROR_NA_VALUE);
073 }
074
075 final Number number1 = TypeRegistryUtility.convertToNumber(typeRegistry, value1.getType(), raw1, ZERO);
076 final Number number2 = TypeRegistryUtility.convertToNumber(typeRegistry, value2.getType(), raw2, ZERO);
077 return new TypeValuePair(NumberType.GENERIC_NUMBER, evaluate(number1, number2));
078 }
079
080 protected abstract Number evaluate (final Number number1, final Number number2) throws EvaluationException;
081 }