/**
* =========================================
* LibFormula : a free Java formula library
* =========================================
*
* Project Info: http://reporting.pentaho.org/libformula/
*
* (C) Copyright 2006-2008, by Pentaho Corporation and Contributors.
*
* This library is free software; you can redistribute it and/or modify it under the terms
* of the GNU Lesser General Public License as published by the Free Software Foundation;
* either version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307, USA.
*
* [Java is a trademark or registered trademark of Sun Microsystems, Inc.
* in the United States and other countries.]
*
*
* ------------
* AbstractNumericOperator.java
* ------------
*/
package org.pentaho.reporting.libraries.formula.operators;
import java.math.BigDecimal;
import org.pentaho.reporting.libraries.formula.EvaluationException;
import org.pentaho.reporting.libraries.formula.FormulaContext;
import org.pentaho.reporting.libraries.formula.LibFormulaErrorValue;
import org.pentaho.reporting.libraries.formula.lvalues.TypeValuePair;
import org.pentaho.reporting.libraries.formula.typing.TypeRegistry;
import org.pentaho.reporting.libraries.formula.typing.Type;
import org.pentaho.reporting.libraries.formula.typing.coretypes.NumberType;
/**
* Creation-Date: 10.04.2007, 15:02:39
*
* @author Thomas Morgner
*/
public abstract class AbstractNumericOperator implements InfixOperator
{
protected static final Number ZERO = new BigDecimal(0);
private static final long serialVersionUID = -1087959445157130705L;
protected AbstractNumericOperator()
{
}
public final TypeValuePair evaluate(final FormulaContext context,
final TypeValuePair value1,
final TypeValuePair value2)
throws EvaluationException
{
final TypeRegistry typeRegistry = context.getTypeRegistry();
if (value1 == null || value2 == null)
{
// If this happens, then one of the implementations has messed up.
throw new EvaluationException(LibFormulaErrorValue.ERROR_UNEXPECTED_VALUE);
}
final Object raw1 = value1.getValue();
final Object raw2 = value2.getValue();
if (raw1 == null || raw2 == null)
{
throw new EvaluationException (LibFormulaErrorValue.ERROR_NA_VALUE);
}
final Number number1 = convertToNumber(typeRegistry, value1.getType(), raw1, ZERO);
final Number number2 = convertToNumber(typeRegistry, value2.getType(), raw2, ZERO);
return new TypeValuePair(NumberType.GENERIC_NUMBER, evaluate(number1, number2));
}
protected abstract Number evaluate (final Number number1, final Number number2) throws EvaluationException;
private static Number convertToNumber (final TypeRegistry registry,
final Type type,
final Object value,
final Number defaultValue)
{
if (value == null)
{
return defaultValue;
}
try
{
return registry.convertToNumber(type, value);
}
catch (EvaluationException e)
{
return defaultValue;
}
}
}