/**
* =========================================
* LibFormula : a free Java formula library
* =========================================
*
* Project Info: http://reporting.pentaho.org/libformula/
*
* (C) Copyright 2006-2007, 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.]
*
*
* ------------
* $Id: SumFunction.java,v 1.10 2007/05/07 23:00:37 mimil Exp $
* ------------
* (C) Copyright 2006-2007, by Pentaho Corporation.
*/
package org.jfree.formula.function.math;
import java.math.BigDecimal;
import org.jfree.formula.EvaluationException;
import org.jfree.formula.FormulaContext;
import org.jfree.formula.LibFormulaErrorValue;
import org.jfree.formula.function.Function;
import org.jfree.formula.function.ParameterCallback;
import org.jfree.formula.lvalues.TypeValuePair;
import org.jfree.formula.typing.Type;
import org.jfree.formula.typing.TypeConversionException;
import org.jfree.formula.typing.coretypes.NumberType;
/**
* Creation-Date: 31.10.2006, 17:39:19
*
* @author Thomas Morgner
*/
public class SumFunction implements Function
{
public static final BigDecimal ZERO = new BigDecimal(0);
public SumFunction()
{
}
public String getCanonicalName()
{
return "SUM";
}
public TypeValuePair evaluate(final FormulaContext context,
final ParameterCallback parameters)
throws EvaluationException
{
BigDecimal computedResult = ZERO;
final int parameterCount = parameters.getParameterCount();
if(parameterCount == 0)
{
throw new EvaluationException(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE);
}
for (int paramIdx = 0; paramIdx < parameterCount; paramIdx++)
{
final Object value = parameters.getValue(paramIdx);
final Type type = parameters.getType(paramIdx);
if (value == null)
{
continue;
}
try
{
final Number n = context.getTypeRegistry().convertToNumber(type, value);
computedResult = compute(n, computedResult);
}
catch(TypeConversionException tce)
{
// The sum function ignores invalid values ..
}
}
// TODO: Array not yet supported
/*final Type type = parameters.getType(paramIdx);
if (type.isFlagSet(Type.ARRAY_TYPE) == false)
{
continue;
}
if (type.isFlagSet(Type.NUMERIC_TYPE) == false)
{
continue;
}
final Object[] values = (Object[]) value;
for (int arrayIdx = 0; arrayIdx < values.length; arrayIdx++)
{
computedResult = compute(values[arrayIdx], computedResult);
}
}*/
return new TypeValuePair(NumberType.GENERIC_NUMBER, computedResult);
}
private BigDecimal compute(final Object value,
final BigDecimal computedResult)
{
if (value == null)
{
// no-op ..
return computedResult;
}
if (value instanceof Number == false)
{
// Paranoid checks can be disabled later ..
throw new IllegalArgumentException(String.valueOf(value));
}
if (value instanceof BigDecimal)
{
return computedResult.add((BigDecimal) value);
}
else
{
final Number n = (Number) value;
final BigDecimal nval = new BigDecimal(n.toString());
return computedResult.add(nval);
}
}
}