/**
* =========================================
* 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.]
*
*
* ------------
* MaxFunction.java
* ------------
*/
package org.pentaho.reporting.libraries.formula.function.math;
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.function.Function;
import org.pentaho.reporting.libraries.formula.function.ParameterCallback;
import org.pentaho.reporting.libraries.formula.lvalues.LValue;
import org.pentaho.reporting.libraries.formula.lvalues.TypeValuePair;
import org.pentaho.reporting.libraries.formula.typing.Sequence;
import org.pentaho.reporting.libraries.formula.typing.Type;
import org.pentaho.reporting.libraries.formula.typing.TypeRegistry;
import org.pentaho.reporting.libraries.formula.typing.coretypes.NumberType;
import org.pentaho.reporting.libraries.formula.util.NumberUtil;
/**
* This function returns the maximum from a set of numbers.
*
* @author Cedric Pronzato
*/
public class MaxFunction implements Function
{
private static final BigDecimal ZERO = new BigDecimal(0);
private static final long serialVersionUID = -836670420852371100L;
public MaxFunction()
{
}
public TypeValuePair evaluate(final FormulaContext context,
final ParameterCallback parameters) throws EvaluationException
{
final int parameterCount = parameters.getParameterCount();
if (parameterCount == 0)
{
return new TypeValuePair(NumberType.GENERIC_NUMBER, ZERO);
}
final TypeRegistry typeRegistry = context.getTypeRegistry();
BigDecimal last = null;
for (int paramIdx = 0; paramIdx < parameterCount; paramIdx++)
{
final Type type = parameters.getType(paramIdx);
final Object value = parameters.getValue(paramIdx);
final Sequence sequence = typeRegistry.convertToNumberSequence(type, value, isStrictSequenceNeeded());
while (sequence.hasNext())
{
final LValue rawValue = sequence.nextRawValue();
if (rawValue == null)
{
throw new EvaluationException(LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE);
}
final TypeValuePair nextValue = rawValue.evaluate();
final Number number = typeRegistry.convertToNumber(nextValue.getType(), nextValue.getValue());
final BigDecimal next = NumberUtil.getAsBigDecimal(number);
if (last == null)
{
last = next;
}
else
{
if (last.compareTo(next) == -1)
{
last = next;
}
}
}
}
if (last == null)
{
throw new EvaluationException(LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE);
}
return new TypeValuePair(NumberType.GENERIC_NUMBER, last);
}
protected boolean isStrictSequenceNeeded()
{
return true;
}
public String getCanonicalName()
{
return "MAX";
}
}