/**
* =========================================
* 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.]
*
*
* ------------
* ConcatOperator.java
* ------------
*/
package org.pentaho.reporting.libraries.formula.operators;
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.coretypes.TextType;
/**
* Concats two strings operator.
*
* @author Thomas Morgner
*/
public class ConcatOperator implements InfixOperator
{
private static final long serialVersionUID = 6579968694761281257L;
public ConcatOperator()
{
}
public TypeValuePair evaluate(final FormulaContext context,
final TypeValuePair value1,
final TypeValuePair value2)
throws EvaluationException
{
final TypeRegistry typeRegistry = context.getTypeRegistry();
// Error or empty string, that's the question ..
final Object raw1 = value1.getValue();
final Object raw2 = value2.getValue();
if (raw1 == null || raw2 == null)
{
throw new EvaluationException(LibFormulaErrorValue.ERROR_NA_VALUE);
}
final String text1 = typeRegistry.convertToText(value1.getType(), raw1);
final String text2 = typeRegistry.convertToText(value2.getType(), raw2);
if (text1 == null && text2 == null)
{
throw new EvaluationException
(LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE);
}
if (text1 == null)
{
return new TypeValuePair(TextType.TYPE, text2);
}
if (text2 == null)
{
return new TypeValuePair(TextType.TYPE, text1);
}
return new TypeValuePair(TextType.TYPE, text1 + text2);
}
public int getLevel()
{
return 300;
}
public String toString()
{
return "&";
}
public boolean isLeftOperation()
{
return true;
}
/**
* Defines, whether the operation is associative. For associative operations,
* the evaluation order does not matter, if the operation appears more than
* once in an expression, and therefore we can optimize them a lot better than
* non-associative operations (ie. merge constant parts and precompute them
* once).
*
* @return true, if the operation is associative, false otherwise
*/
public boolean isAssociative()
{
return false;
}
}