/**
* =========================================
* 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: ContextLookup.java,v 1.7 2007/04/01 13:51:54 taqua Exp $
* ------------
* (C) Copyright 2006-2007, by Pentaho Corporation.
*/
package org.jfree.formula.lvalues;
import org.jfree.formula.typing.Type;
import org.jfree.formula.FormulaContext;
import org.jfree.formula.EvaluationException;
/**
* A reference that queries the datarow.
*
* @author Thomas Morgner
*/
public class ContextLookup extends AbstractLValue
{
private String name;
public ContextLookup(final String name)
{
this.name = name;
}
public TypeValuePair evaluate() throws EvaluationException
{
final FormulaContext context = getContext();
final Object value = context.resolveReference(name);
final Type type = context.resolveReferenceType(name);
return new TypeValuePair(type, value);
}
public String toString()
{
return "[" + name + "]";
}
/**
* Checks, whether the LValue is constant. Constant lvalues always return the
* same value.
*
* @return
*/
public boolean isConstant()
{
return false;
}
public String getName()
{
return name;
}
}