Source for org.jfree.formula.function.userdefined.NullFunction

   1: /**
   2:  * =========================================
   3:  * LibFormula : a free Java formula library
   4:  * =========================================
   5:  *
   6:  * Project Info:  http://reporting.pentaho.org/libformula/
   7:  *
   8:  * (C) Copyright 2006-2007, by Pentaho Corporation and Contributors.
   9:  *
  10:  * This library is free software; you can redistribute it and/or modify it under the terms
  11:  * of the GNU Lesser General Public License as published by the Free Software Foundation;
  12:  * either version 2.1 of the License, or (at your option) any later version.
  13:  *
  14:  * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
  15:  * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  16:  * See the GNU Lesser General Public License for more details.
  17:  *
  18:  * You should have received a copy of the GNU Lesser General Public License along with this
  19:  * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  20:  * Boston, MA 02111-1307, USA.
  21:  *
  22:  * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
  23:  * in the United States and other countries.]
  24:  *
  25:  *
  26:  * ------------
  27:  * $Id: NullFunction.java,v 1.3 2007/04/01 13:51:53 taqua Exp $
  28:  * ------------
  29:  * (C) Copyright 2006-2007, by Pentaho Corporation.
  30:  */
  31: 
  32: package org.jfree.formula.function.userdefined;
  33: 
  34: import org.jfree.formula.FormulaContext;
  35: import org.jfree.formula.function.ParameterCallback;
  36: import org.jfree.formula.lvalues.TypeValuePair;
  37: import org.jfree.formula.typing.coretypes.AnyType;
  38: 
  39: /**
  40:  * Creation-Date: Dec 18, 2006, 12:54:55 PM
  41:  *
  42:  * @author Thomas Morgner
  43:  */
  44: public class NullFunction
  45: {
  46:   private static final TypeValuePair NULL = new TypeValuePair(AnyType.TYPE, null);
  47: 
  48:   public NullFunction()
  49:   {
  50:   }
  51: 
  52:   public String getCanonicalName()
  53:   {
  54:     return "NULL";
  55:   }
  56: 
  57:   public TypeValuePair evaluate(FormulaContext context,
  58:                                 ParameterCallback parameters)
  59:   {
  60:     return NULL;
  61:   }
  62: 
  63: }