Source for org.jfree.formula.function.information.IsLogicalFunction

   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: IsLogicalFunction.java,v 1.6 2007/05/07 23:00:37 mimil Exp $
  28:  * ------------
  29:  * (C) Copyright 2006-2007, by Pentaho Corporation.
  30:  */
  31: package org.jfree.formula.function.information;
  32: 
  33: import org.jfree.formula.EvaluationException;
  34: import org.jfree.formula.FormulaContext;
  35: import org.jfree.formula.LibFormulaErrorValue;
  36: import org.jfree.formula.function.Function;
  37: import org.jfree.formula.function.ParameterCallback;
  38: import org.jfree.formula.lvalues.TypeValuePair;
  39: import org.jfree.formula.typing.Type;
  40: import org.jfree.formula.typing.coretypes.LogicalType;
  41: 
  42: /**
  43:  * This function checks whatever the given value is of Logical type.
  44:  * 
  45:  * @author Cedric Pronzato
  46:  * 
  47:  */
  48: public class IsLogicalFunction implements Function
  49: {
  50:   private static final TypeValuePair RETURN_TRUE = new TypeValuePair(
  51:       LogicalType.TYPE, Boolean.TRUE);
  52: 
  53:   private static final TypeValuePair RETURN_FALSE = new TypeValuePair(
  54:       LogicalType.TYPE, Boolean.FALSE);
  55: 
  56:   public IsLogicalFunction()
  57:   {
  58:   }
  59: 
  60:   public TypeValuePair evaluate(FormulaContext context,
  61:       ParameterCallback parameters) throws EvaluationException
  62:   {
  63:     final int parameterCount = parameters.getParameterCount();
  64:     if (parameterCount < 1)
  65:     {
  66:       throw new EvaluationException(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE);
  67:     }
  68: 
  69:      final Type type1 = parameters.getType(0);
  70:      final Object value1 = parameters.getValue(0);
  71:      if(value1 instanceof Boolean || type1.isFlagSet(Type.LOGICAL_TYPE))
  72:      {
  73:      return RETURN_TRUE;
  74:      }
  75: 
  76:     // we don't want the auto convertion of paramaters (paramerter.getValue) so
  77:     // we run the evaluate method ourself
  78: //    final TypeValuePair eval = parameters.getRaw(0).evaluate();
  79: //    if (eval.getType().isFlagSet(Type.LOGICAL_TYPE))
  80: //    {
  81: //      return RETURN_TRUE;
  82: //    }
  83: 
  84:     return RETURN_FALSE;
  85:   }
  86: 
  87:   public String getCanonicalName()
  88:   {
  89:     return "ISLOGICAL";
  90:   }
  91: 
  92: }