001 /** 002 * ========================================= 003 * LibFormula : a free Java formula library 004 * ========================================= 005 * 006 * Project Info: http://reporting.pentaho.org/libformula/ 007 * 008 * (C) Copyright 2006-2007, by Pentaho Corporation and Contributors. 009 * 010 * This library is free software; you can redistribute it and/or modify it under the terms 011 * of the GNU Lesser General Public License as published by the Free Software Foundation; 012 * either version 2.1 of the License, or (at your option) any later version. 013 * 014 * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; 015 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 016 * See the GNU Lesser General Public License for more details. 017 * 018 * You should have received a copy of the GNU Lesser General Public License along with this 019 * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, 020 * Boston, MA 02111-1307, USA. 021 * 022 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 023 * in the United States and other countries.] 024 * 025 * 026 * ------------ 027 * $Id: IsNumberFunction.java 3521 2007-10-16 10:55:14Z tmorgner $ 028 * ------------ 029 * (C) Copyright 2006-2007, by Pentaho Corporation. 030 */ 031 package org.jfree.formula.function.information; 032 033 import org.jfree.formula.EvaluationException; 034 import org.jfree.formula.FormulaContext; 035 import org.jfree.formula.LibFormulaErrorValue; 036 import org.jfree.formula.function.Function; 037 import org.jfree.formula.function.ParameterCallback; 038 import org.jfree.formula.lvalues.TypeValuePair; 039 import org.jfree.formula.typing.Type; 040 import org.jfree.formula.typing.coretypes.LogicalType; 041 042 /** 043 * This function retruns true if the given value is of type Number. 044 * 045 * @author Cedric Pronzato 046 * 047 */ 048 public class IsNumberFunction implements Function 049 { 050 private static final TypeValuePair RETURN_TRUE = new TypeValuePair(LogicalType.TYPE, Boolean.TRUE); 051 private static final TypeValuePair RETURN_FALSE = new TypeValuePair(LogicalType.TYPE, Boolean.FALSE); 052 053 public IsNumberFunction() 054 { 055 } 056 057 public TypeValuePair evaluate(final FormulaContext context, final ParameterCallback parameters) throws EvaluationException 058 { 059 final int parameterCount = parameters.getParameterCount(); 060 if (parameterCount < 1) 061 { 062 throw new EvaluationException(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE); 063 } 064 065 final Type type1 = parameters.getType(0); 066 if(type1.isFlagSet(Type.NUMERIC_TYPE)) 067 { 068 return RETURN_TRUE; 069 } 070 071 return RETURN_FALSE; 072 } 073 074 public String getCanonicalName() 075 { 076 return "ISNUMBER"; 077 } 078 079 }