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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: IsRefFunction.java,v 1.1 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.ContextLookup; 39: import org.jfree.formula.lvalues.LValue; 40: import org.jfree.formula.lvalues.TypeValuePair; 41: import org.jfree.formula.typing.coretypes.LogicalType; 42: 43: /** 44: * This function retruns true if the given value is reference. 45: * 46: * @author Cedric Pronzato 47: * 48: */ 49: public class IsRefFunction implements Function 50: { 51: private static final TypeValuePair RETURN_TRUE = new TypeValuePair( 52: LogicalType.TYPE, Boolean.TRUE); 53: 54: private static final TypeValuePair RETURN_FALSE = new TypeValuePair( 55: LogicalType.TYPE, Boolean.FALSE); 56: 57: public IsRefFunction() 58: { 59: } 60: 61: public TypeValuePair evaluate(FormulaContext context, 62: ParameterCallback parameters) throws EvaluationException 63: { 64: final int parameterCount = parameters.getParameterCount(); 65: if (parameterCount < 1) 66: { 67: throw new EvaluationException(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE); 68: } 69: 70: // we want error values propagated so we need to evaluate the parameter 71: parameters.getValue(0); 72: 73: final LValue raw = parameters.getRaw(0); 74: if (raw instanceof ContextLookup) 75: { 76: return RETURN_TRUE; 77: } 78: 79: return RETURN_FALSE; 80: } 81: 82: public String getCanonicalName() 83: { 84: return "ISREF"; 85: } 86: 87: }