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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: AbstractLValue.java,v 1.4 2007/04/01 13:51:54 taqua Exp $ 28: * ------------ 29: * (C) Copyright 2006-2007, by Pentaho Corporation. 30: */ 31: package org.jfree.formula.lvalues; 32: 33: import org.jfree.formula.FormulaContext; 34: import org.jfree.formula.EvaluationException; 35: import org.jfree.formula.typing.Type; 36: 37: /** 38: * Creation-Date: 01.11.2006, 18:19:00 39: * 40: * @author Thomas Morgner 41: */ 42: public abstract class AbstractLValue implements LValue 43: { 44: private static LValue[] EMPTY_CHILDS = new LValue[0]; 45: 46: private transient FormulaContext context; 47: 48: protected AbstractLValue() 49: { 50: } 51: 52: public void initialize(FormulaContext context) throws EvaluationException 53: { 54: this.context = context; 55: } 56: 57: public FormulaContext getContext() 58: { 59: if (context == null) throw new NullPointerException(); 60: return context; 61: } 62: 63: public Object clone() throws CloneNotSupportedException 64: { 65: return (AbstractLValue) super.clone(); 66: } 67: 68: /** 69: * Returns any dependent lvalues (parameters and operands, mostly). 70: * 71: * @return 72: */ 73: public LValue[] getChildValues() 74: { 75: return EMPTY_CHILDS; 76: } 77: 78: /** 79: * Querying the value type is only valid *after* the value has been 80: * evaluated. 81: * 82: * @return 83: */ 84: public Type getValueType() 85: { 86: return null; 87: } 88: }