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: PrefixTerm.java 2780 2007-05-07 22:51:12Z mimil $ 028 * ------------ 029 * (C) Copyright 2006-2007, by Pentaho Corporation. 030 */ 031 package org.jfree.formula.lvalues; 032 033 import org.jfree.formula.operators.PrefixOperator; 034 import org.jfree.formula.EvaluationException; 035 036 /** 037 * Creation-Date: 02.11.2006, 10:20:27 038 * 039 * @author Thomas Morgner 040 */ 041 public class PrefixTerm extends AbstractLValue 042 { 043 private PrefixOperator operator; 044 private LValue value; 045 046 public PrefixTerm(final PrefixOperator operator, final LValue value) 047 { 048 if (operator == null) 049 { 050 throw new NullPointerException(); 051 } 052 if (value == null) 053 { 054 throw new NullPointerException(); 055 } 056 057 this.operator = operator; 058 this.value = value; 059 } 060 061 public PrefixOperator getOperator() 062 { 063 return operator; 064 } 065 066 public LValue getValue() 067 { 068 return value; 069 } 070 071 072 public TypeValuePair evaluate() throws EvaluationException 073 { 074 return operator.evaluate(getContext(), value.evaluate()); 075 } 076 077 078 public String toString() 079 { 080 return "(" + operator + value + ")"; 081 } 082 083 /** 084 * Returns any dependent lvalues (parameters and operands, mostly). 085 * 086 * @return 087 */ 088 public LValue[] getChildValues() 089 { 090 return new LValue[]{ value }; 091 } 092 093 /** 094 * Checks, whether the LValue is constant. Constant lvalues always return the 095 * same value. 096 * 097 * @return 098 */ 099 public boolean isConstant() 100 { 101 return value.isConstant(); 102 } 103 104 public Object clone() throws CloneNotSupportedException 105 { 106 final PrefixTerm o = (PrefixTerm) super.clone(); 107 o.value = (LValue) value.clone(); 108 return o; 109 } 110 }