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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: SubtractOperator.java 2752 2007-04-10 14:10:41Z taqua $ 28: * ------------ 29: * (C) Copyright 2006-2007, by Pentaho Corporation. 30: */ 31: package org.jfree.formula.operators; 32: 33: import java.math.BigDecimal; 34: 35: import org.jfree.formula.EvaluationException; 36: 37: /** 38: * Creation-Date: 31.10.2006, 16:34:11 39: * 40: * @author Thomas Morgner 41: */ 42: public class SubtractOperator extends AbstractNumericOperator 43: { 44: public SubtractOperator() 45: { 46: } 47: 48: protected Number evaluate(final Number number1, final Number number2) throws EvaluationException 49: { 50: if ((number1 instanceof Integer || number1 instanceof Short) && 51: (number2 instanceof Integer || number2 instanceof Short)) 52: { 53: return new BigDecimal (number1.longValue() - number2.longValue()); 54: } 55: 56: final BigDecimal bd1 = new BigDecimal(number1.toString()); 57: final BigDecimal bd2 = new BigDecimal(number2.toString()); 58: return bd1.subtract(bd2); 59: } 60: 61: public int getLevel() 62: { 63: return 200; 64: } 65: 66: public String toString() 67: { 68: return "-"; 69: } 70: 71: public boolean isLeftOperation() 72: { 73: return true; 74: } 75: 76: /** 77: * Defines, whether the operation is associative. For associative operations, 78: * the evaluation order does not matter, if the operation appears more than 79: * once in an expression, and therefore we can optimize them a lot better than 80: * non-associative operations (ie. merge constant parts and precompute them 81: * once). 82: * 83: * @return true, if the operation is associative, false otherwise 84: */ 85: public boolean isAssociative() 86: { 87: return false; 88: } 89: 90: }