Source for org.jfree.formula.lvalues.PostfixTerm

   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: PostfixTerm.java,v 1.5 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.EvaluationException;
  34: import org.jfree.formula.operators.PostfixOperator;
  35: 
  36: /**
  37:  * Creation-Date: 02.11.2006, 10:20:27
  38:  *
  39:  * @author Thomas Morgner
  40:  */
  41: public class PostfixTerm extends AbstractLValue
  42: {
  43:   private PostfixOperator operator;
  44:   private LValue value;
  45: 
  46:   public PostfixTerm(final LValue value, final PostfixOperator operator)
  47:   {
  48:     if (operator == null)
  49:     {
  50:       throw new NullPointerException();
  51:     }
  52:     if (value == null)
  53:     {
  54:       throw new NullPointerException();
  55:     }
  56:     this.operator = operator;
  57:     this.value = value;
  58:   }
  59: 
  60:   public PostfixOperator getOperator()
  61:   {
  62:     return operator;
  63:   }
  64: 
  65:   public LValue getValue()
  66:   {
  67:     return value;
  68:   }
  69: 
  70:   public TypeValuePair evaluate() throws EvaluationException
  71:   {
  72:     return operator.evaluate(getContext(), value.evaluate());
  73:   }
  74: 
  75: 
  76:   public String toString()
  77:   {
  78:     return "(" + value + operator + ')';
  79:   }
  80: 
  81:   /**
  82:    * Checks, whether the LValue is constant. Constant lvalues always return the
  83:    * same value.
  84:    *
  85:    * @return
  86:    */
  87:   public boolean isConstant()
  88:   {
  89:     return value.isConstant();
  90:   }
  91: 
  92:   /**
  93:    * Returns any dependent lvalues (parameters and operands, mostly).
  94:    *
  95:    * @return
  96:    */
  97:   public LValue[] getChildValues()
  98:   {
  99:     return new LValue[]{ value };
 100:   }
 101: 
 102:   public Object clone() throws CloneNotSupportedException
 103:   {
 104:     final PostfixTerm o = (PostfixTerm) super.clone();
 105:     o.value = (LValue) value.clone();
 106:     return o;
 107:   }
 108: }