View Javadoc

1   /*
2    * Copyright (c) 2001, Zoltan Farkas All Rights Reserved.
3    *
4    * This library is free software; you can redistribute it and/or
5    * modify it under the terms of the GNU Lesser General Public
6    * License as published by the Free Software Foundation; either
7    * version 2.1 of the License, or (at your option) any later version.
8    *
9    * This library is distributed in the hope that it will be useful,
10   * but WITHOUT ANY WARRANTY; without even the implied warranty of
11   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12   * GNU General Public License for more details.
13   *
14   * You should have received a copy of the GNU Lesser General Public
15   * License along with this program; if not, write to the Free Software
16   * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
17   */
18  
19  package net.sf.zel.instr;
20  
21  import net.sf.zel.nr.Operable;
22  import net.sf.zel.vm.*;
23  
24  
25  public final class MUL extends Instruction
26  {
27      private static final long serialVersionUID = -872688683600090372L;
28  
29      private MUL(){};
30  
31      /**
32       * if any of the operands are null the result is null
33       *
34       * @param context
35       * @throws ZExecutionException
36       */
37  
38      public void execute(ExecutionContext context)  throws ZExecutionException
39      {
40              final Operable val1 =  (Operable) context.popSyncStackVal();
41              final Operable val2 =  (Operable) context.popSyncStackVal();
42              if (val1 != null && val2 != null)                
43                  context.stack.push(val1.multiply(val2));
44              else
45                  context.stack.push(null);
46              
47              context.ip++;
48      }
49      /**
50       * instance
51       */    
52      public static final Instruction instance = new MUL();
53  }