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
20 package net.sf.zel.instr.var;
21
22 import net.sf.zel.instr.*;
23 import net.sf.zel.vm.*;
24 import java.util.LinkedList;
25
26 /**
27 *
28 * @author zoly
29 */
30 public class DECODE extends Instruction
31 {
32 private static final long serialVersionUID = 625079099199504734L;
33
34 private DECODE(){};
35
36 public final void execute(ExecutionContext context)
37 {
38 Object param = null;
39 Object result = null;
40
41 LinkedList params = new LinkedList();
42 while (!((param = context.popSyncStackVal()) == EndParamMarker.instance))
43 {
44 params.addFirst(param);
45 }
46 final Object expr = params.get(0);
47 final int paramsLength = params.size();
48 for (int i = 1; i < paramsLength; i += 2)
49 {
50 param = params.get(i);
51 if (i + 1 >= paramsLength)
52 {
53 result = param;
54 break;
55 } else if (expr.equals(param))
56 {
57 result = params.get(i + 1);
58 break;
59 }
60 }
61 context.stack.push(result);
62 context.ip++;
63 }
64 /**
65 * instance
66 */
67 public static final Instruction instance = new DECODE();
68 }