01: /*
02: * Jatha - a Common LISP-compatible LISP library in Java.
03: * Copyright (C) 1997-2005 Micheal Scott Hewett
04: *
05: * This library is free software; you can redistribute it and/or
06: * modify it under the terms of the GNU Lesser General Public
07: * License as published by the Free Software Foundation; either
08: * version 2.1 of the License, or (at your option) any later version.
09: *
10: * This library is distributed in the hope that it will be useful,
11: * but WITHOUT ANY WARRANTY; without even the implied warranty of
12: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13: * Lesser General Public License for more details.
14: *
15: * You should have received a copy of the GNU Lesser General Public
16: * License along with this library; if not, write to the Free Software
17: * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18: *
19: *
20: * For further information, please contact Micheal Hewett at
21: * hewett@cs.stanford.edu
22: *
23: */
24:
25: package org.jatha.machine;
26:
27: import org.jatha.dynatype.*;
28: import org.jatha.Jatha;
29:
30: // @date Mon Feb 3 19:02:37 1997
31: /**
32: * SECDRegister is essentially a Stack, with
33: * an additional <tt>assign()</tt> method
34: * which resets the value, and a <tt>value()</tt>
35: * method which retrieves the whole stack.
36: *
37: * @author Micheal S. Hewett hewett@cs.stanford.edu
38: */
39: public class SECDRegister extends StandardLispSymbol {
40:
41: public SECDRegister(Jatha lisp, String name) {
42: super (lisp, name);
43: assign(lisp.NIL);
44: }
45:
46: // POP and PUSH are defined by LispSymbol
47:
48: /**
49: * Assign sets the value of a register.
50: *
51: * @param newValue
52: */
53: public void assign(LispValue newValue) {
54: setf_symbol_value(newValue);
55: }
56:
57: /**
58: * Returns the value of a register.
59: *
60: * @return LispValue
61: */
62: public LispValue value() {
63: return symbol_value();
64: }
65:
66: }
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