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.compile;
26:
27: import org.jatha.Jatha;
28: import org.jatha.dynatype.*;
29: import org.jatha.machine.*;
30:
31: public class PopPrimitive extends LispPrimitive {
32: public PopPrimitive(Jatha lisp) {
33: super (lisp, "POP", 1);
34: }
35:
36: public void Execute(SECDMachine machine) {
37: machine.S.push(machine.S.pop().pop());
38: machine.C.pop();
39: }
40:
41: public LispValue CompileArgs(LispCompiler compiler,
42: SECDMachine machine, LispValue args, LispValue valueList,
43: LispValue code) {
44: // Don't evaluate the arg. (load it as a constant)
45: return f_lisp.makeCons(machine.LDC, f_lisp.makeCons(args
46: .first(), code));
47: }
48: }
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