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.Jatha;
28: import org.jatha.dynatype.LispValue;
29:
30: // @date Sat Feb 1 22:18:53 1997
31: /**
32: * opLDF prepares to execute a non-recursive function.
33: * It makes a closure and pushes it on the S register.
34: * Uses S register (2 values).
35: * Modifes C, D, E, and S registers.
36: * @see SECDMachine
37: * @author Micheal S. Hewett hewett@cs.stanford.edu
38: */
39: class opLDF extends SECDop {
40: /**
41: * It calls <tt>SECDop()</tt> with the machine argument
42: * and the label of this instruction.
43: * @see SECDMachine
44: */
45: //@author Micheal S. Hewett hewett@cs.stanford.edu
46: public opLDF(Jatha lisp) {
47: super (lisp, "LDF");
48: }
49:
50: public void Execute(SECDMachine machine) {
51: /* Make a closure and push it on the S Register. */
52: machine.C.pop(); // Get rid of 'LDF'
53: LispValue code = machine.C.pop(); // Get the new code.
54:
55: // todo: should we copy the value of E here? My notes in book say to.
56: //
57: machine.S.assign(f_lisp.makeCons(f_lisp.makeCons(code,
58: machine.E.value()), machine.S.value()));
59: // machine.S.push(f_lisp.makeCons(code, machine.E.value()));
60: }
61:
62: public LispValue grindef(LispValue code, int indentAmount) {
63: indent(indentAmount);
64:
65: System.out.print(functionName);
66: f_lisp.NEWLINE.internal_princ(System.out);
67:
68: printCode(code.second(), indentAmount + 8);
69: f_lisp.NEWLINE.internal_princ(System.out);
70:
71: return code.cdr().cdr();
72: }
73: }
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