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 DefconstantPrimitive extends LispPrimitive {
32: public DefconstantPrimitive(Jatha lisp) {
33: super (lisp, "DEFCONSTANT", 2, 3); // symbol, value, documentation
34: }
35:
36: public void Execute(SECDMachine machine) {
37: LispValue val = machine.S.pop();
38: LispValue sym = machine.S.pop();
39:
40: // Assign the value.
41: if (sym.boundp() == f_lisp.T) {
42: System.err.println("Warning: Constant " + sym
43: + " being redefined from " + sym.symbol_value()
44: + " to " + val);
45: }
46: sym.setf_symbol_value(val);
47:
48: // Make it a constant
49: LispValue newSymbol = new StandardLispConstant(f_lisp, sym);
50: f_lisp.SYMTAB.replace((LispString) (sym.symbol_name()),
51: newSymbol);
52:
53: // Declare the symbol as Special
54: newSymbol.set_special(true);
55:
56: // Return the symbol
57: machine.S.push(sym);
58:
59: machine.C.pop(); // Pop the DEFCONSTANT
60: }
61:
62: public LispValue CompileArgs(LispCompiler compiler,
63: SECDMachine machine, LispValue args, LispValue valueList,
64: LispValue code) throws CompilerException {
65: // Don't evaluate the first arg. (load it as a constant)
66: return f_lisp.makeCons(machine.LDC, f_lisp.makeCons(args
67: .first(), compiler.compile(args.second(), valueList,
68: code)));
69: }
70: }
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