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: * opTEST is a variation of SEL that optimizes for recursion
33: * in the else part. It eliminates pushing anything on the Dump.
34: * Modifes S register.
35: * @see SECDMachine
36: * @see opSEL
37: * @author Micheal S. Hewett hewett@cs.stanford.edu
38: *
39: */
40: class opTEST extends SECDop {
41: /**
42: * It calls <tt>SECDop()</tt> with the machine argument
43: * and the label of this instruction.
44: * @see SECDMachine
45: */
46: public opTEST(Jatha lisp) {
47: super (lisp, "TEST");
48: }
49:
50: public void Execute(SECDMachine machine) {
51: LispValue selector = machine.S.pop();
52: LispValue trueValue;
53:
54: machine.C.pop(); /* Pop the TEST command. */
55: trueValue = machine.C.pop();
56:
57: if (selector != f_lisp.NIL)
58: machine.C.assign(trueValue);
59: }
60:
61: public LispValue grindef(LispValue code, int indentAmount) {
62: indent(indentAmount);
63:
64: System.out.print(functionName);
65: f_lisp.NEWLINE.internal_princ(System.out);
66:
67: printCode(code.second(), indentAmount + 8);
68: f_lisp.NEWLINE.internal_princ(System.out);
69:
70: return code.cdr().cdr();
71: }
72: }
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