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Java > Open Source Codes > org > armedbear > lisp > logtest


1 /*
2  * logtest.java
3  *
4  * Copyright (C) 2003 Peter Graves
5  * $Id: logtest.java,v 1.3 2003/12/13 00:58:51 piso Exp $
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License
9  * as published by the Free Software Foundation; either version 2
10  * of the License, or (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
20  */
21
22 package org.armedbear.lisp;
23
24 import java.math.BigInteger JavaDoc;
25
26 // ### logtest
27 // logtest integer-1 integer-2 => generalized-boolean
28 // (logtest x y) == (not (zerop (logand x y)))
29 public final class logtest extends Primitive2
30 {
31     private logtest()
32     {
33         super("logtest","integer-1 integer-2");
34     }
35
36     public LispObject execute(LispObject first, LispObject second)
37         throws ConditionThrowable
38     {
39         if (first instanceof Fixnum && second instanceof Fixnum) {
40             return (((Fixnum)first).getValue() & ((Fixnum)second).getValue()) == 0 ? NIL : T;
41         } else {
42             BigInteger JavaDoc n1, n2;
43             if (first instanceof Fixnum)
44                 n1 = ((Fixnum)first).getBigInteger();
45             else if (first instanceof Bignum)
46                 n1 = ((Bignum)first).getValue();
47             else
48                 return signal(new TypeError(first, "integer"));
49             if (second instanceof Fixnum)
50                 n2 = ((Fixnum)second).getBigInteger();
51             else if (second instanceof Bignum)
52                 n2 = ((Bignum)second).getValue();
53             else
54                 return signal(new TypeError(second, "integer"));
55             return n1.and(n2).signum() == 0 ? NIL : T;
56         }
57     }
58
59     private static final logtest LOGTEST = new logtest();
60 }
61
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