source: trunk/abcl/src/org/armedbear/lisp/logbitp.java @ 12642

Last change on this file since 12642 was 12288, checked in by vvoutilainen, 15 years ago

Don't extend Lisp in LispObject, static import Lisp wherever
necessary. Patch by Douglas R. Miles.

  • Property svn:eol-style set to native
  • Property svn:keywords set to Id
File size: 2.8 KB
Line 
1/*
2 * logbitp.java
3 *
4 * Copyright (C) 2003-2005 Peter Graves
5 * $Id: logbitp.java 12288 2009-11-29 22:00:12Z vvoutilainen $
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 * As a special exception, the copyright holders of this library give you
22 * permission to link this library with independent modules to produce an
23 * executable, regardless of the license terms of these independent
24 * modules, and to copy and distribute the resulting executable under
25 * terms of your choice, provided that you also meet, for each linked
26 * independent module, the terms and conditions of the license of that
27 * module.  An independent module is a module which is not derived from
28 * or based on this library.  If you modify this library, you may extend
29 * this exception to your version of the library, but you are not
30 * obligated to do so.  If you do not wish to do so, delete this
31 * exception statement from your version.
32 */
33
34package org.armedbear.lisp;
35
36import static org.armedbear.lisp.Lisp.*;
37
38import java.math.BigInteger;
39
40// ### logbitp index integer => generalized-boolean
41public final class logbitp extends Primitive
42{
43    private logbitp()
44    {
45        super("logbitp", "index integer");
46    }
47
48    @Override
49    public LispObject execute(LispObject first, LispObject second)
50
51    {
52        int index = -1;
53        if (first instanceof Fixnum) {
54            index = ((Fixnum)first).value;
55        } else if (first instanceof Bignum) {
56            // FIXME If the number is really big, we're not checking the right
57            // bit...
58            if (((Bignum)first).value.signum() > 0)
59                index = Integer.MAX_VALUE;
60        }
61        if (index < 0)
62            return type_error(first, Symbol.UNSIGNED_BYTE);
63        BigInteger n;
64        if (second instanceof Fixnum)
65            n = ((Fixnum)second).getBigInteger();
66        else if (second instanceof Bignum)
67            n = ((Bignum)second).value;
68        else
69            return type_error(second, Symbol.INTEGER);
70        // FIXME See above.
71        if (index == Integer.MAX_VALUE)
72            return n.signum() < 0 ? T : NIL;
73        return n.testBit(index) ? T : NIL;
74    }
75
76    private static final Primitive LOGBITP = new logbitp();
77}
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