/*
* logcount.java
*
* Copyright (C) 2003 Peter Graves
* $Id: logcount.java,v 1.6 2003/11/15 11:03:32 beedlem Exp $
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
package org.armedbear.lisp;
import java.math.BigInteger;
// ### logcount
// logcount integer => number-of-on-bits
public final class logcount extends Primitive1
{
private logcount()
{
super("logcount");
}
// FIXME Optimize fixnum case!
public LispObject execute(LispObject arg) throws ConditionThrowable
{
BigInteger n;
if (arg instanceof Fixnum)
n = ((Fixnum)arg).getBigInteger();
else if (arg instanceof Bignum)
n = ((Bignum)arg).getValue();
else
throw new ConditionThrowable(new TypeError(arg, "integer"));
return new Fixnum(n.bitCount());
}
private static final logcount LOGCOUNT = new logcount();
}