SIterator.java

/*
 *  This file is part of the Haven & Hearth game client.
 *  Copyright (C) 2009 Fredrik Tolf <fredrik@dolda2000.com>, and
 *                     Björn Johannessen <johannessen.bjorn@gmail.com>
 *
 *  Redistribution and/or modification of this file is subject to the
 *  terms of the GNU Lesser General Public License, version 3, as
 *  published by the Free Software Foundation.
 *
 *  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.
 *
 *  Other parts of this source tree adhere to other copying
 *  rights. Please see the file `COPYING' in the root directory of the
 *  source tree for details.
 *
 *  A copy the GNU Lesser General Public License is distributed along
 *  with the source tree of which this file is a part in the file
 *  `doc/LPGL-3'. If it is missing for any reason, please see the Free
 *  Software Foundation's website at <http://www.fsf.org/>, or write
 *  to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 *  Boston, MA 02111-1307 USA
 */

package haven;

import java.util.*;

public abstract class SIterator<T> implements Iterator<T> {
    private int st = 0;
    private T n;
    
    public abstract T snext() throws NoSuchElementException;

    private void ref() {
	if(st == 0) {
	    try {
		n = snext();
		st = 1;
	    } catch(NoSuchElementException e) {
		st = 2;
	    }
	}
    }

    public boolean hasNext() {
	ref();
	return(st == 1);
    }

    public T next() {
	ref();
	if(st == 2)
	    throw(new NoSuchElementException());
	st = 0;
	return(n);
    }

    public void remove() {
	throw(new UnsupportedOperationException());
    }
}