RewindableSeqIterator.java

/*
 * Vitry, copyright (C) Hans Hoglund 2011
 * 
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 *
 * See COPYING.txt for details.
 */
package vitry.runtime.struct;


/**
 * A SequenceIterator that remembers its starting point.
 */
public class RewindableSeqIterator<T> extends SeqIterator<T>
{
    private final Seq<T> start;

    public RewindableSeqIterator(Seq<T> seq) {
        super(seq);
        this.start = seq;
    }

    public RewindableSeqIterator(SeqIterator<T> it) {
        super(it.seq);
        this.start = it.seq;
    }

    public void rewind()
    {
        this.seq = start;
    }

//    /**
//     * Returns  all elements leeding up to the current sequence
//     * from the starting point.
//     */
//    public Seq<T> preceding()
//    {
//        return Seqs.until(start, seq);
//    }
}