001/*
002 *                    BioJava development code
003 *
004 * This code may be freely distributed and modified under the
005 * terms of the GNU Lesser General Public Licence.  This should
006 * be distributed with the code.  If you do not have a copy,
007 * see:
008 *
009 *      http://www.gnu.org/copyleft/lesser.html
010 *
011 * Copyright for this code is held jointly by the individual
012 * authors.  These should be listed in @author doc comments.
013 *
014 * For more information on the BioJava project and its aims,
015 * or to join the biojava-l mailing list, visit the home page
016 * at:
017 *
018 *      http://www.biojava.org/
019 *
020 */
021
022package org.biojava.bio.seq;
023
024import java.util.NoSuchElementException;
025
026import org.biojava.bio.BioException;
027
028/**
029 * An iterator over a bag of sequences.
030 * <p>
031 * java.util.Iterator was not appropriate here, as we need specific exceptions
032 * to be thrown, and as much type-safety as possible. However, we have made it
033 * as compliant with Iterator as we could so that there is a minimal learning
034 * curve.
035 * @see org.biojavax.bio.seq.RichSequenceIterator
036 * @author Matthew Pocock
037 */
038public interface SequenceIterator {
039  /**
040   * Returns whether there are more sequences to iterate over.
041   *
042   * @return  true if there are more sequences to get and false otherwise
043   */
044  boolean hasNext();
045  
046  /**
047   * Returns the next sequence in the iterator.
048   *
049   * @return the next Sequence
050   * @throws NoSuchElementException if you call nextSequence when hasNext
051   *                                returns false
052   * @throws BioException if for any reason the sequence could not be retrieved
053   */
054  Sequence nextSequence() throws NoSuchElementException, BioException;
055}