001package org.conqat.lib.commons.collections;
002
003/**
004 * Offers the ability to perform lookahead on an ordered collection.
005 */
006public interface ILookahead<Data, X extends Exception> {
007
008        /**
009         * Returned elements remain in the underlying data structure and are still
010         * accessible.
011         * 
012         * @param index
013         *            Number of elements that are looked ahead
014         * 
015         * @return Element at index, or null, if the provider doesn't contain that
016         *         many elements anymore
017         */
018        public Data lookahead(int index) throws X;
019}