001/**
002 * Copyright (c) 2011, The University of Southampton and the individual contributors.
003 * All rights reserved.
004 *
005 * Redistribution and use in source and binary forms, with or without modification,
006 * are permitted provided that the following conditions are met:
007 *
008 *   *  Redistributions of source code must retain the above copyright notice,
009 *      this list of conditions and the following disclaimer.
010 *
011 *   *  Redistributions in binary form must reproduce the above copyright notice,
012 *      this list of conditions and the following disclaimer in the documentation
013 *      and/or other materials provided with the distribution.
014 *
015 *   *  Neither the name of the University of Southampton nor the names of its
016 *      contributors may be used to endorse or promote products derived from this
017 *      software without specific prior written permission.
018 *
019 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
020 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
021 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
022 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
023 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
024 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
025 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
026 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
027 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
028 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
029 */
030package org.openimaj.util.iterator;
031
032import java.util.Iterator;
033
034/**
035 * Wrapper to allow an {@link Iterator} as an {@link Iterable} so it can be used
036 * in an a foreach loop. The iterator is consumed by the loop and so must only
037 * be used once. Normal usage is as follows:
038 * 
039 * <pre>
040 * for (T t : IterableIterator.in(iterator)) {
041 *      // ...
042 * }
043 * </pre>
044 * 
045 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
046 * 
047 * @param <T>
048 *            Type of object being iterated over.
049 */
050public class IterableIterator<T> implements Iterable<T> {
051        Iterator<T> iterator;
052
053        private IterableIterator(Iterator<T> iterator) {
054                this.iterator = iterator;
055        }
056
057        @Override
058        public Iterator<T> iterator() {
059                return iterator;
060        }
061
062        /**
063         * Wrapper to allow an {@link Iterator} as an {@link Iterable} so it can be
064         * used in a foreach loop. The iterator is consumed by the loop and so must
065         * only be used once. Normal usage is as follows:
066         * 
067         * <pre>
068         * for (T t : IterableIterator.in(iterator)) {
069         *      // ...
070         * }
071         * </pre>
072         * 
073         * @param <T>
074         *            Type of object being iterated over.
075         * 
076         * @param iterator
077         *            an iterator
078         * @return an iterable wrapper which will traverse the iterator once
079         */
080        public static <T> Iterable<T> in(Iterator<T> iterator) {
081                return new IterableIterator<T>(iterator);
082        }
083}