001/*
002 * Licensed under the Apache License, Version 2.0 (the "License");
003 * you may not use this file except in compliance with the License.
004 * You may obtain a copy of the License at
005 *
006 *      http://www.apache.org/licenses/LICENSE-2.0
007 *
008 * Unless required by applicable law or agreed to in writing, software
009 * distributed under the License is distributed on an "AS IS" BASIS,
010 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
011 * See the License for the specific language governing permissions and
012 * limitations under the License.
013 */
014
015package org.apache.commons.functor.generator;
016
017import java.util.Collection;
018
019import org.apache.commons.functor.Function;
020import org.apache.commons.functor.generator.util.CollectionTransformer;
021
022/**
023 * Base class for generators. Adds support for all of the Algorithms to
024 * each subclass.
025 *
026 * @param <E> the type of elements held in this generator.
027 * @since 1.0
028 * @version $Revision: 1522355 $ $Date: 2013-09-12 06:29:46 +0200 (Do, 12 Sep 2013) $
029 */
030public abstract class BaseGenerator<E> implements Generator<E> {
031
032    /** Create a new generator. */
033    public BaseGenerator() {
034        super();
035    }
036
037    /**
038     * {@inheritDoc}
039     * Transforms this generator using the passed in
040     * Function. An example function might turn the contents of the
041     * generator into a {@link Collection} of elements.
042     */
043    public final <T> T to(Function<Generator<? extends E>, ? extends T> transformer) {
044        return transformer.evaluate(this);
045    }
046
047    /**
048     * {@inheritDoc}
049     * Same as to(new CollectionTransformer(collection)).
050     */
051    public final <C extends Collection<? super E>> C to(C collection) {
052        return to(new CollectionTransformer<E, C>(collection));
053    }
054
055    /**
056     * {@inheritDoc}
057     * Same as to(new CollectionTransformer()).
058     */
059    public final Collection<E> toCollection() {
060        return to(CollectionTransformer.<E> toCollection());
061    }
062}