/*****************************************************************************
 * Copyright (C) Codehaus.org                                                *
 * ------------------------------------------------------------------------- *
 * Licensed under the Apache License, Version 2.0 (the "License");           *
 * you may not use this file except in compliance with the License.          *
 * You may obtain a copy of the License at                                   *
 *                                                                           *
 * http://www.apache.org/licenses/LICENSE-2.0                                *
 *                                                                           *
 * Unless required by applicable law or agreed to in writing, software       *
 * distributed under the License is distributed on an "AS IS" BASIS,         *
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  *
 * See the License for the specific language governing permissions and       *
 * limitations under the License.                                            *
 *****************************************************************************/
package net.ion.rosetta;

import java.util.ArrayList;
import java.util.List;

import net.ion.rosetta.util.Lists;

/**
 * Common implementations of {@link ListFactory}.
 * 
 * @author Ben Yu
 */
final class ListFactories {

	/** Returns a {@link ListFactory} that creates an empty {@link ArrayList}. */
	@SuppressWarnings("unchecked")
	public static <T> ListFactory<T> arrayListFactory() {
		return ARRAY_LIST_FACTORY;
	}

	/**
	 * Returns a {@link ListFactory} that creates an {@link ArrayList} instance with {@code first} as the first element.
	 */
	public static <T> ListFactory<T> arrayListFactoryWithFirstElement(final T first) {
		return new ListFactory<T>() {
			public List<T> newList() {
				ArrayList<T> list = Lists.arrayList();
				list.add(first);
				return list;
			}
		};
	}

	@SuppressWarnings("unchecked")
	private static final ListFactory ARRAY_LIST_FACTORY = new ListFactory<Object>() {
		public List<Object> newList() {
			return Lists.arrayList();
		}
	};
}