| /******************************************************************************* |
| * Copyright (c) 2015 Oracle. All rights reserved. |
| * This program and the accompanying materials are made available under the |
| * terms of the Eclipse Public License v1.0, which accompanies this distribution |
| * and is available at http://www.eclipse.org/legal/epl-v10.html. |
| * |
| * Contributors: |
| * Oracle - initial API and implementation |
| ******************************************************************************/ |
| package org.eclipse.jpt.common.utility.deque; |
| |
| /** |
| * Interface defining a input-restricted double-ended queue. |
| * Elements can be removed from either end of the queue, |
| * but added to only the tail of the queue. |
| * <p> |
| * Provisional API: This interface is part of an interim API that is still |
| * under development and expected to change significantly before reaching |
| * stability. It is available at this early stage to solicit feedback from |
| * pioneering adopters on the understanding that any code that uses this API |
| * will almost certainly be broken (repeatedly) as the API evolves. |
| * |
| * @param <E> the type of elements contained by the deque |
| * @see Deque |
| */ |
| public interface InputRestrictedDeque<E> { |
| |
| /** |
| * "Enqueue" the specified item to the tail of the deque. |
| */ |
| void enqueueTail(E element); |
| |
| /** |
| * "Dequeue" an item from the head of the deque. |
| */ |
| E dequeueHead(); |
| |
| /** |
| * "Dequeue" an item from the tail of the deque. |
| */ |
| E dequeueTail(); |
| |
| /** |
| * Return the item on the head of the deque |
| * without removing it from the deque. |
| */ |
| E peekHead(); |
| |
| /** |
| * Return the item on the tail of the deque |
| * without removing it from the deque. |
| */ |
| E peekTail(); |
| |
| /** |
| * Return whether the deque is empty. |
| */ |
| boolean isEmpty(); |
| } |