| /******************************************************************************* |
| * Copyright (c) 2006, 2018 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v2.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v20.html |
| * |
| * Contributors: |
| * IBM - Initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.ocl.examples.eventmanager.util; |
| |
| import java.util.Collection; |
| |
| /** |
| * A bag is a read-only collection that is non-unique and unordered. It is, |
| * therefore, like a set except that any element may occur multiple times. All |
| * modifying operations will throw an {@link UnsupportedOperationException}.<p> |
| * |
| * Note, that no specific {@link Object#equals(Object)} or {@link Object#hashCode()} |
| * requirements are added by this interface. This means that implementations may |
| * simply use the {@link Object}-provided, identity-based comparison semantics. |
| * |
| * @author Christian W. Damus (cdamus), Axel Uhl |
| */ |
| public interface Bag<E> extends Collection<E> { |
| /** |
| * Queries how many times the specified object occurs in me. |
| * If I do not contain the object, then the count is zero. |
| * |
| * @param o an object |
| * @return the number of times that it occurs in me |
| */ |
| int count(Object o); |
| } |
