/*
* Copyright 2002-2004 The Apache Software Foundation
*
* 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 org.apache.commons.collections;
import java.util.Comparator;
/**
* Defines a type of <code>Bag</code> that maintains a sorted order among
* its unique representative members.
*
* @since Commons Collections 2.0
* @version $Revision: 155406 $ $Date: 2005-02-26 12:55:26 +0000 (Sat, 26 Feb 2005) $
*
* @author Chuck Burdick
*/
public interface SortedBag extends Bag {
/**
* Returns the comparator associated with this sorted set, or null
* if it uses its elements' natural ordering.
*
* @return the comparator in use, or null if natural ordering
*/
public Comparator comparator();
/**
* Returns the first (lowest) member.
*
* @return the first element in the sorted bag
*/
public Object first();
/**
* Returns the last (highest) member.
*
* @return the last element in the sorted bag
*/
public Object last();
}