/***********************************************************************************************************************
 *
 * Copyright (C) 2010 by the Stratosphere project (http://stratosphere.eu)
 *
 * 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 eu.stratosphere.pact.common.util;

import java.io.IOException;

/**
 * A simple iterator interface. The key differences to the {@link java.util.Iterator} are that this
 * iterator accepts an object into which it places the content, and that is consolidates the logic
 * in a single <code>next()</code> function, rather than in two different functions such as
 * <code>hasNext()</code> and <code>next()</code>. 
 * 
 * @param <E> The element type of the collection iterated over.
 */
public interface MutableObjectIterator<E> {
	
	/**
	 * Gets the next element from the collection. The contents of that next element is put into the given target object.
	 * 
	 * @param target The target object into which to place next element. 
	 * @return True, if the target object was properly filled with its contents, false if the iterator is exhausted.
	 * 
	 * @throws IOException Thrown, if a problem occurred in the underlying I/O layer or in the 
	 *                     serialization / deserialization logic
	 */
	public boolean next(E target) throws IOException;
}
