/*
* @(#)Iterator.java 1.18 03/01/23
*
* Copyright 2003 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package instrumented.java.util;
/**
* An iterator over a collection. Iterator takes the place of Enumeration in
* the Java collections framework. Iterators differ from enumerations in two
* ways: <ul>
* <li> Iterators allow the caller to remove elements from the
* underlying collection during the iteration with well-defined
* semantics.
* <li> Method names have been improved.
* </ul><p>
*
* This interface is a member of the
* <a href="{@docRoot}/../guide/collections/index.html">
* Java Collections Framework</a>.
*
* @author Josh Bloch
* @version 1.18, 01/23/03
* @see Collection
* @see ListIterator
* @see java.util.Enumeration
* @since 1.2
*/
public interface Iterator {
/**
* Returns <tt>true</tt> if the iteration has more elements. (In other
* words, returns <tt>true</tt> if <tt>next</tt> would return an element
* rather than throwing an exception.)
*
* @return <tt>true</tt> if the iterator has more elements.
*/
boolean hasNext();
/**
* Returns the next element in the iteration.
*
* @return the next element in the iteration.
* @exception NoSuchElementException iteration has no more elements.
*/
Object next();
/**
*
* Removes from the underlying collection the last element returned by the
* iterator (optional operation). This method can be called only once per
* call to <tt>next</tt>. The behavior of an iterator is unspecified if
* the underlying collection is modified while the iteration is in
* progress in any way other than by calling this method.
*
* @exception UnsupportedOperationException if the <tt>remove</tt>
* operation is not supported by this Iterator.
* @exception IllegalStateException if the <tt>next</tt> method has not
* yet been called, or the <tt>remove</tt> method has already
* been called after the last call to the <tt>next</tt>
* method.
*/
void remove();
}