88 lines
3.4 KiB
Java
88 lines
3.4 KiB
Java
/* Iterator.java -- Interface for iterating over collections
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Copyright (C) 1998, 2001, 2004, 2005 Free Software Foundation, Inc.
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This file is part of GNU Classpath.
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GNU Classpath is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GNU Classpath is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GNU Classpath; see the file COPYING. If not, write to the
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Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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02110-1301 USA.
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Linking this library statically or dynamically with other modules is
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making a combined work based on this library. Thus, the terms and
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conditions of the GNU General Public License cover the whole
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combination.
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As a special exception, the copyright holders of this library give you
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permission to link this library with independent modules to produce an
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executable, regardless of the license terms of these independent
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modules, and to copy and distribute the resulting executable under
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terms of your choice, provided that you also meet, for each linked
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independent module, the terms and conditions of the license of that
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module. An independent module is a module which is not derived from
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or based on this library. If you modify this library, you may extend
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this exception to your version of the library, but you are not
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obligated to do so. If you do not wish to do so, delete this
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exception statement from your version. */
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package java.util;
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/**
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* An object which iterates over a collection. An Iterator is used to return
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* the items once only, in sequence, by successive calls to the next method.
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* It is also possible to remove elements from the underlying collection by
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* using the optional remove method. Iterator is intended as a replacement
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* for the Enumeration interface of previous versions of Java, which did not
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* have the remove method and had less conveniently named methods.
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*
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* @author Original author unknown
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* @author Eric Blake (ebb9@email.byu.edu)
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* @see Collection
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* @see ListIterator
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* @see Enumeration
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* @since 1.2
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* @status updated to 1.4
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*/
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public interface Iterator<E>
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{
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/**
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* Tests whether there are elements remaining in the collection. In other
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* words, calling <code>next()</code> will not throw an exception.
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*
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* @return true if there is at least one more element in the collection
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*/
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boolean hasNext();
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/**
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* Obtain the next element in the collection.
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*
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* @return the next element in the collection
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* @throws NoSuchElementException if there are no more elements
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*/
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E next();
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/**
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* Remove from the underlying collection the last element returned by next
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* (optional operation). This method can be called only once after each
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* call to <code>next()</code>. It does not affect what will be returned
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* by subsequent calls to next.
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*
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* @throws IllegalStateException if next has not yet been called or remove
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* has already been called since the last call to next.
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* @throws UnsupportedOperationException if this Iterator does not support
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* the remove operation.
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*/
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void remove();
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}
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