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Iterator

Kind of class:	public interface
Package:	com.bourre.collection
Inherits from:	none
Implemented by:	ConcretIterator GridIterator ObjectIterator QueueIterator XMLListIterator
Known subinterfaces:	ListIterator
Author:	Francis Bourre
Classpath:	com.bourre.collection.Iterator
File last modified:	Monday, 24 November 2008, 11:36:49

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/*
 * Copyright the original author or authors.
 * 
 * Licensed under the MOZILLA PUBLIC LICENSE, Version 1.1 (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.mozilla.org/MPL/MPL-1.1.html
 * 
 * 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 com.bourre.collection
{
    /**
     * An iterator over a collection.
     * 
     * @author     Francis Bourre
     * @see        Iterable
     */
    public interface Iterator
    {
        /**
         * Returns true if the iteration has more elements.
         * (In other words, returns true if next would return
         * an element rather than throwing an exception.)
         * 
         * @return <code>true</code> if the iterator has more elements.
         */
        function hasNext () : Boolean;
        
         /**
          * Returns the next element in the iteration. Calling this method
          * repeatedly until the hasNext() method returns false will return
          * each element in the underlying collection exactly once.
          * 
          * @return    the next element in the iteration.
          * @throws     <code>NoSuchElementException</code> ‚Äî iteration has no more elements.
          */
         function 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 next. 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.
         * 
         * @throws     <code>UnsupportedOperationException</code> ‚Äî if the remove  operation is not
         *          supported by this Iterator.
         * @throws     <code>IllegalStateException</code> ‚Äî if the next method has not yet been called,
         *          or the remove method has already been called after the last
         *          call to the next  method.
         */
        function remove () : void;
    }
}

An iterator over a collection.

Summary

Instance methods

hasNext : Boolean
- Returns true if the iteration has more elements.
next : *
- Returns the next element in the iteration.
remove : void
- Removes from the underlying collection the last element returned

Instance methods

hasNext

public function hasNext (

) : Boolean

Returns true if the iteration has more elements.
(In other words, returns true if next would return
an element rather than throwing an exception.)

Returns:

true if the iterator has more elements.

public function next (

) : *

Returns the next element in the iteration. Calling this method
repeatedly until the hasNext() method returns false will return
each element in the underlying collection exactly once.

Returns:

the next element in the iteration.

Throws:

{VISDOC_LINK_0}NoSuchElementException — iteration has no more elements.

remove

public function remove (

) : void

Removes from the underlying collection the last element returned
by the iterator (optional operation). This method can be called
only once per call to next. 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.

Throws:

{VISDOC_LINK_0}UnsupportedOperationException — if the remove operation is not
supported by this Iterator.
{VISDOC_LINK_1}IllegalStateException — if the next method has not yet been called,
or the remove method has already been called after the last
call to the next method.