/*
* $Id$
* This file is a part of the Arakhne Foundation Classes, http://www.arakhne.org/afc
*
* Copyright (c) 2000-2012 Stephane GALLAND.
* Copyright (c) 2005-10, Multiagent Team, Laboratoire Systemes et Transports,
* Universite de Technologie de Belfort-Montbeliard.
* Copyright (c) 2013-2016 The original authors, and other authors.
*
* 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.arakhne.afc.sizediterator;
import java.util.Collection;
import java.util.Iterator;
import org.eclipse.xtext.xbase.lib.Pure;
/**
* Sized iterator on a collection that cannot be changed through the iterator.
*
* <p>A sized iterator is an Iterator that is able to
* reply the size of the iterated collection and
* the number of elements that may be encountered
* in the next iterations.
*
* <p>This iterator disables the use of the function {@link #remove()}.
* See {@link ModifiableCollectionSizedIterator} for an sized iterator
* that enables this function.
*
* @param <M> is the type of element.
* @author $Author: sgalland$
* @version $FullVersion$
* @mavengroupid $GroupId$
* @mavenartifactid $ArtifactId$
* @see ModifiableCollectionSizedIterator
*/
public class UnmodifiableCollectionSizedIterator<M> implements SizedIterator<M> {
private final int total;
private int rest;
private final Iterator<M> iterator;
/** Construct an iterator.
*
* @param collection the collection to iterate on.
*/
public UnmodifiableCollectionSizedIterator(Collection<M> collection) {
assert collection != null;
this.total = collection.size();
this.rest = this.total;
this.iterator = collection.iterator();
}
@Pure
@Override
public int rest() {
return this.rest;
}
@Pure
@Override
public int index() {
return this.total - this.rest;
}
@Pure
@Override
public int totalSize() {
return this.total;
}
@Pure
@Override
public boolean hasNext() {
return this.iterator.hasNext();
}
@Override
public M next() {
final M elt = this.iterator.next();
--this.rest;
return elt;
}
}