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/*
* Copyright (c) 2003 - 2007 Israfil Consulting Services Corporation
* Copyright (c) 2003 - 2007 Christian Edward Gruber
* All Rights Reserved
*
* This software is licensed under the Berkeley Standard Distribution license,
* (BSD license), as defined below:
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. Neither the name of Israfil Consulting Services nor the names of its contributors
* may be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
* OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
* OF SUCH DAMAGE.
*
* $Id: ArraySet.java 76 2006-08-03 15:37:05Z cgruber $
*/
package net.israfil.foundation.collections;
import java.util.AbstractSet;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
/**
* An ArrayList backed Set implementation, whose primary purpose is
* to provide a Set that maintains the order of elements based on
* indexes and/or the order in which items are added. Most
* particularly it's to guarrantee deterministic results of an
* iterator, where the iterator provides each element in the order
* of the underlying list.
*
* Unlike a LinkedHashSet, this implementation leaves a duplicate
* element in its original position. It's performance characteristics
* on input are similar, since a comparison still has to happen
* for de-dupliation, but obtaining the item by index is constant time.
*
* TODO: Consider making this a SortedSet, using the list order as the guarrantee. Not sure if it's a legit use of the API.
* @See java.util.LinkedHashSet
* @author <a href="mailto:cgruber@israfil.net">Christian Edward Gruber </a>
*/
public class ArraySet<E> extends AbstractSet<E> {
private transient ArrayList<E> internalList;
public ArraySet() {
internalList = new ArrayList<E>();
}
public ArraySet(int initialCapacity) {
internalList = new ArrayList<E>(initialCapacity);
}
public ArraySet(Collection<E> col) {
internalList = new ArrayList<E>(col);
Iterator<E> i = col.iterator();
while (i.hasNext()) {
internalList.add(i.next());
}
}
@Override
public Iterator<E> iterator() {
return internalList.iterator();
}
@Override
public int size() {
return internalList.size();
}
@Override
public boolean add(E o) {
if (internalList.contains(o)) return false;
else {
internalList.add(o);
return true;
}
}
@Override
public boolean remove(Object o) {
return internalList.remove(o);
}
public E get(Integer index) {
return internalList.get(index);
}
}
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