/*
* Copyright (c) 2008, Harald Kuhr
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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.
* * Neither the name "TwelveMonkeys" 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.
*/
package com.twelvemonkeys.util;
import java.util.*;
import java.io.Serializable;
/**
* Generic map and linked list implementation of the {@code Set} interface,
* with predictable iteration order.
* <p>
* Resembles {@code LinkedHashSet} from JDK 1.4+, but is backed by a generic
* {@code LinkedMap}, rather than implementing a particular algoritm.
* <p/>
* @see LinkedMap
*
* @author <a href="mailto:harald.kuhr@gmail.com">Harald Kuhr</a>
* @version $Id: //depot/branches/personal/haraldk/twelvemonkeys/release-2/twelvemonkeys-core/src/main/java/com/twelvemonkeys/util/LinkedSet.java#1 $
*/
public class LinkedSet<E> extends AbstractSet<E> implements Set<E>, Cloneable, Serializable {
private final static Object DUMMY = new Object();
private final Map<E, Object> map;
public LinkedSet() {
map = new LinkedMap<E, Object>();
}
public LinkedSet(Collection<E> pCollection) {
this();
addAll(pCollection);
}
public boolean addAll(Collection<? extends E> pCollection) {
boolean changed = false;
for (E value : pCollection) {
if (add(value) && !changed) {
changed = true;
}
}
return changed;
}
public boolean add(E pValue) {
return map.put(pValue, DUMMY) == null;
}
public int size() {
return map.size();
}
public Iterator<E> iterator() {
return map.keySet().iterator();
}
}