Mega Code Archive
Indexed Set
<![CDATA[
//package gr.forth.ics.util;
import java.util.AbstractCollection;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
/**
*
* @author Andreou Dimitris, email: jim.andreou (at) gmail (dot) com
*/
public class IndexedSet<T> extends AbstractCollection<T> implements Set<T> {
private final List<T> list = new ArrayList<T>();
private final Set<T> set = new HashSet<T>();
public int size() {
return list.size();
}
@Override
public boolean isEmpty() {
return list.isEmpty();
}
@Override
public boolean contains(Object o) {
return set.contains(o);
}
public Iterator<T> iterator() {
return new Iterator<T>() {
Iterator<T> realIterator = list.iterator();
T current = null;
public boolean hasNext() {
return realIterator.hasNext();
}
public T next() {
T next = realIterator.next();
current = next;
return next;
}
public void remove() {
realIterator.remove();
set.remove(current);
current = null;
}
};
}
@Override
public Object[] toArray() {
return list.toArray();
}
@Override
public <T> T[] toArray(T[] a) {
return list.toArray(a);
}
@Override
public boolean add(T e) {
boolean added = set.add(e);
if (added) {
list.add(e);
}
return added;
}
@Override
public boolean remove(Object o) {
boolean removed = set.remove(o);
if (removed) {
list.remove(o);
}
return removed;
}
@Override
public boolean containsAll(Collection<?> c) {
return set.containsAll(c);
}
@Override
public boolean retainAll(Collection<?> c) {
boolean removed = false;
Iterator<T> it = list.iterator();
while (it.hasNext()) {
T next = it.next();
if (!c.contains(next)) {
it.remove();
set.remove(it);
removed = true;
}
}
return removed;
}
public void clear() {
set.clear();
list.clear();
}
public T get(int index) {
return list.get(index);
}
public T remove(int index) {
T t = list.get(index);
remove(t);
return t;
}
}
]]>