/**
*
* @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;
}
}
