Class TreeSet

classpath/java/util/TreeSet.java:16–214

import avian.Cell;

public class TreeSet<T> extends AbstractSet<T> implements Collection<T> {
  private PersistentSet<Cell<T>> set;

  public TreeSet(final Comparator<T> comparator) {
    set = new PersistentSet(new Comparator<Cell<T>>() {
      public int compare(Cell<T> a, Cell<T> b) {
        return comparator.compare(a.value, b.value);
      }
    });
  }

  public TreeSet() {
    this(new Comparator<T>() {
        public int compare(T a, T b) {
          return ((Comparable) a).compareTo(b);
        }
    });
  }

  public TreeSet(Collection<? extends T> collection) {
    this();

    for (T item: collection) {
      add(item);
    }
  }

  public T first() {
    if (isEmpty()) throw new NoSuchElementException();

    return set.first().value().value;
  }

  public T last() {
    if (isEmpty()) throw new NoSuchElementException();

    return set.last().value().value;
  }
  
  public Iterator<T> iterator() {
    return new MyIterator<T>(set.first());
  }

  public Iterator<T> descendingIterator() {
    return new MyIterator<T>(set.last(), true);
  }

  public String toString() {
    return avian.Data.toString(this);
  }

  public boolean add(T value) {
    PersistentSet.Path<Cell<T>> p = set.find(new Cell(value, null));
    if (p.fresh()) {
      set = p.add();
      return true;
    }
    return false;