// $Id: SetTable.java,v 1.1.1.1 1999/12/05 22:19:52 mpp Exp $

package IR2;

import java.util.Hashtable;

public class SetTable extends Hashtable {

  public synchronized Object get(Object key) {
    Set set = (Set) super.get(key);
    if (set == null) {
      set = new Set();
      super.put(key, set);
    }
    return set;
  }

  public synchronized Object put(Object key, Object value) {
    Set set = (Set) get(key);
    set.add(value);
    return set;
  }

  public synchronized Object remove(Object key, Object value) {
    Set set = (Set) get(key);
    set.remove(value);
    return set;
  }

}