Set.java

// $Id$
//
// Cassowary Incremental Constraint Solver
// Original Smalltalk Implementation by Alan Borning
// This Java Implementation by Greg J. Badros, <gjb@cs.washington.edu>
// http://www.cs.washington.edu/homes/gjb
// (C) 1998, 1999 Greg J. Badros and Alan Borning
// See ../LICENSE for legal details regarding this software
//
// Set
// Encapsulate a mathematical "Set" ADT using java's
// hash table.  Just a convenience wrapper of the java.util.Hashtable class.

package EDU.Washington.grad.gjb.cassowary;

import java.util.*;

class Set {
  public Set()
    { hash = new Hashtable(); }

  public Set(int i)
    { hash = new Hashtable(i); }

  public Set(int i, float f)
    { hash = new Hashtable(i,f); }

  public Set(Hashtable h) 
    { hash = h; }

  public boolean containsKey(Object o)
    { return hash.containsKey(o); }

  public boolean insert(Object o)
    { return hash.put(o,o) == null? true: false; }

  public boolean remove(Object o)
    { return hash.remove(o) == null? true: false; }

  public void clear()
    { hash.clear(); }

  public int size()
    { return hash.size(); }

  public boolean isEmpty()
    { return hash.isEmpty(); }

  public Object clone()
    { return new Set((Hashtable) hash.clone()); }

  public Enumeration elements()
    { return hash.elements(); }

  public String toString()
  { 
    StringBuffer bstr = new StringBuffer("{ ");
    Enumeration e = hash.keys();
    if (e.hasMoreElements())
      bstr.append(e.nextElement().toString());
    while ( e.hasMoreElements() ) {
      bstr.append(", " + e.nextElement());
    }
    bstr.append(" }\n");
    return bstr.toString();
  }
  
  private Hashtable hash;
}