Re: Set and .equals() semantics

Jaakko Kangasharju wrote:


This is a good point, actually. I hadn't thought about it that way.
EnumSet can return the original object of course, because there is only
one object, but that's a specific case.

OK, I withdraw my previous whining. Map it is.

Here's my version. It needs more methods wrapped, but I think it's
pretty simple from here. Just pass the methods to the HashMap. Note I
have not actually tested the iterator. Hmm, once you count testing,
this is moving a tad beyond the "kindergarten" stage...

Maybe a new interface too, SetWithFind.... more code and testing...

package hashsetwithfind;

import java.util.AbstractSet;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Set;

public class HashSetWitFind<E> extends AbstractSet<E>
         implements Set<E>
{

     private final HashMap<E,E> set =
             new HashMap<E,E>();

     @Override
     public boolean add( E e )
     {
         set.put(e, e);
         return true;
     }

     @Override
     public boolean contains( Object o )
     {
         return set.containsKey(o);
     }

     @Override
     public boolean remove( Object b )
     {
         if( set.containsKey( b ) )
         {
             set.remove( b );
             return true;
         }
         return false;
     }

     @Override
     public Iterator<E> iterator()
     {
         return set.values().iterator();
     }

     @Override
     public int size() {
         return set.size();
     }

     public E find( E e )
     {
         return set.get(e);
     }

}