A DESCRIPTION OF THE REQUEST :
Java sets & maps currently don't take "equality tests" as arguments to their constructors. We do this sort of thing in Scheme and ML all the time, and it's really useful.


JUSTIFICATION :
I am working on a project where this would come in handy. As java is now, I need to create different kinds of objects that all contain the same information but which implement different equals() functions. I know that inheritance solves this problem, but it's a little overkill when I only need the different behavior for a single hashtable.