eq and hashing (was Re: [plt-scheme] How to make unit functors?)

Ah, you're right, of course.

On Thu, 29 May 2003, [ISO-8859-1] Jens Axel Søgaard wrote:

> Jacob Matthews wrote:
>
> >Here's a real-world situation that's affected by this property: a while
> >back, Mike Machenry and I implemented a functional-sets library a using a
> >binary search tree as the underlying set representation. Of course we had
> >to have keys that would all be comparable with each other for this
> >representation to work out, but it didn't particularly matter what the
> >keys were, so we just used each item's hash value as its binary-tree key.
> >Now it sounds as though symbols inserted into these sets will get lost in
> >programs that rely on the property that 'a = 'a, so our sets have a bug.
> >
> >
>
> But if the symbols are kept in the data structure, then there shouldn't
> be a problem?
>
> --
> Jens Axel Søgaard
>
>
>
>