[Haskell-cafe] Re: Typeclass vs. Prolog programming

Jason Dagit dagit at eecs.oregonstate.edu
Thu Sep 28 03:19:57 EDT 2006

On 9/27/06, oleg at pobox.com <oleg at pobox.com> wrote:
> This message is intended as a long answer to Michael Shulman's
> question (Re: variadic functions and typeCast) and Jason Dagit's
> question (Re: Duplicate Instance problem). Incidentally, the short
> answer to Jason Dagit's question is `constraints are disregarded
> during instance selection'. The answer to Michael Shulman is yes.

Hmm...Perhaps I'm just sleepy but I read through the descriptions
below and I'm still not sure if what I want to do is easy or extremely
difficult.  I think you're suggesting that I should use something like
TypeCast to control the unification if I want to get rid of my
duplicate instances problem?

I'll re-read this a few times and look at the TypeCast stuff.  I feel
like this is quite a bit over my head at the moment, but your
description is very good and hopefully it will make more sense in the


More information about the Haskell-Cafe mailing list