[Haskell-cafe] The difficulty of designing a sequence class

[Jim Apple]

On 7/31/06, ajb at spamcop.net <ajb at spamcop.net> wrote:
> G'day all.
>
> Quoting David Menendez <zednenem at psualum.com>:
>
> > That's a tough call to make. Changing the kind of Sequence to * from *
> > -> * means losing the Functor, Monad, and MonadPlus superclasses and all
> > the various maps and zips.
>
> Perhaps Functor/Monad/etc are the culprits here.

Indeed. See Oleg's message from a few months back where he shows that
we can get John Hughes Restricted Data Types (Set is a Monad) by
adding parameters to type classes:

http://www.haskell.org//pipermail/haskell-prime/2006-February/000498.html
http://hackage.haskell.org/trac/haskell-prime/ticket/98

Jim