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

On 7/31/06, ajb@spamcop.net <ajb@spamcop.net> wrote:

G'day all.

Quoting David Menendez <zednenem@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