Re: [Haskell-cafe] Re: applicative challenge

Hi Achim On 5 May 2009, at 01:26, Achim Schneider wrote:

Conor McBride wrote:

...

Remember folks: Missiles need miffy!

Hmmmm. Iff you have something like CoPointed or Foldable, you can thread your own, Applicative, tail back into yourself and decide what you are by inspecting it.

Yeah, Applicative on its own is kind of "effects without control", or in Lindley-Wadler-Yallop parlance "oblivious". The fun starts when you just chuck in a little bit more. Copointed might be overdoing it. Even Alternative gives you quite a lot of control, without going as far as Monad.

That makes foldr the join of Hask itself, or something. Bear with me, I'm merely attempting to delurk our resident category theorists by giving them headaches.

Good luck Conor