On Tue, Apr 28, 2009 at 5:33 PM, Michael Vanier <mvanier42@gmail.com> wrote:
Tony Morris wrote: 
Michael Vanier wrote:
  
I've stumbled upon a structure that is like a weaker version of a
monad, one that supports return and >> but not >>=.  Has anyone seen
this before, and if so, does it have a standard name?

Mike


_______________________________________________
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe

    
Are you sure it supports
(>>) :: m a -> m b -> m b

and not
mplus :: m a -> m a -> m a ?
Yeah, you're right.  It's basically a monad where the type a is fixed to be (), so you just have

(>>) :: m () -> m () -> m ()

That's a monoid.

Luke