[Haskell-cafe] name for monad-like structure?

[Luke Palmer]

On Tue, Apr 28, 2009 at 5:33 PM, Michael Vanier <mvanier42 at 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 listHaskell-Cafe at haskell.orghttp://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
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