[Haskell-cafe] name for monad-like structure?
mvanier42 at gmail.com
Tue Apr 28 19:56:52 EDT 2009
Luke Palmer wrote:
> On Tue, Apr 28, 2009 at 5:33 PM, Michael Vanier <mvanier42 at gmail.com
> <mailto: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?
>>> Haskell-Cafe mailing list
>>> Haskell-Cafe at haskell.org <mailto:Haskell-Cafe at haskell.org>
>> 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.
Got it. Thanks.
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