While it's true that Maybe's kind is (* -> *), there still may be a better answer to your question, which asks, "Is there a way to get a polykinded promoted type?" Maybe isn't polykinded, but it's also not promoted. With
data Proxy a = P
we get (Proxy :: k -> *). But that's not promoted either. On the other hand we have ('Just :: k -> Maybe k), which is promoted and polykinded, but maybe not what you want.
Does this help?
Richard
On Dec 8, 2014, at 5:52 PM, Gautier DI FOLCO
Hi all,
Is there a way to get a Polykinded promoted type. For example with Maybe I get: data Maybe a = Just a | Nothing Prelude> :k Maybe Maybe :: * -> *
Is it possible to get a k -> *? If so, how can I do that?
Thanks in advance for your help, Regards. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe