[Haskell-cafe] Confused about type seen in the wild
Andres Löh
andres at well-typed.com
Thu Apr 10 18:51:26 UTC 2014
> I don't have a GHC 7.8 handy. Can you check to see if:
>
> whee :: Show a => Eq a => (a -> Bool)
>
> works over there?
Yes, it does. I also see no problem with this one. Even this works
(but funnily enough, it requires RankNTypes, even though it translates
to the same type):
let whee :: a -> Show a => Eq a => Bool; whee = undefined
None of these are kind errors though. And while I don't know if it's
clearly specified what exactly is possible, it makes sense to me to
allow these.
Cheers,
Andres
--
Andres Löh, Haskell Consultant
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