Difference in Partial TypeFamily application between 7.8.3 & 7.8.4

magesh b magesh85 at gmail.com
Tue Jan 13 14:49:31 UTC 2015


Hi,

{-# LANGUAGE TypeFamilies, ConstraintKinds #-}

import GHC.Exts

type family TyFun a

data DictC (c :: * -> Constraint)

data DictTF (tf :: * -> *)

type Test1 = DictTF TyFun -- Fails here in 7.8.4

type Test2 = DictC Show

When I compile the above code, I'm getting the following error in 7.8.4 and
the same code works in 7.8.3.

Test.hs:11:1:
    Type synonym ‘TyFun’ should have 1 argument, but has been given none
    In the type declaration for ‘Test1’

Is this a bug or a expected behavior?
For reference, I could find two fixes to type family related bug in this
release.
https://ghc.haskell.org/trac/ghc/ticket/9433
https://ghc.haskell.org/trac/ghc/ticket/9316


Thanks & Regards,
Magesh B
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.haskell.org/pipermail/ghc-devs/attachments/20150113/b18f21fa/attachment.html>


More information about the ghc-devs mailing list