Re: ConstraintKinds seems to be automatically enabled

On Thu, May 4, 2017 at 6:42 PM, Wolfgang Jeltsch wrote: > In my previous e-mail, I showed some code that uses the Constraint kind. > I forgot to enable the ConstraintKinds extension though, but GHC 8.0.1 > did not complain. Is this a bug? > I think it's a known side

ConstraintKinds seems to be automatically enabled

Hi! In my previous e-mail, I showed some code that uses the Constraint kind. I forgot to enable the ConstraintKinds extension though, but GHC 8.0.1 did not complain. Is this a bug? All the best, Wolfgang ___ Glasgow-haskell-users mailing list

Untouchable type variables

Hi! Today I encountered for the first time the notion of an “untouchable” type variable. I have no clue what this is supposed to mean. A minimal example that exposes my problem is the following: > {-# LANGUAGE Rank2Types, TypeFamilies #-} >  > import GHC.Exts (Constraint) >  > type family F a b