#13391: PolyKinds is more permissive in GHC 8 -------------------------------------+------------------------------------- Reporter: crockeea | Owner: (none) Type: bug | Status: patch Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 Resolution: | Keywords: TypeInType Operating System: Unknown/Multiple | Architecture: Type of failure: GHC accepts | Unknown/Multiple invalid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D3859 Wiki Page: | -------------------------------------+------------------------------------- Comment (by bgamari): One non-obvious implication of this change is that program like the `KindEqualities` test from the testsuite will now require that users enable `TypeInType` and consequently will manually need to quantify over the kind variables of their tycon's signature. For instance, currently `KindEqualities` has, {{{#!hs data TyRep :: k -> * where TyInt :: TyRep Int -- etc. }}} This needs to become, {{{#!hs data TyRep :: forall k. k -> * where TyInt :: TyRep Int -- etc. }}} This is documented in Phab:D3966. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13391#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler