#8953: Reifying poly-kinded type families misses kind annotations -------------------------------------+------------------------------------ Reporter: goldfire | Owner: goldfire Type: bug | Status: new Priority: normal | Milestone: Component: Template Haskell | Version: 7.9 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: None/Unknown | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: -------------------------------------+------------------------------------ Changes (by goldfire): * owner: => goldfire Comment: Unfortunately, I think the solution is to include kind annotations on ''every'' variable being reified in this context. The problem is that the declarations above do ''not'' come from source Haskell -- the declarations are reconstructed from Core. In Core, every variable has a known kind, so kind annotations do not exist. Although I can imagine some big, complicated inference algorithm that would detect exactly when the annotation is necessary in user code. I don't see a simple way to do this. And, I think the complicated thing has a very wrong power-to-weight ratio. Of course, adding in all the kind annotations is a breaking change that will likely break existing code that reifies type families. Happily, the implementation is easy. If no one objects to this change, I'll put it in in due course. (Not for 7.8!) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8953#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler