#14331: Overzealous free-floating kind check causes deriving clause to be rejected -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.2.1 checker) | Resolution: | Keywords: deriving Operating System: Unknown/Multiple | Architecture: Type of failure: GHC rejects | Unknown/Multiple valid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by goldfire): But I see `instance C (a :: k) D` as fully equivalent to `instance forall k (a :: k). C a D`. They just make different things explicit, but both declarations have the same static and dynamic semantics. And, I don't quite agree that clauses in a `deriving` are macro-like. They are types of kind `... -> Type -> Constraint`, where the `...` may be empty. My desire to put `forall` in there is more macro-like, I admit... but no more so than the syntax for pattern synonym types or even GADT constructor types. I believe that you are genuinely confused here. But I'm afraid I'm equally confused as to why you're confused. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14331#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler