#16255: Visible kind application defeats type family with higher-rank result kind -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.7 checker) | Keywords: Resolution: | TypeApplications, TypeFamilies Operating System: Unknown/Multiple | Architecture: Type of failure: GHC accepts | Unknown/Multiple invalid program | Test Case: Blocked By: | Blocking: Related Tickets: #15740 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by RyanGlScott): Ah, I just realized the answer to my own question: this information is (indirectly) stored in the `tyConBinders` of the type family tycon. We'd have to do a little bit of reverse engineering to recover which type patterns had which visibility, but it should be possible (I think). Another challenge is figuring out a good `SrcSpan` to use in the error message, which we don't have any location info in `TcValidity`. Maybe we'll just have to settle for the `SrcSpan` of the entire type family equation? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16255#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler