#14190: Typeable imposes seemingly redundant constraints on polykinded instances -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.4.1 Component: Compiler (Type | Version: 8.2.1 checker) | Resolution: | Keywords: Typeable Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by dfeuer): I think the ideal ergonomics with the best performance would likely be to leave the class as it is, extract the typerep-of-kind info as needed in the `DFun`s, and hack the constraint solver to let it solve `Typeable k` from `Typeable (a :: k)`. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14190#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler