#12553: Reference kind in a type instance declaration defined in another instance declaration -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Resolution: | Keywords: TypeInType 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 goldfire): I think the following clarifying comment might help: When declaring a type family like {{{ type family F a :: u }}} the result kind `u` is actually a ''parameter'' to `F`. This type family is the same as {{{ type family G u a :: u }}} except that in `F`, the `u` is invisible. So there are no existential kinds involved. Does this help? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12553#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler