#12792: Wrong error message when using a data type as a class instance head -------------------------------------+------------------------------------- Reporter: nomeata | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Incorrect | Unknown/Multiple error/warning at compile-time | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by nomeata): Do we need full kind-checking? The renamer already knows the concrete TyCon that is heading the instance. Shouldn’t `isClassTyCon` be sufficient here? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12792#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler