#16394: GHC internal error while typechecking of instance definition -------------------------------------+------------------------------------- Reporter: Day1721 | Owner: (none) Type: bug | Status: new Priority: low | Milestone: Component: Compiler (Type | Version: 8.6.3 checker) | Resolution: | Keywords: Operating System: Linux | 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 simonpj): Happily, HEAD gives {{{ T16394.hs:9:10: error: Illegal class instance: `C a => C b => C (a, b)' Class instances must be of the form context => C ty_1 ... ty_n where `C' is a class | 9 | instance C a => C b => C (a, b) where | ^^^^^^^^^^^^^^^^^^^^^^ }}} Would someone like to add a regression test and close this? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16394#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler