#10760: Conflicting typefamily instances not reported with polykinds -------------------------------------+------------------------------------- Reporter: steely | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.3 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: GHC accepts Unknown/Multiple | invalid program Test Case: | Blocked By: Blocking: | Related Tickets: Differential Revisions: | -------------------------------------+------------------------------------- GHC fails to report conflicting instances for a open polykinded type family when the two resulting types have different kinds. I would expect conflicts to be detected regardless of the concrete kind of the result. Minimal Example: {{{#!hs type family Bar a :: k type instance Bar Int = Int --type instance Bar Int = Bool -- Conflict detected type instance Bar Int = [] -- Conflict NOT detected }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10760 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler