#14045: Data family instances must list all patterns of family, despite documentation's claims to the contrary -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.3 checker) | Resolution: | Keywords: TypeFamilies Operating System: Unknown/Multiple | Architecture: Type of failure: GHC rejects | Unknown/Multiple valid program | Test Case: Blocked By: | Blocking: Related Tickets: #12369 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by simonpj): * cc: goldfire (added) Comment: To me the `k` argument to `Sing` looks like an invisible (implicit) one. So you should need visible kind application to use it in an invocation, something like {{{ instance C (z :: Bool) where data Sing :: Bool -> Type where SFalse :: Sing @False STrue :: Sing @True }}} Let's see what Richard says. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14045#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler