#12087: Inconsistency in GADTs? -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: (none) Type: task | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Resolution: | Keywords: GADTs Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #11540 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * status: patch => new * owner: RyanGlScott => (none) * differential: Phab:D3831 => Comment: Richard and I decided that the approach taken in Phab:D3831 wasn't the best course of action. Although it would allow exotic GADT constructor type signatures like `Ord a => Eq a => a -> F a`, it would come at a steep price: GHC would normalize the type signature to `(Ord a, Eq a) => a -> F a` behind the scenes, so you'd no longer see the type you originally wrote when you queried it with `:type +v`. For this reason, I've decided to try to improve the current error message instead, which doesn't make it very clear what the underlying problem is (nor how to fix it). Patch coming soon. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12087#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler