#14366: Type family equation refuses to unify wildcard type patterns -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.2.1 checker) | Keywords: TypeFamilies, Resolution: | TypeInType Operating System: Unknown/Multiple | Architecture: Type of failure: GHC rejects | Unknown/Multiple valid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by goldfire): I'm pretty sure Agda used to reject having two different variables here, though it seems to be accepting it now. (Any Agda experts out there?) I think the pattern-signature version is a red herring, because those variables are meant to stand in for others -- indeed, that's their whole point. But I'm still not terribly bothered by this rejection. Yes, I suppose it's better to accept here, but I don't think that goal is easily achieved. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14366#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler