#16140: Cannot create type synonym for quantified constraint without ImpredicativeTypes -------------------------------------+------------------------------------- Reporter: Ashley Yakeley | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.6.3 Resolution: | Keywords: | QuantifiedConstraints, | ImpredicativeTypes 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 simonpj):
I'm confused—didn't you say (in comment:3) that checkValidType should use check_pred_ty for Constraint-kinded things?
Yes I did, but that's not what has been implemented! Nor should it be, I think. comment:12 (at the top) says exactly when `check_pred_ty` is used. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16140#comment:17 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler