#15869: Discrepancy between seemingly equivalent type synonym and type family -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.6.2 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 RyanGlScott): To be clear, I am in agreement with you that the program in the second bullet point of comment:5 should be rejected if `ImpredicativeTypes` is not enabled. I am simply wondering if it being accepted //with// `ImpredicativeTypes` enabled should count as a bug in its own right. (It's such a squirrelly extension that I can never tell whether it's working as intended or not.) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15869#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler