#11355: TypeApplications + RankNTypes permits "impredicativity" -------------------------------------+------------------------------------- Reporter: adamgundry | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.11 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- I was slightly surprised to discover that the combination of `TypeApplications` and `RankNTypes` allows impredicative instantiations, for example: {{{#!hs map @(forall a . a) :: ((forall a. a) -> b) -> [forall a. a] -> [b] }}} Is this desirable, or should it require `ImpredicativeTypes`? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11355 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler