#12820: Regression around pattern synonyms and higher-rank types -------------------------------------+------------------------------------- Reporter: goldfire | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.1 checker) | Resolution: | Keywords: 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): Fair enough. But the problem persists even with a type signature on the pattern: {{{ pattern P x <- (((\ _ -> id) :: forall b c. b -> c -> c) -> x) }}} Interestingly, adding the type signature fails in GHC 8.0.1 as well as HEAD. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12820#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler