#12187: Clarify the scoping of existentials for pattern synonym signatures -------------------------------------+------------------------------------- Reporter: mpickering | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Resolution: | Keywords: | PatternSynonyms Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #12108 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by goldfire): And how do we reject {{{ pattern Bad :: () => forall a. T a }}} Do we follow your proposed rules and then check to make sure that there are no existentials in the (expanded) return type? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12187#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler