#11793: Confusing type error from constrained class method -------------------------------------+------------------------------------- Reporter: gridaphobe | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.0.1 Component: Compiler | Version: 8.0.1-rc2 Resolution: | Keywords: error-message Operating System: Unknown/Multiple | Architecture: Type of failure: Incorrect | Unknown/Multiple warning at compile-time | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by Iceland_jack): Is this intended? {{{ $ ghci -XImplicitParams -XConstrainedClassMethods -ignore-dot-ghci GHCi, version 8.1.20160117: http://www.haskell.org/ghc/ :? for help Prelude> class C a where foo :: (?x::Int) => a -> a Prelude> class C a where foo :: ?x::Int => a -> a <interactive>:2:32: error: parse error on input ‘=>’ Prelude> }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11793#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler