#14907: Error message: (%,%) shows up when with accidental paren -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.5 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Poor/confusing Unknown/Multiple | error message Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- I accidentally wrote an extra closing parens in instance declaration {{{#!hs $ ghci -ignore-dot-ghci -XRankNTypes GHCi, version 8.2.1: http://www.haskell.org/ghc/ :? for help Prelude> class (Category (Src f), forall xx. xx => Eq xx)) => Functor f <interactive>:1:8: error: Unexpected type ‘Category (Src f)’ In the class declaration for ‘GHC.Classes.(%,%)’ A class declaration should have form class GHC.Classes.(%,%) a b where ... Prelude> }}} `(%,%)` shouldn't show up here, same happens on 8.5.20180105 -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14907 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler