#7854: Constrained method type accepted in Haskell 98 mode -----------------------------+---------------------------------------------- Reporter: refold | Owner: Type: bug | Status: new Priority: normal | Component: Compiler Version: 7.6.3 | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Blockedby: Blocking: | Related: -----------------------------+---------------------------------------------- Comment(by refold): Also accepted by 7.0.4 and 7.2.1, but rejected by 6.12.1. However, it complains about `-XFlexibleContexts`, not `-XConstrainedClassMethods`: {{{ [1 of 1] Compiling Main ( Test.hs, interpreted ) Test.hs:3:0: All of the type variables in the constraint `Eq a' are already in scope (at least one must be universally quantified here) (Use -XFlexibleContexts to lift this restriction) When checking the class method: comp :: (Eq a) => a -> a -> Bool In the class declaration for `Compare' Failed, modules loaded: none. }}} -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7854#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler