#12923: MultiParamTypeClasses + ExtendedDefaultRules -------------------------------------+------------------------------------- Reporter: amindfv | Owner: Type: feature request | Status: patch Priority: normal | Milestone: 8.2.1 Component: Compiler | Version: 8.0.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D2816 Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): I don't think that rule will work. As the user manual page says, the list type `[] :: * -> *` is in the list of type defaults, so that higher-kinded variables can be defaulted too. See #10971. So we can't restrict to *. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12923#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler