#14140: Better treatment for dataToTag -------------------------------------+------------------------------------- Reporter: simonpj | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: datacon-tags Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by dfeuer): For derived instances, might it make sense to write this? {{{#!hs eqOS :: OS -> OS -> Bool eqOS a b | dataToTag a /= dataToTag b = False eqOS (OtherOS s1) (OtherOS s2) = s1 == (s2 :: String) eqOS _ _ = False }}} Sometimes this will be better; sometimes it will be worse. But I don't think it's likely to do anything silly. Of course, even if we do that, we probably want to try to make the compiler cleverer too. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14140#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler