#4220: EmptyDataDecls + DeriveFunctor == Panic! -------------------------------------+------------------------------------- Reporter: conal | Owner: simonpj Type: bug | Status: closed Priority: normal | Milestone: 7.0.1 Component: Compiler | Version: 6.12.3 Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Compile-time | Test Case: crash | deriving/should_compile/T4220 Blocked By: | Blocking: Related Tickets: #4302 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by thomie): * related: => #4302 Comment: commit 6efa3901fd6f1583fb654bd3659e88702dfd579a {{{ Author: simonpj@microsoft.com <unknown> Date: Thu Aug 12 13:13:19 2010 +0000 Fix Trac #4220 For deriving Functor, Foldable, Traversable with empty data cons I just generate a null equation f _ = error "urk" There are probably more lurking (eg Enum) but this will do for now. }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/4220#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler