My previous message was about robust-ifying the conversion from: TH.Syntax -> HsSyn but the other direction has very similar problems. The functions in DsMeta convert: HsSyn -> TH.Syntax Unfortunately, of course TH does not implement all of GHC's extensions, so the desugaring can fall over badly. The right thing to do is presumably to make the desugarer monad support failure and errors, like the type checker monad does, and fail more gracefully. Again, is there anyone who'd be prepared to take this on? Simon -----Original Message----- From: glasgow-haskell-bugs-bounces@haskell.org [mailto:glasgow-haskell-bugs-bounces@haskell.org] On Behalf Of SourceForge.net Sent: 16 July 2004 10:10 To: noreply@sourceforge.net Subject: [ ghc-Bugs-992199 ] Template crash on existential types Bugs item #992199, was opened at 2004-07-16 09:08 Message generated for change (Settings changed) made by mm_aa You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=108032&aid=992199&grou p_id=8032 Category: Compiler Group: 6.2.1 Status: Open Resolution: None Priority: 5 Submitted By: Mike Aizatsky (mm_aa) Assigned to: Nobody/Anonymous (nobody)
Summary: Template crash on existential types
Initial Comment: Windows XP D:\Tools\ghc>ghc-6.2.1\bin\ghc.exe -fglasgow-exts foo.hs ghc.exe: panic! (the `impossible' happened, GHC version 6.2.1): deSugar/DsMeta.hs:286: Non-exhaustive patterns in function repC module Foo where import Language.Haskell.THSyntax class MyInterface a where foo :: a -> Int data AnyMyInterface = forall a. (MyInterface a) => AnyMyInterface a test = do{ d <- unQ(reifyDecl AnyMyInterface) ; print d } ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=108032&aid=992199&grou p_id=8032 _______________________________________________ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs