I think you need to import Data.OldTypeable to get Typeable2 and friends. Pedro may remember more of the reasoning about backward compatibility.
| -----Original Message----- | From: Christian Maeder [mailto:christian.mae...@dfki.de] | Sent: 20 February 2014 16:09 | To: Simon Peyton Jones; Daniil Frumin | Cc: glasgow-haskell-users@haskell.org | Subject: Re: [Typeable2] Re: ANNOUNCE: GHC 7.8.1 Release Candidate 1 | | With "TypeableN " I mean, Typeable1, Typeable2, etc. | Typeable2 was not supported (below) by ghc-7.8-rc1. | | Where is the "backward compat"? | | In fact, Typeable and Typeable2 mean the same thing for ghc-7.8-rc1 and | ghc-7.6 resp.! | | C. | | Am 20.02.2014 17:00, schrieb Simon Peyton Jones: | > | Can you not simply let ghc-7.8 interpret TypeableN as Typeable? | > | > Not really: ghc-7.8 does still support TypeableN I think (for backward | compat reasons). So it can't take it to mean two different things. | > | > | -----Original Message----- | > | From: Glasgow-haskell-users [mailto:glasgow-haskell-users- | > | boun...@haskell.org] On Behalf Of Christian Maeder | > | Sent: 20 February 2014 15:51 | > | To: Daniil Frumin | > | Cc: glasgow-haskell-users@haskell.org | > | Subject: Re: [Typeable2] Re: ANNOUNCE: GHC 7.8.1 Release Candidate 1 | > | | > | Yes, changing Typeable2 to Typeable in: | > | | > | {-# LANGUAGE StandaloneDeriving, DeriveDataTypeable #-} ... | > | deriving instance Typeable Gr | > | | > | goes through with ghc-7.8-rc1. | > | | > | However, this change refuses to compile with ghc-7.6.3: | > | | > | Expecting two more arguments to `Gr' | > | In the stand-alone deriving instance for `Typeable Gr' | > | | > | This is unfortunate, because I need to add conditional compilation | > | to make my code compilable for the two most recent major versions of | GHC. | > | | > | Can you not simply let ghc-7.8 interpret TypeableN as Typeable? | > | | > | Cheers Christian | > | | > | Am 13.02.2014 15:36, schrieb Daniil Frumin: | > | > I think that the preferred solution is to get rid of the custom | > | > Typeable(2) instances and just derive Typeable | > | > | > | > On Thu, Feb 13, 2014 at 5:22 PM, Christian Maeder | > | > <christian.mae...@dfki.de> wrote: | > | >> Hi, | > | >> | > | >> with ghc-7.8.20140130 I get the compilation error: | > | >> | > | >> Not in scope: type constructor or class 'Typeable2' | > | >> Perhaps you meant 'Typeable' (imported from Data.Typeable) | > | >> | > | >> What is the recommend way to adjust my code or my dependencies? | > | >> | > | >> Cheers Christian | > | >> | > | >> Am 03.02.2014 23:35, schrieb Austin Seipp: | > | >>> | > | >>> We are pleased to announce the first release candidate for GHC | > | 7.8.1: | > | >>> | > | >>> http://www.haskell.org/ghc/dist/7.8.1-rc1/ | > | >>> http://www.haskell.org/ghc/docs/7.8.1-rc1/html/ | > | >>> | > | >>> This includes the source tarball and bindists for Windows, | > | >>> Linux, OS X, FreeBSD, and Solaris, on x86 and x86_64. There is a | > | >>> signed copy of the SHA256 hashes available (attached) using my | > | >>> GPG key (keyid 0x3B58D86F). | > | >>> | > | >>> We plan to make the 7.8.1 RC2 release quite soon, as we're aware | > | >>> of some existing issues. | > | >>> | > | >>> Please test as much as possible; bugs are much cheaper if we | > | >>> find them before the release! | > | >>> | > | >>> | > | >>> | > | >>> | > | >>> _______________________________________________ | > | >>> Glasgow-haskell-users mailing list | > | >>> Glasgow-haskell-users@haskell.org | > | >>> http://www.haskell.org/mailman/listinfo/glasgow-haskell-users | > | >>> | > | >> | > | >> _______________________________________________ | > | >> Glasgow-haskell-users mailing list | > | >> Glasgow-haskell-users@haskell.org | > | >> http://www.haskell.org/mailman/listinfo/glasgow-haskell-users | > | > | > | > | > | > | > | | > | _______________________________________________ | > | Glasgow-haskell-users mailing list | > | Glasgow-haskell-users@haskell.org | > | http://www.haskell.org/mailman/listinfo/glasgow-haskell-users | > | > _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users