[Typeable2] Re: ANNOUNCE: GHC 7.8.1 Release Candidate 1

[Christian Maeder]

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.Maeder at 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 at haskell.org
>>> http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
>>>
>>
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