[Agda] Error when compiling Agda from Darcs repository by GHC 7.2

[Andreas Abel]

I did not introduce this incompatibility by intention, but since I 
switched to ghc 7.6 a while ago I did not notice.

If anyone cares for compiling with ghc 7.2 I can easily remove the 
offending type class instance.

debian stable (wheezy) has now haskell-platform (2012.2.0.0) which is 
based on ghc 7.4.1.  So maybe it is sufficient to support ghc 7.4 as 
oldest version.

Funnily, according to the docs of ghc 7.6.3, this should still be an error.

 
http://www.haskell.org/ghc/docs/7.6.3/html/users_guide/other-type-extensions.html#implicit-parameters

  You can't have an implicit parameter in the context of a class or 
instance declaration. For example, both these declarations are illegal:

   class (?x::Int) => C a where ...
   instance (?x::a) => Foo [a] where ...

That's a lie, obviously.

How can I find out when this feature entered ghc?  Does Agda compile on 7.4?

Cheers,
Andreas

On 19.03.2014 13:53, Dirk Ullrich wrote:
> Hello,
>
>
> 2014-03-19 13:15 GMT+01:00 Mateusz Kowalczyk <fuuzetsu at fuuzetsu.co.uk
> <mailto:fuuzetsu at fuuzetsu.co.uk>>:
>
>     On 19/03/14 10:54, Dirk Ullrich wrote:
>      > Hello,
>      >
>      > [...]
>      > Is GHC 7.2 not supported any longer?
>      >
>      > Dirk
>      >
>      >
>
>     7.2 is nearly 4 stable releases old, I'd be very surprised if it was
>     still supported. You should really get at least 7.6.3 and 7.8 is coming
>     out soon too.
>
>     --
>     Mateusz K.
>
> Before the last updates I could Agda even compile by GHC 7.0 (with some
> trivial patching).
> Moreover the current `Agda.cabal' says:
>
> tested-with:   GHC == 7.2.2
>                      GHC == 7.4.2
>                      GHC == 7.6.3
>
>
> Dirk
>
>
>
> _______________________________________________
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> Agda at lists.chalmers.se
> https://lists.chalmers.se/mailman/listinfo/agda
>


-- 
Andreas Abel  <><      Du bist der geliebte Mensch.

Department of Computer Science and Engineering
Chalmers and Gothenburg University, Sweden

andreas.abel at gu.se
http://www2.tcs.ifi.lmu.de/~abel/