[Haskell-cafe] SYB: extending a generic reader with a type class

[José Pedro Magalhães]

Hi,

I don't think you can do that, since `ext` relies on Typeable and Typeable
only works for monomorphic types.


Cheers,
Pedro

On Wed, Feb 2, 2011 at 20:31, Sugar Bzzz <sugarbzzzz at gmail.com> wrote:

> Dear -cafe,
>
> Is it possible to extend a generic reader (extR / ext1R from syb) with a
> type class?
>
>
> For example, let
>
> foo :: (Integral a) => SomeMonad a
>
> I could write:
>
> reader = ... `extR` (foo :: SomeMonad Int) `extR` (foo :: SomeMonad
> Integer)
>
> However, that is tedious.  Could I do something like
>
> reader = ... `extR` foo
>
> and have it apply to all instances of Integral?
>
>
> I hope I am being clear.
>
> Thank you.
>
> _______________________________________________
> Haskell-Cafe mailing list
> Haskell-Cafe at haskell.org
> http://www.haskell.org/mailman/listinfo/haskell-cafe
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.haskell.org/pipermail/haskell-cafe/attachments/20110202/94ccabd4/attachment.htm>