On Wed, Jun 5, 2013 at 8:46 AM, Roman Cheplyaka <roma@ro-che.info> wrote:
* TP <paratribulations@free.fr> [2013-06-05 00:37:36+0200]
> Roman Cheplyaka wrote:
>
> > Try adding
> >
> >   deriving instance Typeable 'Zero
> >   deriving instance Typeable a => Typeable ('Succ a)
> >
> > to your module.
> >
> > (I haven't tested it — you might need to tweak it a bit.)
>
> Thanks Roman.
> Unfortunately, I already tried that (without the constraint "Typeable a =>",
> what a fool), but it did not work. The error is the same with the
> constraint:
>
>     Derived typeable instance must be of form (Typeable 'Succ)
>     In the stand-alone deriving instance for
>       ‛Typeable a => Typeable (Succ a)’
>
> What is the problem?

Oh, it should probably be simply

  deriving instance Typeable 'Zero
  deriving instance Typeable 'Succ

Yes, that's how it should be. Please let me know if that
doesn't work.

(Sorry for taking so long to reply to this...)


Cheers,
Pedro
 

Roman

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