Changes to Typeable

[Edward Kmett]

On Tue, Feb 14, 2012 at 11:18 AM, Iavor Diatchki
<iavor.diatchki at gmail.com>wrote:

> Hello,
>
> On Mon, Feb 13, 2012 at 5:32 PM, Edward Kmett <ekmett at gmail.com> wrote:
>>
>> There are fewer combinators from commonly used classes for working with
>> the left argument of a bifunctor, however.
>>
>
> I think that the bifunctor part of Bas's version is a bit of a red
> herring.  What I like about it is that it overloads exactly what needs to
> be overloaded---the representation of the type---without the need for any
> fake parameters.  To make things concrete, here is some code:
>
> > newtype TypeRepT t = TR TypeRep
> >
> > class Typeable t where
> >   typeRep :: TypeRepT t
> >
> > instacne Typeable Int where typeRep = TR type_rep_for_int
> > instance Typeable []  where typeRep = TR type_rep_for_list
>

I have no problem with this version either, although the Proxy type is
useful for a lot of other purposes, while this type is single use.

-Edward
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