Type families: module export of instance data constructor

[Wolfgang Jeltsch]

Am Montag, 15. Dezember 2008 02:17 schrieb Ben Horsfall:
> I have a type family
>
> class Lang term where
>   data Token term :: *
>
> with
>
> instance Lang Term where
>   newtype Token Term = T String
>
> I can't work out how to export the type constructor T from the module,
> unless I make no explict exports from the module at all.
>
>
> Ben

Hello Ben,

try

    Lang (type Token)

in the export list.

Best wishes,
Wolfgang