On 09.02.2011 23:16, Cristiano Paris wrote:
On Wed, Feb 9, 2011 at 19:33, Alexey Khudyakov
<alexey.sklad...@gmail.com> wrote:
...
If Private is not exported one cannot add instances to PRead.
Nice trick. I would have thought of hiding the classes PRead and
PWrite but I'm not sure if it could break the code.
It shouldn't but it would be impossible to write signatures for
polymorphic functions which use thoose type classes.
foo :: PWrite p => Sealed p Int <-- impossible to write
foo = ...
_______________________________________________
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
