22 Mar
2016
22 Mar
'16
6:08 a.m.
Even better might be to use GHC 8 custom type errors in the constraint head to explain what 'Impossible' means. On Tue, 22 Mar 2016 10:21 am Henning Thielemann, < lemming@henning-thielemann.de> wrote:
On Wed, 24 Feb 2016, Chris Allen wrote:
You can't not-include the instances because we'll just end up with orphans so that's not cricket I think.
We could define
instance Impossible a => Functor ((,,) a b) where
where Impossible is a non exported class. _______________________________________________ Libraries mailing list Libraries@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/libraries