No, I've not tested against head. I'd not heard anything new about that! That sounds exciting. Sorry about the noise if it's all finished already.
David On Thu, Oct 22, 2015 at 9:57 AM, Richard Eisenberg <e...@cis.upenn.edu> wrote: > The Coercible solver has evolved steadily. It should know that (Coercible a b > <=> Coercible b a). Do you have a concrete example of where it's not doing > this? Have you tested against HEAD? > > Thanks, > Richard > > On Oct 22, 2015, at 9:56 AM, David Feuer <david.fe...@gmail.com> wrote: > >> At present, any time we write a function with a `Coercible` >> constraint, we must take great care to choose `Coercible a b` or >> `Coercible b a` depending on which will ultimately lead to fewer silly >> conversions. This is particularly sad because the whole Coercible >> mechanism guarantees that these have exactly the same run-time >> representation, and because People Wiser Than Me believe Coercible >> should *always* remain symmetric. My (admittedly reptilian) brain >> wonders what it would take to tell the type checker that >> >> forall a b . Coercible a b ~ Coercible b a >> >> and have it over with. >> >> David Feuer >> _______________________________________________ >> ghc-devs mailing list >> ghc-devs@haskell.org >> http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs > _______________________________________________ ghc-devs mailing list ghc-devs@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs
