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On Feb 14, 2012, at 3:00 AM, Roman Leshchinskiy <r...@cse.unsw.edu.au> wrote: > On 13/02/2012, at 11:10, Simon Peyton-Jones wrote: > >> | Should there perhaps be a NewTypeable module which could then be renamed >> | into Typeable once it is sufficiently well established? >> >> I started with that idea, but there would be a 2-stage process: >> * Step 1: (when PolyTypable becomes available) People change to import >> Data.PolyTypeable >> * Step 2: (when PolyTypeable becomes Typeable) People change back to >> Data.Typeable > > The problem is that libraries generally have to support multiple versions of > GHC and this would become harder. But that isn't too bad, preprocessor magic > solves it. It would be easier if we could define Typeable1 etc. as an alias > for Typeable (since they now mean the same thing) but we don't have class > aliases. No, but we do have the ability to make type aliases for classes now that we have constraint kinds, and typeOf1, etc. are amenable to the same implementation technique as typeOf. > My main objection is still the fact that a central library will now rely on a > highly experimental language feature which isn't even really available in a > GHC release yet (my understanding is that support for polykinds in 7.4 is > shaky at best). IMO, this should be avoided as a matter of policy. I realise > that others are much less conservative than me in this respect, though. > > Roman > > > > _______________________________________________ > Libraries mailing list > librar...@haskell.org > http://www.haskell.org/mailman/listinfo/libraries _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
