This will affect snap-core and heist, of the things I've provided Typeable instances for.
In snap-core, deriving makes it use the internal module name, rather than the canonical location of the type. This causes issues with the Hint library, so it's worked around by using a manual instance of Typeable. Alternatively, heist involves a monad transformer. "deriving Typeable" fails for monad transformers, because it can't handle TyCons with arguments of kind other than *. So, this change will hit me for two different reasons, and sadly involve using CPP to control how things are compiled. Carl On Mon, Jul 11, 2011 at 11:18 AM, Yitzchak Gale <[email protected]> wrote: > Simon Marlow has announced[1] on the Haskell Libraries > list that the Typeable class is changing. > > The standard way to create a Typeable instance is > just to derive it. If you do that, you will not be affected > by this change. > > But it seems that many packages create Typeable > instances by explicitly using mkTyCon. If your package > does this, it will eventually break, after a deprecation > period. > > Please respond to this thread if you own a package > that will be affected by this change. > > Can someone who has quick access to the entire contents > of Hackage please do a grep and find out exactly which > packages on Hackage will be affected? Thanks. > > -Yitz > > [1] http://www.haskell.org/pipermail/libraries/2011-July/016546.html > > _______________________________________________ > Haskell-Cafe mailing list > [email protected] > http://www.haskell.org/mailman/listinfo/haskell-cafe > _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
