On Mon, 12 Nov 2012, Bas van Dijk wrote:
I like those ideas.
However this still leaves #7395 unresolved.
I do like hvr's idea of using the deriving mechanism to derive classes with DefaultSignatures.
The more I think about it the more my impression becomes that we are trying to solve a problem the complicated way where a simple solution already exists. I see the motivation behind DefaultSignatures and encountered the situation often enough that lead to the introduction of DefaultSignatures. However I always solved the problem by providing functions like genericSize or genericRnf (though I have not used Generics for default implementations). Its simple and its portable. Now with DefaultSignatures we can simplify some bits, but in order to stay portable with DefaultSignatures things get more complicated than staying portable without DefaultSignatures at all.