Hi Brian, Thank you for starting the thread. We (Martin Sulzmann and me) proposed a type class extension which allows modular extension of superclasses (a complement of subclass extension). The idea has been shown to be particularly useful in (but not limited to) encodings of generic programming with type classes. A brief introduction of the proposal is documented in our wiki: http://taichi.ddns.comp.nus.edu.sg/taichiwiki/GPHomePage. I will try to add it as a link in yours soon. A more detailed and formal description of the proposal can be found in our Workshop on Generic Programming 06 paper which is available at http://www.comp.nus.edu.sg/~sulzmann http://web.comlab.ox.ac.uk/oucl/work/meng.wang/ Regards, Meng -W-M- @ @ | \_/ On Tue, 9 Jan 2007, Brian Hulley wrote:
Simon Peyton-Jones wrote:
One of the great things about John's class-alias proposal is that John worked out a lot of details and captured them in a web page, rather than it getting buried in an email thread.
If you have ideas to refine his proposal, it'd be good to see if, with him, you can come up with a unified design, and again capture it in a Wiki page or something.
I've started a page at http://www.haskell.org/haskellwiki/Class_system_extension_proposal John - I haven't added anything about your class alias proposal because you've copyrighted your proposal and I don't want to do the wrong thing ;-) Can you add a section for your proposal (or containing a link to your proposal) on his page?
Please could everyone who has any other ideas about class system extensions add them to the page above so that we have a central location. Hopefully it will gradually become clear what all the issues are and perhaps a path for trying to implement some extensions in order of difficulty.
Thanks, Brian. -- http://www.metamilk.com _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe