[Haskell-cafe] Re: Libraries need a new owner

[Don Stewart]

ahey:
> Don Stewart wrote:
> >ahey:
> >>Hello Folks,
> >>
> >>As some of you will be aware, I have been working on various Map
> >>implementations that currently live here..
> >>
> >>http://code.haskell.org/collections/collections-ghc6.8
> >>
> >>The libs in question being Data.Tree.AVL, Data.Trie.General and a few
> >>other bits like Data.COrdering and the AVL based Data.Map/Set clones.
> >>
> >>Well, I have decided to stop work on these. So they need a new owner if
> >>they're going to go anywhere. If anyone is interested in the job then I
> >>suggest they contact myself or Jean-Philippe Bernardy.
> >>
> >>Of course I will be happy to provide any help or advise anyone who takes
> >>over these libs may feel they need from me. I might even contribute a
> >>few patches from time to time myself :-)
> >>
> >>Thanks
> >
> >How about we propose this work be done for Summer of Code.
> >
> >I've created a ticket here:
> >
> >    http://hackage.haskell.org/trac/summer-of-code/ticket/1549
> >
> >Add comments, or if you can mentor, add that information too!
> >
> >Let's get a new faster Data.Map and other containers ready to go by the
> >end of the northern summer?
> 
> Hello Don,
> 
> I'm not sure what you're proposing as the SOC project, but I don't think
> getting AVL based Data.Map/Set clones in Hackage is particularly
> suitable or challenging. This work is 99% done and also quite boring.
> It could be finished by the end of today if I set my mind to it :-)

I was more putting it in as a stub for you to round out to a full SoC 
proposal to work on data structure things.. :)
  
> There are 3 significant things that really need doing IMO.
> 1- Try to reconcile the apparent differences between the collections
>    package and Edison class APIs. I don't really understand either
>    myself, but having multiple classes for "the same" things makes
>    both implementors and test suite writers lives harder.
>    The generalised trie class "GT" should still be kept separate as
>    it needs some weird class methods in order to make new instances
>    from old and can't really be finalised until this type families
>    stuff is available anyway.
> 
> 2- Write a polymorphic test and benchmarking suite for sets, maps,
>    sequences etc. This would be really useful and is something that
>    could reasonably be done as SOC project. But it may also be little
>    boring :-(
>    This could be based on classes defined as a result of 1 (above),
>    or failing that the author would have to define yet another set
>    of class APIs for test/benchmarking only. This may be the simpler
>    approach as it doesn't assume anything about Edison or collections
>    abstractions (it's just a way of testing concrete data structure
>    implementations).
> 
> 3- Produce some way of automatically deriving (efficient) generalised
>    trie (GT) instances for user defined types. The API is huge and
>    complex (and likely to get bigger still), so hand writing instances
>    really isn't realistic in the long run.
>    But this may be a bit premature for SOC as the GT class API itself
>    is not yet complete or stable, and probably won't be until type
>    families are available (and tested and documented and someone
>    takes the trouble to finish it).
>    So maybe this is something for next years SOC?
> 
> That said, I know that type families are provisionally available, so
> maybe doing something with generalised tries might be possible.
> I don't mind mentoring anyone who wants to do something with any of
> this.

Great! Would you like to revise the Soc ticket, with this information?

Getting some usable generalised tries available would be a great
result.

-- Don