collections in hierarchical libraries

[Daan Leijen]

> Rencent posts about DData and such make me think...
> Shouldn't it be integrated in the hierarchical
> libraries?

Hi JP,

It would be cool to have it in the hierarchical libraries.
I am thinking about it, but it would probably be best if
it moved to something like Misc.DData instead of Data.DData,
since it a lot the DData stuff is already there as Data.FiniteMap etc.

Secondly, it is relatively easy to just copy the files to your
project and use it there, as they are all stand-alone Haskell modules.

> Besides, it looks like Edison has been dropped from
> GHC.

No one seems to support Edison. However, there is an important
difference between Edison and DData: DData provides implementations
of specific structures, while Edison tried to provide general collection
interfaces *and* implementations. I believe that designing good generic
collection interfaces is very hard and may even be impossible to do "right"
in current Haskell's. So, I guess we will be stuck with concrete
data structures for a while :-)

All the best,
  Daan.