PROPOSAL: More base package breakup

[Ian Lynagh]

Hi all,

This is trac #1338:
    http://hackage.haskell.org/trac/ghc/ticket/1338#comment:14
    http://hackage.haskell.org/trac/ghc/attachment/ticket/1338/packagegraph.png

Initial deadline: 21 Aug (2 weeks).

The base package is still a large, unwieldy beast, making it hard to
develop and debug. If possible, I'd like to cut it down a bit more
before the 6.10 release.

I won't inline all the details here, as it's a huge amount of text and
an image, but basically I'm proposing to:

* Create packages:
    timeout, unique, concurrent,
    st,
    system, numeric, generics,
    version, getopt, debug, printf
    ghc-exts
* Merge what I've listed as "control" into "containers"

There's definitely a "foreign" package fighting to get out too, but that
needs more work before we can set it free.


An important point to note is that Simon Marlow has made a base 3
compatibility library that will come with GHC 6.10, and will provide the
same interface as the base library that came with 6.8, so breaking
backwards compatibility in base 4 shouldn't cause large problems like
the base 2 to base 3 change did.


Thanks
Ian