Gnus range/list makeover

Gnus range/list makeover

[Lars Magne Ingebrigtsen]

Gnus currently uncompresses some ranges when entering groups.  If you
have a group with a lot of (unread) articles, and you just want to see
the last five, it takes several seconds to uncompress the required
ranges.

And it's the same problem with groups that are very sparse, like nnimap
groups with high UIDs.

So I think I'm going to redo all that to keep all the ranges
compressed.  That means replacing oodles of calls to `memq' in gnus-sum
with `gnus-range-memq' and stuff.

The result should be much faster group entry in some situations, but
it's also likely to lead to breakage.  I'm just saying.  :-)

My plan for how to do this is to first rename

(defvar gnus-newsgroup-marked nil)

and the equivalent for about 20 other of these variables to 

(defvar grnus-newsgroup-marked nil)

and then letting the compiler find all the instances of the variables,
and then convert all accesses to range accesses instead of sequence
accesses.

And then rename everything back again.

-- 
(domestic pets only, the antidote for overdose, milk.)
  larsi@gnus.org * Lars Magne Ingebrigtsen