Hi,

I am attaching a possible patch for handling localwords in
flyspell-large-region function. The reason for this is as follows.

I have been using flyspell in a large file having a number of words declared
valid in LocalWords for that file, and running flyspell-buffer is rather
slow, because all mispellings given by 'ispell -l' are checked, even if they
are declared as valid in LocalWords.

I have been playing with a possible way to speed up the process, it
essentially consists on removing valid words (declared in LocalWords) from
the mispellings buffer that contains the 'ispell -l' output *before* they
are checked by regular flyspell means.

That is,

a) Parse buffer being spellchecked and put words in LocalWords in a list.
b) Remove from mispellings buffer lines that match elements of that list.
c) Proceed as usual.

I also needed to remove overlays in the region each time, otherwise when a
word is added to LocalWords and flyspell-buffer run again, it would remain
marked. LocalWords parsing code is stolen from ispell.el.

I already submitted the patch to Manuel Serrano, and has been
incorporated into flyspell-1.7j.el. 

I am attaching the patch as went finally into flyspell-1.7j.el, with a minor
change to apply cleanly to emacs-cvs flyspell.el.

Hope this is useful,

[Please CC me on replies, I am not subscribed to emacs-devel]

Cheers,

-- 
Agustin