bug#4511: 23.1; flyspell-mode slow editing near end of big html file

[Kevin Ryde <user42@zip.com.au>]

Stefan Monnier <monnier@iro.umontreal.ca> writes:
>
> The given regexp is actually plenty, in this respect.  It's just that
> looking-back is a dog and doesn't make good use of the regexp.

Oh, well, I suppose a genuine reverse matcher could do the right thing,
probably if "<" was added to the exclusions like "<[^<>\n]*" -- not that
that helps since there isn't a reverse matcher :-).


But on the principle "why can't someone else do it", what about letting
`sgml-lexical-context' determine the context.  Tested only briefly:

(defun sgml-mode-flyspell-verify ()
  "Function used for `flyspell-generic-check-word-predicate' in SGML mode."
  (not (memq (car (sgml-lexical-context))
             '(tag pi))))

Seems fast enough for me, and I think it means CDATA text is checked,
which I think would be desirable, but I'm not well up on that stuff.