Re: latexenc-find-file-coding-system is slow.

[David Kastrup <dak@gnu.org>]

Lute Kamstra <Lute.Kamstra.lists@xs4all.nl> writes:

> Thien-Thi Nguyen <ttn@gnu.org> writes:
>
>> Arne Jørgensen <arne@arnested.dk> writes:
>>
>>> Richard Stallman <rms@gnu.org> wrote March 4, 2005:
>>> 
>>> > We can now install them.  Could you send me the
>>> > latest version of your changes, with change log
>>> > entries?
>>> 
>>> So now I'm trying to post to list
>>
>> i have installed the files w/ the suggested names;
>> only modification was to re-indent latexenc.el.
>
> Since this change, opening a 117k .texi file takes seconds.  It used
> to take a fraction of a second.  I did a debug-on-quit during the wait
> a couple of times and that consistently gave me one of these two
> backtraces:
>
> Debugger entered--Lisp error: (quit)
>   re-search-forward("^[^%$]*\\inputencoding{\\(.*\\)}" nil t)
>
> Debugger entered--Lisp error: (quit)
>   re-search-forward("^[^%$]*\\usepackage\\[\\(.*\\)\\]{inputenc}" nil t)
>
> I guess the re-searching in latexenc-find-file-coding-system needs to
> be improved.

It simply needs to get limited: if the string is not in the first 3k
or so, don't look further for it.

However, if a 117k file already takes seconds, this also is a sign
that the regular expressions are faulty (even searching the whole file
should not take seconds at this size).  And it certainly is a bug that
the inverted character range contains $ instead of \n: $ is not
special in the expression.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum