On Tue, Apr 03 2007, Chong Yidong wrote:

> How about the following approach?  At the beginning of characters.el,
> save the standard case table (which AFAICT hasn't been modified at
> that point), as a variable ascii-case-table.  Then downcase-ascii can
> use it.
[...]
> + (defun downcase-ascii (string)
> +   "Convert ASCII argument to lower case and return that.
> + The argument may be a character or string.  The result has the same type.
> + The argument object is not altered--the value is a copy."
> +   (let ((old-case-table (current-case-table)))
> +     (unwind-protect
> + 	(progn (set-case-table ascii-case-table)
> + 	       (downcase string))
> +       (set-case-table old-case-table))))

Note that the problem is not only the `downcase' function.  So maybe
adding `with-case-table' would be a good idea.

Turkish Gnus user's might still suffer from the "slow search
operations problem" [1] in `gnus/nnfolder.el'.  Based on your previous
patch, I've made a preliminary patch for `nnfolder.el' [2].  I didn't
test it yet (I don't use the nnfolder back end).  It has to be
adjusted to use `ascii-case-table' and some compatibility code for
Emacs 21 (where the downcase problem is not present).

Bye, Reiner.

[1]
,----[ http://thread.gmane.org/gmane.emacs.gnus.general/63925/focus=63979 ]
| From: Reiner Steib
| Subject: Re: Slow operations on buffers of tens of megabytes
| Newsgroups: gmane.emacs.pretest.bugs, gmane.emacs.gnus.general
| Date: 2006-11-13 17:28:58 GMT (19 weeks, 5 days, 3 hours and 34 minutes ago)
| 
| On Thu, Nov 09 2006, Alexandre Oliva wrote:
| 
| > Ultimately, I'm a bit concerned about messing with the case table of
| > an nnfolder buffer for the entire duration of the buffer.  It's hard
| > to tell whether there'd be any less visible fallouts.
| 
| Richard has eliminated the peculiar upcasing dotless-i to I in CVS.
| Does it fix your problem?
| 
| (IIUC, it should fix it _unless_ the user has a Turkish language
| environment.  I.e. Turkish Gnus user's might still suffer from this
| problem.)
| 
| ,----
| | 2006-11-12  Richard Stallman  <rms <at> gnu.org>
| | 
| | 	* language/european.el (turkish-case-conversion-enable)
| | 	(turkish-case-conversion-disable): New functions.
| | 	("Turkish" lang env): Use them.
| | 
| | 	* international/characters.el (case table):
| | 	Do nothing special for i and I.
| `----
`----

[2]