Re: Scan of regexps in Emacs (March 17)

["Mattias Engdegård" <mattiase@acm.org>]

20 mars 2019 kl. 02.53 skrev Paul Eggert <eggert@cs.ucla.edu>:
> 
> Thanks for proofreading that. I installed the attached to try to fix the problems you noted.

That looks fine. You found more skip-chars-* rubbish to clean up, good! Turn any stone...

> I also fixed a couple of other problems if I happened to run across them. First, the regexp [a-b-c] is ambiguous according to POSIX, and should be avoided. Second, a regexp like [[:alnum:]-z] is also ambiguous for the same reason. Perhaps these regexps currently have a particular behavior in Emacs but it's not documented as far as I know and code should avoid them. Perhaps the trawler could be modified to catch them.

Right, the rules are muddy; they had to be reverse-engineered for xr. I was a bit disappointed not to find any [a-[:alnum:]] anywhere though; that would have been a sight.
I'll see what can be done -- it's always a matter of balance to avoid false positives.

By the way, my little diatribe about format arguments led to a mechanised search for argument count violations. One found, in eshell, pushed to master as obvious:

diff --git a/lisp/eshell/esh-proc.el b/lisp/eshell/esh-proc.el
index 55251f5bfb..3432582cf4 100644
--- a/lisp/eshell/esh-proc.el
+++ b/lisp/eshell/esh-proc.el
@@ -498,7 +498,7 @@ See the variable `eshell-kill-processes-on-exit'."
                                        (buffer-name))))
          (eshell-round-robin-kill
           (if (eq eshell-kill-processes-on-exit 'every)
-              (format-message "Kill Eshell child process `%s'? "))))
+              "Kill Eshell child process `%s'? ")))
       (let ((buf (get-buffer "*Process List*")))
        (if (and buf (buffer-live-p buf))
            (kill-buffer buf)))