Re: checking several headers when splitting mail

[Ted Zlatanov <tzz@lifelogs.com>]

On Tue, 28 Jun 2011 20:04:58 +0200 Andreas Schwab <schwab@linux-m68k.org> wrote: 

AS> Ted Zlatanov <tzz@lifelogs.com> writes:
>> On Wed, 15 Jun 2011 22:42:33 +0200 Andreas Schwab <schwab@linux-m68k.org> wrote: 
>> 
AS> You either need to make ?+ a word character in
AS> nnmail-split-fancy-syntax-table, or use ".*\\+491234567".
>> 
>> Could you show an example?

AS> Read the doc string of modify-syntax-entry.

So, for those who are interested, it's useful to test fancy splits like
this:

#+begin_src lisp
(let ((mytable (copy-syntax-table nnmail-split-fancy-syntax-table)))
  (when (with-syntax-table mytable
          (string-match "\\</var/log" "/var/log"))
    (message "Matches without modification"))
  (modify-syntax-entry ?/ "w" mytable)
  (when (with-syntax-table mytable
          (string-match "\\</var/log" "/var/log"))
    (message "Matches with modification")))

#+end_src

Would that be useful in the manual as a demonstration of what a word
character will do?

Now for the next questions: is there any downside to modifying
`nnmail-split-fancy-syntax-table'?  And why does ".*\\+491234567" work?
What exactly are we looking at to match against the regular expression,
in other words, and why does that match when the regular expression is
".*\\+491234567" but not otherwise?

Thanks for your help, as always.
Ted