Re: Slighty improved regexps for citations

[sigurd@12move.de (Karl Pflästerer)]

On Wed, 26 Feb 2003, Maciej Matysiak <- phoner.ding@blah.pl wrote:

> would it be possible to make gnus recongnize ':' as citation prefix,
> but not ':)', ':-)' and other smiley mutations? that'd be prolly quite
> ugly regexp i think, but at the moment i have to remove the colon from
> m-c-p-r (or have hilighted every second line in some mails :( ).

It is possible and the regexp would not be too ugly (well for some
approbiate values of ugly). If we accept that the second char of a
smiley is a dash (if you look at the value of `smiley-regexp-alist'
at the moment that's true).
Then we could write (I rewrote the definition a bit so it is easier to
read):

(setq message-cite-prefix-regexp
	(if (string-match "[[:digit:]]" "1");; support POSIX?
	  (concat
	   "\\("
	   "[ \t]*[-_.[:word:]]+>+\\|"
	   "[ \t]*:+[^-]\\|"
	   "[ \t]*[]>|#}+]"
	   "\\)+")

	  ;; ?-, ?_ or ?. MUST NOT be in syntax entry w.
	  (let ((old-table (syntax-table))
		non-word-constituents)
	    (set-syntax-table text-mode-syntax-table)
	    (setq non-word-constituents
		    (concat
		     (if (string-match "\\w" "-")  "" "-")
		     (if (string-match "\\w" "_")  "" "_")
		     (if (string-match "\\w" ".")  "" ".")))
	    (set-syntax-table old-table)
	    (if (equal non-word-constituents "")
	      (concat
	       "\\("
	       "[ \t]*\\(\\w\\)+>+\\|"
	       "[ \t]*:+[^-]\\|"
	       "[ \t]*[]>|}+]"
	       "\\)+")
	      (concat
	       "\\("
	       "[ \t]*\\(\\w\\|[" non-word-constituents "]\\)+>+\\|"
	       "[ \t]*:+[^-]\\|"
	       "[ \t]*[]>|#}+]"
	       "\\)+")))))

Here a some lines to test if it works:
> should be a citation
> also
: and here
: and there
:- but here not

The best way would be IMO to use the keys of `smiley-regexp-alist'. They
could be retrieved like that:

(let ((smileyreg))
  (dolist (entry smiley-regexp-alist)
    (setq smileyreg (concat smileyreg (and smileyreg "\\|") (car entry))))
  smileyreg)

but the problem is, there are some constructions which are not allowed
in between square brackets.


bye
   KP

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