Subject: bug#26010: Indenting in tabulars and \&

From: Arash Esbati <[email-masked]>
Date: Tue, 07 Mar 2017 20:27:46 +0100

Ikumi Keita <[email-masked]> writes:

>> Otherwise, I suggest the following change in `LaTeX-indent-tabular':
>>     (cond (...
>> 	  (t
>> 	   (+ 2
>>               (let ((any-col (save-excursion
>>                                (when (re-search-backward "\\\\\\\\\\|[^\\]&" beg-pos t)
>>                                  (current-column)))))
>>                 (if (and any-col (string= "&" (substring (match-string-no-properties 0) -1)))
>>                     (1+ any-col)
>> 		  beg-col)))))))
>> Comments welcome.

Hi Keita,

many thanks for checking and your response.

> I think the form `(string= ...)' can be replaced with
> `(= ?& (char-before (match-end 0)))'.

Yes, this is even more elegant.

> And here is another solution keeping the regexp untouched:
>     (cond (...
> 	   (t
> 	    (+ 2
> 	       (let ((any-col (save-excursion
> 				(when (and
> 				       (re-search-backward "\\\\\\\\\\|&" beg-pos t)
> 				       (= ?& (char-after))
> 				       (not (TeX-escaped-p)))
> 				  (current-column)))))
> 		 (or any-col
> 		   beg-col))))))))
>
> Using `TeX-escaped-p' might be overkilling since we allow loose usages of
> (looking-at "\\\\\\\\") and (re-search-backward "\\\\\\\\... ) in this
> function.

I agree, this seems overkill.  `[^\\]' is also used in
`LaTeX-hanging-ampersand-position' which is right above
`LaTeX-indent-tabular' in latex. el -- these functions would look more
in line with `[^\\]' in regexp.  This is the current suggestion:

  (cond (...
       (t
        (+ 2
            (let ((any-col (save-excursion
                             (when (re-search-backward "\\\\\\\\\\|[^\\]&" beg-pos t)
                               (current-column)))))
              (if (and any-col (= ?& (char-before (match-end 0)))
                  (1+ any-col)
               beg-col)))))))

Best, Arash