Re: [AUCTeX-devel] Extending `LaTeX-array-count-columns'

[Mosè Giordano]

Hi Arash,

2016-12-14 12:34 GMT+01:00 Arash Esbati <address@hidden>:
> Hi all,
>
> 2 thing occurred to me when hitting `M-RET' in tabular environments:
> Current code in `LaTeX-array-count-columns' cannot handle multi column
> specs like `*{num}{spec}' and optional args to column specs S and s from
> siunitx.el.  I have a patch to handle both issues.  Can people please
> test this code against their tabular's and see if it does the right
> thing?  My test file is:
>
> --8<---------------cut here---------------start------------->8---
> \documentclass{article}
>
> \usepackage{siunitx}
> \usepackage{array}
> \usepackage{tabularx}
> \newcolumntype{Y}{>{\tiny\scshape}r}
>
> \begin{document}
>
> Eval first:
> \begin{verbatim}
> (defun LaTeX-array-count-columns (start end)
>   "Count number of ampersands to be inserted.
> The columns are specified by the letters found in the string
> `LaTeX-array-column-letters' and the number of those letters within the
> text between START and END is basically considered to be the number of
> columns.  The arguments surrounded between braces such as p{30pt} do not
> interfere the count of columns.
>
> Return one less number than the columns, or nil on failing to count the
> right number."
>   (save-excursion
>     (let (p (cols 0))
>       (goto-char start)
>       (while (< (setq p (point)) end)
>
>         ;; The below block accounts for one unit of move for
>         ;; one column.
>         (setq cols (+ cols
>                       (if (looking-at-p "\\*[ \t\r\n%]*{[ \t\r\n%0-9]+}")
>                           (progn
>                             (re-search-forward
>                              "\\*[ \t\r\n%]*{[ \t\r\n%]*\\([0-9]+\\)[ 
> \t\r\n%]*}" end t)
>                             (string-to-number (match-string-no-properties 1)))
>                         (skip-chars-forward
>                          LaTeX-array-column-letters end))))
>         (skip-chars-forward (concat
>                              "^" LaTeX-array-column-letters "*"
>                              TeX-grop LaTeX-optop) end)
>         (when (or (eq (following-char) ?\{)
>                   (eq (following-char) ?\[))
>           (forward-list 1))
>
>         ;; Not sure whether this is really necessary or not, but
>         ;; prepare for possible infinite loop anyway.
>         (when (eq p (point))
>           (setq cols nil)
>           (goto-char end)))
>       ;; The number of ampersands is one less than column.
>       (if cols (1- cols)))))
> \end{verbatim}
>
> Standard procedure:
> \begin{tabular}[t]{*{4}{l}l}
>   1 & 2 & 3 & 4 & 5 \\
>     &&&&
> \end{tabular}
>
> Add some commands before cells:
> \begin{tabular}[b]{*{4}{>{\scriptsize}l}>{\huge}l}
>   1 & 2 & 3 & 4 & 5 \\
>     &&&&
> \end{tabular}
>
> \begin{tabular}{*{4}{>{\scriptsize}l} |l|}
>   1 & 2 & 3 & 4 & 5 \\
>     &&&&
> \end{tabular}
>
> Custom column spec `Y':
> \begin{tabular}[t]{* { 2 } {>{\scriptsize}l} | Y | * { 2 } {r}}
>   1 & 2 & 3 & 4 & 5 \\
>     &&&&
> \end{tabular}
>
> Eval first for `siunitx.el':
> \begin{verbatim}
> (set (make-local-variable 'LaTeX-array-column-letters)
>      (concat LaTeX-array-column-letters "sS"))
> \end{verbatim}
>
> Ignore optional `[...]' after S and s:
> \begin{tabular}{
>   s
>   S[table-number-alignment = center]
>   s[table-number-alignment = left]
>   S[table-number-alignment = right]
>   }
>   {Some Values} & {Some Values} & {Some Values} & {Some Values} \\
>                 &&&
> \end{tabular}
>
> \begin{tabular}{%
>   S[table-format = 1.1e1]
>   S[fixed-exponent = 3 ,
>     table-format = 2.1 ,
>     table-omit-exponent ] }
>   1 & 2 \\
>     &
> \end{tabular}
> \end{document}
> --8<---------------cut here---------------end--------------->8---
>
> Any comments welcome.

I briefly tested the file, and seems to work nicely, thanks for your work!

As usual, I strongly suggest you to add the appropriate tests for the
new feature.

Bye,
Mosè