Hi,
On 2021-04-20, 15:40 +0200, Nicolas Goaziou <m...@nicolasgoaziou.fr> wrote:
> For the problem we're trying to solve, this sounds like over-engineering
> to me. Do we want so badly to guess a separator?
Earlier I took is as an assignment to learn Elisp but now I don't think
we should increase complexity this much.
> Thinking again about it, this needs extra care, as end0 might end up on
> an empty line. You tried to avoid this in your first function, but
> I think this was not sufficient either. Actually, beg0 could also start
> on an empty line.
>
> This needs to be tested extensively, but as a first approximation,
> I think `beg' needs to be defined as:
>
> (save-excursion
> (goto-char (min beg0 end0))
> (skip-chars-forward " \t\n")
> (if (eobp) (point) (line-beginning-position)))
>
> and `end' as
>
> (save-excursion
> (goto-char (max beg end0))
> (skip-chars-backward " \t\n" beg)
> (if (= beg (point)) (point) (line-end-position)))
>
> Then you need to bail out if beg = end.
>
>> (sep-rexp '(("," "^[^\n,]+$")
>
> sep-rexp -> sep-regexp
>
>> ("\t" "^[^\n\t]+$")
>> (";" "^[^\n;]+$")
>> (":" "^[^\n:]+$")
>> (" " "^\\([^'\"][^\n\s][^'\"]\\)+$")))
>
> At this point, I suggest to use `rx' macro instead.
>
> I suggest this (yes, I like pattern-matching, `car' and `cdr' are so
> 80's) instead:
>
> (save-excursion
> (goto-char beg)
> (catch :found
> (pcase-dolist (`(,sep ,regexp) sep-regexp)
> (save-excursion
> (unless (re-search-forward regexp end t)
> (throw :found sep))))
> nil))
>
Thanks! I was not aware of pcase-dolist function.
Function after doing the necessary changes:
(defun org-table-guess-separator (beg0 end0)
"Guess separator for `org-table-convert-region' for region BEG0 to END0.
List of preferred separator:
comma, TAB, semicolon, colon or SPACE.
If region contains a line which doesn't contain the required
separator then discard the separator and search again using next
separator."
(let* ((beg (save-excursion
(goto-char (min beg0 end0))
(skip-chars-forward " \t\n")
(if (eobp) (point) (line-beginning-position))))
(end (save-excursion
(goto-char (max beg end0))
(skip-chars-backward " \t\n" beg)
(if (= beg (point)) (point) (line-end-position))))
(sep-regexp '(("," (rx bol (1+ (not (or ?\n ?,))) eol))
("\t" (rx bol (1+ (not (or ?\n ?\t))) eol))
(";" (rx bol (1+ (not (or ?\n ?\;))) eol))
(":" (rx bol (1+ (not (or ?\n ?:))) eol))
(" " (rx bol (1+ (not (or ?' ?\" ))
(not (or ?\s ?\;))
(not (or ?' ?\"))) eol))))
sep)
(unless (= beg end)
(save-excursion
(goto-char beg)
(catch :found
(pcase-dolist (`(,sep ,regexp) sep-regexp)
(save-excursion
(unless (re-search-forward (eval regexp) end t)
(throw :found sep))))
nil)))))
> Again all this needs to extensively tested, as there are a lot of
> dangers lurking around.
Summary of things that still requires a review:
+ Setting boundary right
+ When using SPACE as separator is it sufficient to check for all for
all non quoted SPACE's?
--
Utkarsh Singh
http://utkarshsingh.xyz
