(I re-added the list to the CC: I guess you are interested
in getting some help, and I'm not necessarily the best at
this)

On Sat, Jun 17, 2023 at 09:09:37AM -0500, Joshua Lambert wrote:
> On Fri, Jun 16, 2023 at 11:48 PM <tomas@tuxteam.de> wrote:
> >
> > The above means that you are inserting stuff at the beginning of the
> > current line, right?
> 
> Yes. That is correct.

OK.

[...]

> > I.e.: do you need to (save-excursion ...) around `some-chosen-function'?
> > What do you do with its result? That kind of things.
> >
> Sorry I have not sent enough or the correct information. I may not
> need to save the excursion but it is a nice user feature I would like
> to keep.

If you have your "protocol" clear, that's fine :-)

> The function that follows works like I want but is very repetitive
> given what I mention below. In order for me to run various data
> cleanup processes, I exchange the (my-string-pad-concat
> (my-get-string-from-line field-num)) with other function calls. One
> correctly pads a string as needed. (this is internal padding that has
> to follow complicated logic.) Another removes unneeded spaces from
> other strings. So forth. Each of those provides a string to be
> inserted at the beginning of each line.
> 
> (defun my-make-region-sortable (&optional field-num beg end)
>   "Create a padded string for each line in region.
>   Interactively, BEG and END are the region."
>   (interactive "*p\nr")
>   (let ((beg2 (if (region-active-p)
>                          beg
>                       (line-beginning-position)))
>            (end2 (if (region-active-p)
>                            end
>                        (line-end-position))))
>      (save-excursion
>        (save-restriction
>          (narrow-to-region beg2 end2)
>          (goto-char (point-min))
>          (while (not (eobp))
>            (goto-char (line-beginning-position))
>            (insert (my-string-pad-concat (my-get-string-from-line field-num)))
>            (insert string-separator)
>            (forward-line))))))

Hm. So you want to pass an extra arg to call where `my-string-pad-concat ...' is?

Cheers
-- 
t