Re: To switch state of line not working

[Emanuel Berg via Users list for the GNU Emacs text editor <help-gnu-emacs@gnu.org>]

Jean Louis wrote:

> 1. [ ] Something to do
> 2. [ ] More to do
> 3. [✔] And more
> 4. [✔] Even more.
>
> This function below is supposed to switch from [✔] to [ ] when cursor
> is on the line but it is not working. It is switching only from [ ] to
> [✔].  Does somebody sees why?
>
> (defun rcd-check (&optional check-in check-out)
>   (interactive)
>   (let* ((start (line-beginning-position))
> 	 (end (line-end-position))
> 	 (line (buffer-substring start end))
> 	 (check-in (or check-in (regexp-quote "[ ]")))
> 	 (check-out (or check-out (regexp-quote "[✔]"))))
>     (if (string-match check-in line)
> 	(progn
> 	  (replace-line check-in check-out))
>       (if (string-match check-out line)
> 	  (progn
> 	    (replace-line check-out check-in))))))

name: "start" -> "beg" for nice align with "end".

first `if' - no need for `progn'.

second if - ditto, also here use `when' instead.

> (defun replace-line (from to)
>   (let* ((start (line-beginning-position))
> 	 (end (line-end-position))
> 	 (line (buffer-substring start end)))
>     (save-excursion
>       (replace-string from to nil start end))))

`replace-string' should be `search-forward' and
`replace-match'.

And you are not using "line"!

Also try `buffer-substring-no-properties' if the above
doesn't help.

-- 
underground experts united
https://dataswamp.org/~incal