Re: Matching labels with buttons

[Stephen Berman <stephen.berman@gmx.net>]

On Mon, 15 Jul 2024 22:29:27 +0000 Heime <heimeborgia@protonmail.com> wrote:

> On Tuesday, July 16th, 2024 at 9:50 AM, Stephen Berman
> <stephen.berman@gmx.net> wrote:
>
>> On Mon, 15 Jul 2024 21:29:38 +0000 Heime heimeborgia@protonmail.com wrote:
>>
>> > On Tuesday, July 16th, 2024 at 9:20 AM, Stephen Berman
>> > stephen.berman@gmx.net wrote:
>> >
>> > > On Mon, 15 Jul 2024 17:25:42 +0000 Heime heimeborgia@protonmail.com wrote:
>> > >
>> > > > On Tuesday, July 16th, 2024 at 4:24 AM, Heime
>> > > > heimeborgia@protonmail.com wrote:
>>
>> [...]
>>
>> > > > > I also have to handle the case of " LABEL [-] " with a different regex,
>> > > > > so I can
>> > > > > distinguish between " [-] LABEL " and " LABEL [-] ".
>> > > >
>> > > > In the latter case I want to match [-] at the end with any trailing spaces.
>> > >
>> > > With your original code amended by anchoring the first regexp as I
>> > > suggested, I think it handles both cases you want; at least the brief
>> > > tests I tried worked. If you don't get the results you want, please
>> > > show the complete code you're using and examples where it fails.
>> > >
>> > > Steve Berman
>> >
>> > Have used
>> >
>> > "\\`\\(\\s-\\[\\-\\]\\s-\\)\\(.*\\)" for " [-] LABEL "
>> >
>> > and
>> >
>> > "\\(.\\)\\(\\s-\\[\\-\\]\\s-*\\)\\'" for " LABEL [-] "
>>
>>
>> Since you didn't do what I requested, I've done it. Evaluate the
>> following code, which is based on your original code amended as I
>> suggested (I didn't use "\\'" in the second regexp, but the results are
>> the same with and without it):
>
> Was that about showing the code ?  It is basically writing down the regex strings.

I asked for the complete code, so I don't have to guess what you're doing.

>> (defun heime-button (label)
>> (if (string-match "\\`\\(\\s-\\[\\-\\]\\s-\\)\\(.\\)" label) ; [-] LB
>> (progn
>> (setq bt (match-string 1 label))
>> (setq lb (match-string 2 label))
>> (setq result
>> (concat bt (propertize lb 'face '(:foreground "red")))))
>> (when (string-match "\\(.\\)\\(\\s-\\[\\-\\]\\s-\\)" label) ; LB [-]
>> (setq lb (match-string 1 label))
>> (setq bt (match-string 2 label))
>> (setq result
>> (concat (propertize lb 'face '(:foreground "red")) bt))))
>> (insert result))
>>
>> (with-current-buffer (get-buffer-create "Heime Test")
>> (erase-buffer)
>> (heime-button " [-] LABEL ")
>> (newline)
>> (heime-button " LABEL [-] "))
>>
>> (switch-to-buffer "Heime Test")
>>
>> What I see in buffer Heime Test is this:
>>
>> [-] LABEL
>> LABEL [-]
>>
>> where each string "LABEL" is red. Is this not what you want?
>>
>> Steve Berman
>
> Yes it is what I wanted.  Having read the documentation, why don't you apply
> \\' for the second case to match the empty string, but only at the end of string
> being matched against ?

As I wrote, for the examples you've given, the results are the same with
and without "\\'" at the end of the second regexp, so omitting it
simplifies the regexp.  But if you want to avoid matching a string like
" LABEL [-] some other text", then you should include the end anchor "\\'".

Steve Berman