Determining existence of text following point

Determining existence of text following point

[michael-franzese]

Is there a way to figure out whether there exist any characters on line
after point.

Re: Determining existence of text following point

[Skip Montanaro]

> Is there a way to figure out whether
> there exist any characters on line
> after point.

Maybe

(looking-at-p ".")

?

Full details on regular expressions searching here

https://www.gnu.org/software/emacs/manual/html_node/elisp/Regexp-Search.html

Skip

Re: Determining existence of text following point

[michael-franzese]

   Would like to delete and insert a string "s" only if there is no text
   folloming point.

   (delete-region (point) (line-end-position))
   (save-excursion (insert s))



   Sent: Tuesday, May 18, 2021 at 10:02 AM
   From: "Skip Montanaro" <skip.montanaro@gmail.com>
   To: michael-franzese@gmx.com
   Cc: "Help Gnu Emacs" <help-gnu-emacs@gnu.org>
   Subject: Re: Determining existence of text following point
   > Is there a way to figure out whether
   > there exist any characters on line
   > after point.

   Maybe

   (looking-at-p ".")

   ?

   Full details on regular expressions searching here

   [1]https://www.gnu.org/software/emacs/manual/html_node/elisp/Regexp-Sea
   rch.html

   Skip

References

   1. https://www.gnu.org/software/emacs/manual/html_node/elisp/Regexp-Search.html

Re: Determining existence of text following point

[Eric Abrahamsen]

michael-franzese@gmx.com writes:

>    Would like to delete and insert a string "s" only if there is no text
>    folloming point.
>
>    (delete-region (point) (line-end-position))
>    (save-excursion (insert s))

There's a function for this: `eolp'

Return t if point is at the end of a line.
‘End of a line’ includes point being at the end of the buffer.

Re: Determining existence of text following point

[michael-franzese]

But if there are only empty spaces it is ok too.

> Sent: Tuesday, May 18, 2021 at 11:05 AM
> From: "Eric Abrahamsen" <eric@ericabrahamsen.net>
> To: michael-franzese@gmx.com
> Cc: "Skip Montanaro" <skip.montanaro@gmail.com>, "Help Gnu Emacs" <help-gnu-emacs@gnu.org>
> Subject: Re: Determining existence of text following point
>
> michael-franzese@gmx.com writes:
> 
> >    Would like to delete and insert a string "s" only if there is no text
> >    folloming point.
> >
> >    (delete-region (point) (line-end-position))
> >    (save-excursion (insert s))
> 
> There's a function for this: `eolp'
> 
> Return t if point is at the end of a line.
> ‘End of a line’ includes point being at the end of the buffer.
>

Re: Determining existence of text following point

[Skip Montanaro]

> But if there are only empty spaces it is ok too.
>

Yes. Spaces between point and the end of the line means point is not at
eol. (Thank you to Eric for the better solution than (looking-at). Been a
while since I actually wrote any significant elisp.)

Skip

>

Re: Determining existence of text following point

[Eric Abrahamsen]

michael-franzese@gmx.com writes:

> But if there are only empty spaces it is ok too.

Ah, then Skip's looking-at is a fine solution:

(looking-at-p "\\([[:blank:]]+\\)?\\(\n\\|\\'\\)")

That's as a test. Or you could use a single `replace-regexp' invocation,
to detect and replace the whitespace in one go.

Re: Determining existence of text following point

[michael-franzese]

> Sent: Tuesday, May 18, 2021 at 12:09 PM
> From: "Eric Abrahamsen" <eric@ericabrahamsen.net>
> To: michael-franzese@gmx.com
> Cc: "Skip Montanaro" <skip.montanaro@gmail.com>, "Help Gnu Emacs" <help-gnu-emacs@gnu.org>
> Subject: Re: Determining existence of text following point
>
> michael-franzese@gmx.com writes:
>
> > But if there are only empty spaces it is ok too.
>
> Ah, then Skip's looking-at is a fine solution:
>
> (looking-at-p "\\([[:blank:]]+\\)?\\(\n\\|\\'\\)")

So this is a condition where I can write my string, because there
are only spaces or a newline after point.


> That's as a test. Or you could use a single `replace-regexp' invocation,
> to detect and replace the whitespace in one go.
>

Re: Determining existence of text following point

[michael-franzese]

Would like to set a function which I could then use with an if statement

Have constructed something as follows.  But naturally the name of the function is
the reverse of having no text (including empty spaces)

(defun looking-at-text ()
  "todo"

    (looking-at-p "\\([[:blank:]]+\\)?\\(\n\\|\\'\\)")

    )

Then my condition for inserting my string would be

(unless (looking-at-text)
   (delete-region (point) (line-end-position))
   (save-excursion (insert s)) )



> Sent: Tuesday, May 18, 2021 at 12:09 PM
> From: "Eric Abrahamsen" <eric@ericabrahamsen.net>
> To: michael-franzese@gmx.com
> Cc: "Skip Montanaro" <skip.montanaro@gmail.com>, "Help Gnu Emacs" <help-gnu-emacs@gnu.org>
> Subject: Re: Determining existence of text following point
>
> michael-franzese@gmx.com writes:
>
> > But if there are only empty spaces it is ok too.
>
> Ah, then Skip's looking-at is a fine solution:
>
> (looking-at-p "\\([[:blank:]]+\\)?\\(\n\\|\\'\\)")
>
> That's as a test. Or you could use a single `replace-regexp' invocation,
> to detect and replace the whitespace in one go.
>

Re: Determining existence of text following point

[Jean Louis]

* Eric Abrahamsen <eric@ericabrahamsen.net> [2021-05-18 03:09]:
> michael-franzese@gmx.com writes:
> 
> > But if there are only empty spaces it is ok too.

(defun my-insert-on-empty-end-of-line (s) 
  (let ((line-cut (buffer-substring-no-properties (point) (line-end-position))))
    (when (or (not (string-match "[^[:blank:]]" line-cut)) (eolp))
      (insert s))))


-- 
Jean

Take action in Free Software Foundation campaigns:
https://www.fsf.org/campaigns

Sign an open letter in support of Richard M. Stallman
https://stallmansupport.org/
https://rms-support-letter.github.io/

Determining existence of text following point

[Christopher Dimech]

> Sent: Tuesday, May 18, 2021 at 8:56 PM
> From: "Jean Louis" <bugs@gnu.support>
> To: "Eric Abrahamsen" <eric@ericabrahamsen.net>
> Cc: "Skip Montanaro" <skip.montanaro@gmail.com>, "Help Gnu Emacs" <help-gnu-emacs@gnu.org>, michael-franzese@gmx.com
> Subject: Re: Determining existence of text following point
>
> * Eric Abrahamsen <eric@ericabrahamsen.net> [2021-05-18 03:09]:
> > michael-franzese@gmx.com writes:
> >
> > > But if there are only empty spaces it is ok too.
>
> (defun my-insert-on-empty-end-of-line (s)
>   (let ((line-cut (buffer-substring-no-properties (point) (line-end-position))))
>     (when (or (not (string-match "[^[:blank:]]" line-cut)) (eolp))
>       (insert s))))

I understand that "string-match" returns index of start of first blank match.

Suppose the cursor is just after the first period.  Then because there is still
text left on the line, the string "s" is not inserted.  The text should only be
inserted when the rest of the line is blank.

A neutrino is a fermion.  Some more text here.
                        ^


> --
> Jean
>
> Take action in Free Software Foundation campaigns:
> https://www.fsf.org/campaigns
>
> Sign an open letter in support of Richard M. Stallman
> https://stallmansupport.org/
> https://rms-support-letter.github.io/
>
>
>

---------------------
Christopher Dimech
General Administrator - Naiad Informatics - GNU Project (Geocomputation)
- Geophysical Simulation
- Geological Subsurface Mapping
- Disaster Preparedness and Mitigation
- Natural Resource Exploration and Production
- Free Software Advocacy

Re: Determining existence of text following point

[Jean Louis]

* Christopher Dimech <dimech@gmx.com> [2021-05-18 12:31]:
> > Sent: Tuesday, May 18, 2021 at 8:56 PM
> > From: "Jean Louis" <bugs@gnu.support>
> > To: "Eric Abrahamsen" <eric@ericabrahamsen.net>
> > Cc: "Skip Montanaro" <skip.montanaro@gmail.com>, "Help Gnu Emacs" <help-gnu-emacs@gnu.org>, michael-franzese@gmx.com
> > Subject: Re: Determining existence of text following point
> >
> > * Eric Abrahamsen <eric@ericabrahamsen.net> [2021-05-18 03:09]:
> > > michael-franzese@gmx.com writes:
> > >
> > > > But if there are only empty spaces it is ok too.
> >
> > (defun my-insert-on-empty-end-of-line (s)
> >   (let ((line-cut (buffer-substring-no-properties (point) (line-end-position))))
> >     (when (or (not (string-match "[^[:blank:]]" line-cut)) (eolp))
> >       (insert s))))
> 
> I understand that "string-match" returns index of start of first blank match.
> 
> Suppose the cursor is just after the first period.  Then because there is still
> text left on the line, the string "s" is not inserted.  The text should only be
> inserted when the rest of the line is blank.

OK, and is it not exactly what that function does?

-- 
Jean

Take action in Free Software Foundation campaigns:
https://www.fsf.org/campaigns

Sign an open letter in support of Richard M. Stallman
https://stallmansupport.org/
https://rms-support-letter.github.io/

Re: Determining existence of text following point

[Jean Louis]

* Christopher Dimech <dimech@gmx.com> [2021-05-18 12:31]:
> > Sent: Tuesday, May 18, 2021 at 8:56 PM
> > From: "Jean Louis" <bugs@gnu.support>
> > To: "Eric Abrahamsen" <eric@ericabrahamsen.net>
> > Cc: "Skip Montanaro" <skip.montanaro@gmail.com>, "Help Gnu Emacs" <help-gnu-emacs@gnu.org>, michael-franzese@gmx.com
> > Subject: Re: Determining existence of text following point
> >
> > * Eric Abrahamsen <eric@ericabrahamsen.net> [2021-05-18 03:09]:
> > > michael-franzese@gmx.com writes:
> > >
> > > > But if there are only empty spaces it is ok too.
> >
> > (defun my-insert-on-empty-end-of-line (s)
> >   (let ((line-cut (buffer-substring-no-properties (point) (line-end-position))))
> >     (when (or (not (string-match "[^[:blank:]]" line-cut)) (eolp))
> >       (insert s))))
> 
> I understand that "string-match" returns index of start of first blank match.
> 
> Suppose the cursor is just after the first period.  Then because there is still
> text left on the line, the string "s" is not inserted.  The text should only be
> inserted when the rest of the line is blank.
> 
> A neutrino is a fermion.  Some more text here.

That (not (string-match "[^[:blank:]]" line-cut)) means it is true if
nothing is found that is not blank space.

Test it here where is the block (remove block):

(string-match "[^[:blank:]]" 
	      (buffer-substring-no-properties (point) (line-end-position)))█   ;; something

(not (string-match "[^[:blank:]]" 
		   (buffer-substring-no-properties (point) (line-end-position))))█   ;; something

(not (string-match "[^[:blank:]]" 
		   (buffer-substring-no-properties (point) (line-end-position))))█ ⇒ t

There is blank space after last parenthesis here, you can test:

(not (string-match "[^[:blank:]]" 
		   (buffer-substring-no-properties (point) (line-end-position))))        

-- 
Jean

Take action in Free Software Foundation campaigns:
https://www.fsf.org/campaigns

Sign an open letter in support of Richard M. Stallman
https://stallmansupport.org/
https://rms-support-letter.github.io/

Re: Determining existence of text following point

[Christopher Dimech]

How is it that the following returns nil?

(setq sa (string-match "[^[:blank:]]" "     "))


> Sent: Tuesday, May 18, 2021 at 9:54 PM
> From: "Jean Louis" <bugs@gnu.support>
> To: "Christopher Dimech" <dimech@gmx.com>
> Cc: "Eric Abrahamsen" <eric@ericabrahamsen.net>, "Skip Montanaro" <skip.montanaro@gmail.com>, "Help Gnu Emacs" <help-gnu-emacs@gnu.org>
> Subject: Re: Determining existence of text following point
>
> * Christopher Dimech <dimech@gmx.com> [2021-05-18 12:31]:
> > > Sent: Tuesday, May 18, 2021 at 8:56 PM
> > > From: "Jean Louis" <bugs@gnu.support>
> > > To: "Eric Abrahamsen" <eric@ericabrahamsen.net>
> > > Cc: "Skip Montanaro" <skip.montanaro@gmail.com>, "Help Gnu Emacs" <help-gnu-emacs@gnu.org>, michael-franzese@gmx.com
> > > Subject: Re: Determining existence of text following point
> > >
> > > * Eric Abrahamsen <eric@ericabrahamsen.net> [2021-05-18 03:09]:
> > > > michael-franzese@gmx.com writes:
> > > >
> > > > > But if there are only empty spaces it is ok too.
> > >
> > > (defun my-insert-on-empty-end-of-line (s)
> > >   (let ((line-cut (buffer-substring-no-properties (point) (line-end-position))))
> > >     (when (or (not (string-match "[^[:blank:]]" line-cut)) (eolp))
> > >       (insert s))))
> > 
> > I understand that "string-match" returns index of start of first blank match.
> > 
> > Suppose the cursor is just after the first period.  Then because there is still
> > text left on the line, the string "s" is not inserted.  The text should only be
> > inserted when the rest of the line is blank.
> > 
> > A neutrino is a fermion.  Some more text here.
> 
> That (not (string-match "[^[:blank:]]" line-cut)) means it is true if
> nothing is found that is not blank space.
> 
> Test it here where is the block (remove block):
> 
> (string-match "[^[:blank:]]" 
> 	      (buffer-substring-no-properties (point) (line-end-position)))█   ;; something
> 
> (not (string-match "[^[:blank:]]" 
> 		   (buffer-substring-no-properties (point) (line-end-position))))█   ;; something
> 
> (not (string-match "[^[:blank:]]" 
> 		   (buffer-substring-no-properties (point) (line-end-position))))█ ⇒ t
> 
> There is blank space after last parenthesis here, you can test:
> 
> (not (string-match "[^[:blank:]]" 
> 		   (buffer-substring-no-properties (point) (line-end-position))))        
> 
> -- 
> Jean
> 
> Take action in Free Software Foundation campaigns:
> https://www.fsf.org/campaigns
> 
> Sign an open letter in support of Richard M. Stallman
> https://stallmansupport.org/
> https://rms-support-letter.github.io/
> 
>

Re: Determining existence of text following point

[tomas]

[-- Attachment #1: Type: text/plain, Size: 287 bytes --]

On Tue, May 18, 2021 at 12:08:42PM +0200, Christopher Dimech wrote:
> How is it that the following returns nil?
> 
> (setq sa (string-match "[^[:blank:]]" "     "))

Because you stated to match any non-blank character and there
are only blank characters to match.

Cheers
 - t

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 198 bytes --]

Re: Determining existence of text following point

[Christopher Dimech]

---------------------
Christopher Dimech
General Administrator - Naiad Informatics - GNU Project (Geocomputation)
- Geophysical Simulation
- Geological Subsurface Mapping
- Disaster Preparedness and Mitigation
- Natural Resource Exploration and Production
- Free Software Advocacy


> Sent: Tuesday, May 18, 2021 at 11:07 PM
> From: tomas@tuxteam.de
> To: help-gnu-emacs@gnu.org
> Subject: Re: Determining existence of text following point
>
> On Tue, May 18, 2021 at 12:08:42PM +0200, Christopher Dimech wrote:
> > How is it that the following returns nil?
> >
> > (setq sa (string-match "[^[:blank:]]" "     "))
>
> Because you stated to match any non-blank character and there
> are only blank characters to match.

The docstring for string-match is

"Return index of start of first match for REGEXP in STRING, or nil."

I find the description different from what string-match actually returns.

> Cheers
>  - t
>

Re: Determining existence of text following point

[Jean Louis]

* Christopher Dimech <dimech@gmx.com> [2021-05-18 14:27]:
> > > (setq sa (string-match "[^[:blank:]]" "     "))

> I find the description different from what string-match actually
> returns.

The symbol ^ means "not following", and that regular expression means
match non-blanks.

(string-match "[^[:blank:]]" "     ") ⇒ nil
(string-match "[[:blank:]]" "     ") ⇒ 0

-- 
Jean

Take action in Free Software Foundation campaigns:
https://www.fsf.org/campaigns

Sign an open letter in support of Richard M. Stallman
https://stallmansupport.org/
https://rms-support-letter.github.io/

Re: Determining existence of text following point

[Christopher Dimech]

> Sent: Tuesday, May 18, 2021 at 11:56 PM
> From: "Jean Louis" <bugs@gnu.support>
> To: "Christopher Dimech" <dimech@gmx.com>
> Cc: tomas@tuxteam.de, help-gnu-emacs@gnu.org
> Subject: Re: Determining existence of text following point
>
> * Christopher Dimech <dimech@gmx.com> [2021-05-18 14:27]:
> > > > (setq sa (string-match "[^[:blank:]]" "     "))
> 
> > I find the description different from what string-match actually
> > returns.
> 
> The symbol ^ means "not following", and that regular expression means
> match non-blanks.
> 
> (string-match "[^[:blank:]]" "     ") ⇒ nil
> (string-match "[[:blank:]]" "     ") ⇒ 0

You are correct.  "^" means match everything but the following class.

I am quite used on see "^" to mean "beginning of line".  So just read
it as I usually do.

It is unfortunate that there exist so many different syntaxes for writing
regular expressions.

> -- 
> Jean
> 
> Take action in Free Software Foundation campaigns:
> https://www.fsf.org/campaigns
> 
> Sign an open letter in support of Richard M. Stallman
> https://stallmansupport.org/
> https://rms-support-letter.github.io/
> 
>

Re: Determining existence of text following point

[tomas]

[-- Attachment #1: Type: text/plain, Size: 1734 bytes --]

On Tue, May 18, 2021 at 02:23:25PM +0200, Christopher Dimech wrote:
> > Sent: Tuesday, May 18, 2021 at 11:56 PM
> > From: "Jean Louis" <bugs@gnu.support>
> > To: "Christopher Dimech" <dimech@gmx.com>
> > Cc: tomas@tuxteam.de, help-gnu-emacs@gnu.org
> > Subject: Re: Determining existence of text following point
> >
> > * Christopher Dimech <dimech@gmx.com> [2021-05-18 14:27]:
> > > > > (setq sa (string-match "[^[:blank:]]" "     "))
> > 
> > > I find the description different from what string-match actually
> > > returns.
> > 
> > The symbol ^ means "not following", and that regular expression means
> > match non-blanks.
> > 
> > (string-match "[^[:blank:]]" "     ") ⇒ nil
> > (string-match "[[:blank:]]" "     ") ⇒ 0
> 
> You are correct.  "^" means match everything but the following class.
> 
> I am quite used on see "^" to mean "beginning of line".  So just read
> it as I usually do.

This is outside the context of character classes, i.e. outside [...].

> It is unfortunate that there exist so many different syntaxes for writing
> regular expressions.

Yet all those syntaxes coincide in that one thing: "^" outside of
brackets means "anchor at the beginning" (of line, most of the time,
but it could be "of string" or similar), whereas inside of character
class brackets (but _only_ right after the opening bracket!) it
means complement.

This is an unfortunate quirk, but those notations are around since
the early 1970s, so that ship has sailed. Go and tell a phisicist
to use something else than the "uppercase L" for the Lagrangian.

The multitude of regular expression extensions and implementations
is an issue, yes, but a completely different one.

Cheers
 - t

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 198 bytes --]

Re: Determining existence of text following point

[Christopher Dimech]

> Sent: Wednesday, May 19, 2021 at 12:35 AM
> From: tomas@tuxteam.de
> To: "Christopher Dimech" <dimech@gmx.com>
> Cc: "Jean Louis" <bugs@gnu.support>, help-gnu-emacs@gnu.org
> Subject: Re: Determining existence of text following point
>
> On Tue, May 18, 2021 at 02:23:25PM +0200, Christopher Dimech wrote:
> > > Sent: Tuesday, May 18, 2021 at 11:56 PM
> > > From: "Jean Louis" <bugs@gnu.support>
> > > To: "Christopher Dimech" <dimech@gmx.com>
> > > Cc: tomas@tuxteam.de, help-gnu-emacs@gnu.org
> > > Subject: Re: Determining existence of text following point
> > >
> > > * Christopher Dimech <dimech@gmx.com> [2021-05-18 14:27]:
> > > > > > (setq sa (string-match "[^[:blank:]]" "     "))
> > > 
> > > > I find the description different from what string-match actually
> > > > returns.
> > > 
> > > The symbol ^ means "not following", and that regular expression means
> > > match non-blanks.
> > > 
> > > (string-match "[^[:blank:]]" "     ") ⇒ nil
> > > (string-match "[[:blank:]]" "     ") ⇒ 0
> > 
> > You are correct.  "^" means match everything but the following class.
> > 
> > I am quite used on see "^" to mean "beginning of line".  So just read
> > it as I usually do.
> 
> This is outside the context of character classes, i.e. outside [...].
> 
> > It is unfortunate that there exist so many different syntaxes for writing
> > regular expressions.
> 
> Yet all those syntaxes coincide in that one thing: "^" outside of
> brackets means "anchor at the beginning" (of line, most of the time,
> but it could be "of string" or similar), whereas inside of character
> class brackets (but _only_ right after the opening bracket!) it
> means complement.
> 
> This is an unfortunate quirk, but those notations are around since
> the early 1970s, so that ship has sailed. Go and tell a phisicist
> to use something else than the "uppercase L" for the Lagrangian.

Richard Feynman used to come up with very strange notation, and we relied on
Freeman Dyson to make sense in a familiar mathematical notation.  Einstein
had the same problem.
 
> The multitude of regular expression extensions and implementations
> is an issue, yes, but a completely different one.
> 
> Cheers
>  - t
>

Re: Determining existence of text following point

[tomas]

[-- Attachment #1: Type: text/plain, Size: 596 bytes --]

On Tue, May 18, 2021 at 01:26:12PM +0200, Christopher Dimech wrote:

[...]

> > On Tue, May 18, 2021 at 12:08:42PM +0200, Christopher Dimech wrote:
> > > How is it that the following returns nil?
> > >
> > > (setq sa (string-match "[^[:blank:]]" "     "))
> >
> > Because you stated to match any non-blank character and there
> > are only blank characters to match.
> 
> The docstring for string-match is
> 
> "Return index of start of first match for REGEXP in STRING, or nil."
> 
> I find the description different from what string-match actually returns.

?

Cheers
 - t

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 198 bytes --]

Re: Determining existence of text following point

[Christopher Dimech]

> Sent: Wednesday, May 19, 2021 at 12:02 AM
> From: tomas@tuxteam.de
> To: "Christopher Dimech" <dimech@gmx.com>
> Cc: help-gnu-emacs@gnu.org
> Subject: Re: Determining existence of text following point
>
> On Tue, May 18, 2021 at 01:26:12PM +0200, Christopher Dimech wrote:
>
> [...]
>
> > > On Tue, May 18, 2021 at 12:08:42PM +0200, Christopher Dimech wrote:
> > > > How is it that the following returns nil?
> > > >
> > > > (setq sa (string-match "[^[:blank:]]" "     "))
> > >
> > > Because you stated to match any non-blank character and there
> > > are only blank characters to match.
> >
> > The docstring for string-match is
> >
> > "Return index of start of first match for REGEXP in STRING, or nil."
> >
> > I find the description different from what string-match actually returns.
>
> ?

string-match looks as though it returns the index of the last match because

(setq sa (string-match "[^[:blank:]]" "  A neutrino is a fermion"))
(setq sb (not (string-match "[^[:blank:]]" "  A neutrino is a fermion")))

gives

sa: 2
sb: nil


> Cheers
>  - t
>

Re: Determining existence of text following point

[tomas]

[-- Attachment #1: Type: text/plain, Size: 937 bytes --]

On Tue, May 18, 2021 at 02:15:27PM +0200, Christopher Dimech wrote:

[...]

> string-match looks as though it returns the index of the last match because
> 
> (setq sa (string-match "[^[:blank:]]" "  A neutrino is a fermion"))
> (setq sb (not (string-match "[^[:blank:]]" "  A neutrino is a fermion")))
> 
> gives
> 
> sa: 2
> sb: nil

Sorry. I still don't understand.

 - You send string-match to find a non-blank character
   It does find one. If you don't specify more, that
   will be the first one, i.e. the "A".

 - Thus the value is 2. This is your first result.

 - You negate that in your second setup (not ...). By
   convention, in Lisp, 'nil' is the false value, everything
   else is considered 'true'. Thus, (not (...)) evaluates
   to (not 2) evaluates to nil. This is your second result.

Now what /is/ your problem? Your posts are sometimes... inscrutable
(to me, at least).

Cheers
 - t

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 198 bytes --]

Re: Determining existence of text following point

[Christopher Dimech]

> Sent: Wednesday, May 19, 2021 at 12:27 AM
> From: tomas@tuxteam.de
> To: "Christopher Dimech" <dimech@gmx.com>
> Cc: help-gnu-emacs@gnu.org
> Subject: Re: Determining existence of text following point
>
> On Tue, May 18, 2021 at 02:15:27PM +0200, Christopher Dimech wrote:
>
> [...]
>
> > string-match looks as though it returns the index of the last match because
> >
> > (setq sa (string-match "[^[:blank:]]" "  A neutrino is a fermion"))
> > (setq sb (not (string-match "[^[:blank:]]" "  A neutrino is a fermion")))
> >
> > gives
> >
> > sa: 2
> > sb: nil
>
> Sorry. I still don't understand.
>
>  - You send string-match to find a non-blank character
>    It does find one. If you don't specify more, that
>    will be the first one, i.e. the "A".
>
>  - Thus the value is 2. This is your first result.
>
>  - You negate that in your second setup (not ...). By
>    convention, in Lisp, 'nil' is the false value, everything
>    else is considered 'true'. Thus, (not (...)) evaluates
>    to (not 2) evaluates to nil. This is your second result.
>
> Now what /is/ your problem? Your posts are sometimes... inscrutable
> (to me, at least).

There is no problem, had misinterpreted "^" to mean beginning of line.
Thusly, everything seemed to be the other way round.


> Cheers
>  - t
>

Re: Determining existence of text following point

[Jean Louis]

(setq sa (string-match "[^[:blank:]]" "  A neutrino is a fermion")) ⇒ 2

The above is because it is matching anywhere anything that is not
blank. If there is only blank character alternative it will not
match. It will be true if there is anything non-blank.

Manual section: (info "(elisp) Regexp Special")

‘[^ ... ]’
     ‘[^’ begins a “complemented character alternative”.  This matches
     any character except the ones specified.  Thus, ‘[^a-z0-9A-Z]’
     matches all characters _except_ ASCII letters and digits.

(setq sb (not (string-match "[^[:blank:]]" "  A neutrino is a fermion"))) ⇒ nil

The `not' will yield TRUE if there is blank only in the string. 

What I find really good is that blank is not just space as we know it,
it will recognize other space types as well.

It will work with:   EN SPACE
(string-match "[^[:blank:]]" " ") ⇒ nil

It will work with: EM SPACE
(string-match "[^[:blank:]]" " ") ⇒ nil

It will work with: THIN SPACE
(string-match "[^[:blank:]]" " ") ⇒ nil

It will work with: HAIR SPAICE
(string-match "[^[:blank:]]" " ") ⇒ nil

It will work with: FIGURE SPACE
(string-match "[^[:blank:]]" " ") ⇒ nil

It will work with: NO BREAK SPACE
(string-match "[^[:blank:]]" " ") ⇒ nil

It will work with: OGHAM SPACE MARK
(string-match "[^[:blank:]]" " ") ⇒ nil

And I guess with other possible spaces. 


-- 
Jean

Take action in Free Software Foundation campaigns:
https://www.fsf.org/campaigns

Sign an open letter in support of Richard M. Stallman
https://stallmansupport.org/
https://rms-support-letter.github.io/

Re: Determining existence of text following point

[Christopher Dimech]

Had not realised that "^" meant "not following".  Interpreted as meaning
"beginning of line".

> Sent: Wednesday, May 19, 2021 at 12:02 AM
> From: tomas@tuxteam.de
> To: "Christopher Dimech" <dimech@gmx.com>
> Cc: help-gnu-emacs@gnu.org
> Subject: Re: Determining existence of text following point
>
> On Tue, May 18, 2021 at 01:26:12PM +0200, Christopher Dimech wrote:
>
> [...]
>
> > > On Tue, May 18, 2021 at 12:08:42PM +0200, Christopher Dimech wrote:
> > > > How is it that the following returns nil?
> > > >
> > > > (setq sa (string-match "[^[:blank:]]" "     "))
> > >
> > > Because you stated to match any non-blank character and there
> > > are only blank characters to match.
> >
> > The docstring for string-match is
> >
> > "Return index of start of first match for REGEXP in STRING, or nil."
> >
> > I find the description different from what string-match actually returns.
>
> ?
>
> Cheers
>  - t
>

Re: Determining existence of text following point

[Jean Louis]

* Christopher Dimech <dimech@gmx.com> [2021-05-18 15:32]:
> Had not realised that "^" meant "not following".  Interpreted as meaning
> "beginning of line".

It depends of the context. (info "(elisp) Regexp Special")

There can be context where it means beginning of line. 

-- 
Jean

Take action in Free Software Foundation campaigns:
https://www.fsf.org/campaigns

Sign an open letter in support of Richard M. Stallman
https://stallmansupport.org/
https://rms-support-letter.github.io/

Re: Determining existence of text following point

[michael-franzese]

> Sent: Tuesday, May 18, 2021 at 8:56 PM
> From: "Jean Louis" <bugs@gnu.support>
> To: "Eric Abrahamsen" <eric@ericabrahamsen.net>
> Cc: "Skip Montanaro" <skip.montanaro@gmail.com>, "Help Gnu Emacs" <help-gnu-emacs@gnu.org>, michael-franzese@gmx.com
> Subject: Re: Determining existence of text following point
>
> * Eric Abrahamsen <eric@ericabrahamsen.net> [2021-05-18 03:09]:
> > michael-franzese@gmx.com writes:
> >
> > > But if there are only empty spaces it is ok too.
>
> (defun my-insert-on-empty-end-of-line (s)
>   (let ((line-cut (buffer-substring-no-properties (point) (line-end-position))))
>     (when (or (not (string-match "[^[:blank:]]" line-cut)) (eolp))
>       (insert s))))

Found out that I would need to extend this some more because if the text is ";;"
followed by space followed by either a series of ";" or "+", or "-", then the
insertion is allowed.  So not just only blanks.

For instance, if the text in a commented string as follows, I will go ahead with
the insertion.

;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;; ++++++++++++++++++++++++++++++++++

;; -------------------------------




>
> --
> Jean
>
> Take action in Free Software Foundation campaigns:
> https://www.fsf.org/campaigns
>
> Sign an open letter in support of Richard M. Stallman
> https://stallmansupport.org/
> https://rms-support-letter.github.io/
>
>
>

Re: Determining existence of text following point

[Jean Louis]

* michael-franzese@gmx.com <michael-franzese@gmx.com> [2021-05-18 23:51]:
> For instance, if the text in a commented string as follows, I will go ahead with
> the insertion.
> 
> ;; ;;;;;;;;;;;;;;█;;;;;;;;;;;;;;;;;;;;;;;;
> 
> ;; +++++++++++++█+++++++++++++++++++++
> 
> ;; ------------█-------------------

You want to be able to insert it there where there are those blocks?



-- 
Jean

Take action in Free Software Foundation campaigns:
https://www.fsf.org/campaigns

Sign an open letter in support of Richard M. Stallman
https://stallmansupport.org/
https://rms-support-letter.github.io/

Re: Determining existence of text following point

[Jean Louis]

* michael-franzese@gmx.com <michael-franzese@gmx.com> [2021-05-18 23:52]:
> For instance, if the text in a commented string as follows, I will go ahead with
> the insertion.
> 
(defun my-insert-on-empty-end-of-line (s)
  (let ((line-cut (buffer-substring-no-properties (point) (line-end-position))))
    (when (or (not (string-match "[^[:blank:]]" line-cut)) (eolp))
      (insert s))))

(defun my-insert-on-empty-end-of-line (s)
  (let ((line-cut (buffer-substring-no-properties (point) (line-end-position))))
    (when (or (not (string-match "[^+[:blank:];-]" line-cut)) (eolp))
      (insert s))))

(defun my-insert ()
  (interactive)
  (my-insert-on-empty-end-of-line "Hello"))

(local-set-key (kbd "<f5>") 'my-insert)

Line with blanks, works:
;;          Hello                              

Line with something else but our series of chars (does not work, expected):

;;       █               abc

Line with fancy stuff that we wish to include (works):

;; ;;;;;;;;;;;;;;;;Hello;;;;;;;;;;;;;;;;;;;;;;
;; +++++++++++++++++++++Hello+++++++++++++
;; -------------------------Hello------Hello

Weird other lines (it does not work, as it is so expected):

;; 𝓒𝓾𝓻𝓼𝓸𝓻 𝓲𝓼 𝓱𝓮𝓻𝓮: █  𝓫𝓾𝓽 𝓲𝓼 𝓷𝓸𝓽 𝔀𝓸𝓻𝓴𝓲𝓷𝓰, 𝐄𝐗𝐏𝐄𝐂𝐓𝐄𝐃!


-- 
Jean

Take action in Free Software Foundation campaigns:
https://www.fsf.org/campaigns

Sign an open letter in support of Richard M. Stallman
https://stallmansupport.org/
https://rms-support-letter.github.io/

Re: Determining existence of text following point

[michael-franzese]

Point will always be at the beginning of a comment on a separate line

The "^" shows the position of the cursor.

                   ^;; ;;;;;;;;;;;;;;;;;;;;;;;;;;

         ^;; +++++++++++++++++++++++++++

^;; ----------------------------

I want to have a keybinding that if I continue to hit will change
a comment from

;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

to

;; +++++++++++++++++++++++++++++++++++++

Currently I have the following code


(defun insert-bifurcation (s n)
   "todo"

   (let* ( (a (point))  (b (line-end-position))
	   (line-cut (buffer-substring-no-properties a b)) )

      (when (or (not (string-match
		        "[^[:blank:]]" line-cut)) (eolp))
         (pcase n

	    (0
  	        (save-excursion (insert s))
	        (comment-region a b))
	    
    	    ((or 1 2 3 4 5)
	        (delete-region a b)
	        (save-excursion (insert s))
		(comment-region a b))

            (_
	        (delete-region a b))) )) )

(defvar count 1)

(defun insert-bifurcating-comment ()
  "Insert bifurcating line at cursor position"
  (interactive)

  (let* ( (m 62) (n 69)
	  (lena (- m (current-column)))   ; lena = m - (current-column)
	  (lenb (- n (current-column))) )

    (pcase count
      (0
         ;; makes s to be line with repeating ";"
         (setq-local s (make-string lena ?\;))  ; repeats lena times
	 (insert-bifurcation s count)
         (setq-local count 1))
      (1
         ;; makes s to be line with repeating ";"
         (setq-local s (make-string lenb ?\;))  ; string length lenb
	 (insert-bifurcation s count)
	 (setq-local count 2))
      (2
         ;; makes s to be line with repeating "+"
         (setq-local s (make-string lena ?+))
	 (insert-bifurcation s count)
         (setq-local count 3))
      (_
         ;; deactivates the bifurcating line
         (insert-bifurcation s count)
         (setq-local count 1)) )) )






> Sent: Wednesday, May 19, 2021 at 10:17 AM
> From: "Jean Louis" <bugs@gnu.support>
> To: michael-franzese@gmx.com
> Cc: "Eric Abrahamsen" <eric@ericabrahamsen.net>, "Skip Montanaro" <skip.montanaro@gmail.com>, "Help Gnu Emacs" <help-gnu-emacs@gnu.org>
> Subject: Re: Determining existence of text following point
>
> * michael-franzese@gmx.com <michael-franzese@gmx.com> [2021-05-18 23:52]:
> > For instance, if the text in a commented string as follows, I will go ahead with
> > the insertion.
> > 
> (defun my-insert-on-empty-end-of-line (s)
>   (let ((line-cut (buffer-substring-no-properties (point) (line-end-position))))
>     (when (or (not (string-match "[^[:blank:]]" line-cut)) (eolp))
>       (insert s))))
> 
> (defun my-insert-on-empty-end-of-line (s)
>   (let ((line-cut (buffer-substring-no-properties (point) (line-end-position))))
>     (when (or (not (string-match "[^+[:blank:];-]" line-cut)) (eolp))
>       (insert s))))
> 
> (defun my-insert ()
>   (interactive)
>   (my-insert-on-empty-end-of-line "Hello"))
> 
> (local-set-key (kbd "<f5>") 'my-insert)
> 
> Line with blanks, works:
> ;;          Hello                              
> 
> Line with something else but our series of chars (does not work, expected):
> 
> ;;       █               abc
> 
> Line with fancy stuff that we wish to include (works):
> 
> ;; ;;;;;;;;;;;;;;;;Hello;;;;;;;;;;;;;;;;;;;;;;
> ;; +++++++++++++++++++++Hello+++++++++++++
> ;; -------------------------Hello------Hello
> 
> Weird other lines (it does not work, as it is so expected):
> 
> ;; 𝓒𝓾𝓻𝓼𝓸𝓻 𝓲𝓼 𝓱𝓮𝓻𝓮: █  𝓫𝓾𝓽 𝓲𝓼 𝓷𝓸𝓽 𝔀𝓸𝓻𝓴𝓲𝓷𝓰, 𝐄𝐗𝐏𝐄𝐂𝐓𝐄𝐃!
> 
> 
> -- 
> Jean
> 
> Take action in Free Software Foundation campaigns:
> https://www.fsf.org/campaigns
> 
> Sign an open letter in support of Richard M. Stallman
> https://stallmansupport.org/
> https://rms-support-letter.github.io/
> 
> 
>

Re: Determining existence of text following point

[michael-franzese]

Have made some simplifications to the code.  I would also like
to handle the following case.

;; ..........................................




> Sent: Wednesday, May 19, 2021 at 7:28 PM
> From: michael-franzese@gmx.com
> To: "Jean Louis" <bugs@gnu.support>
> Cc: "Eric Abrahamsen" <eric@ericabrahamsen.net>, "Skip Montanaro" <skip.montanaro@gmail.com>, "Help Gnu Emacs" <help-gnu-emacs@gnu.org>
> Subject: Re: Determining existence of text following point
>
> Point will always be at the beginning of a comment on a separate line
> 
> The "^" shows the position of the cursor.
> 
>                    ^;; ;;;;;;;;;;;;;;;;;;;;;;;;;;
> 
>          ^;; +++++++++++++++++++++++++++
> 
> ^;; ----------------------------
> 
> I want to have a keybinding that if I continue to hit will change
> a comment from
> 
> ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
> 
> to
> 
> ;; +++++++++++++++++++++++++++++++++++++
> 
> Currently I have the following code
> 
> 
> (defun insert-bifurcation (s n)
>    "todo"
> 
>    (let* ( (a (point))  (b (line-end-position))
> 	   (line-cut (buffer-substring-no-properties a b)) )
> 
>       (when (or (not (string-match
> 		        "[^[:blank:]]" line-cut)) (eolp))
>          (pcase n
> 
> 	    (0
>   	        (save-excursion (insert s))
> 	        (comment-region a b))
> 	    
>     	    ((or 1 2 3 4 5)
> 	        (delete-region a b)
> 	        (save-excursion (insert s))
> 		(comment-region a b))
> 
>             (_
> 	        (delete-region a b))) )) )
> 
> (defvar count 1)
> 
> (defun insert-bifurcating-comment ()
>   "Insert bifurcating line at cursor position"
>   (interactive)
> 
>   (let* ( (m 62) (n 69)
> 	  (lena (- m (current-column)))   ; lena = m - (current-column)
> 	  (lenb (- n (current-column))) )
> 
>     (pcase count
>       (0
>          ;; makes s to be line with repeating ";"
>          (setq-local s (make-string lena ?\;))  ; repeats lena times
> 	 (insert-bifurcation s count)
>          (setq-local count 1))
>       (1
>          ;; makes s to be line with repeating ";"
>          (setq-local s (make-string lenb ?\;))  ; string length lenb
> 	 (insert-bifurcation s count)
> 	 (setq-local count 2))
>       (2
>          ;; makes s to be line with repeating "+"
>          (setq-local s (make-string lena ?+))
> 	 (insert-bifurcation s count)
>          (setq-local count 3))
>       (_
>          ;; deactivates the bifurcating line
>          (insert-bifurcation s count)
>          (setq-local count 1)) )) )
> 
> 
> 
> 
> 
> 
> > Sent: Wednesday, May 19, 2021 at 10:17 AM
> > From: "Jean Louis" <bugs@gnu.support>
> > To: michael-franzese@gmx.com
> > Cc: "Eric Abrahamsen" <eric@ericabrahamsen.net>, "Skip Montanaro" <skip.montanaro@gmail.com>, "Help Gnu Emacs" <help-gnu-emacs@gnu.org>
> > Subject: Re: Determining existence of text following point
> >
> > * michael-franzese@gmx.com <michael-franzese@gmx.com> [2021-05-18 23:52]:
> > > For instance, if the text in a commented string as follows, I will go ahead with
> > > the insertion.
> > > 
> > (defun my-insert-on-empty-end-of-line (s)
> >   (let ((line-cut (buffer-substring-no-properties (point) (line-end-position))))
> >     (when (or (not (string-match "[^[:blank:]]" line-cut)) (eolp))
> >       (insert s))))
> > 
> > (defun my-insert-on-empty-end-of-line (s)
> >   (let ((line-cut (buffer-substring-no-properties (point) (line-end-position))))
> >     (when (or (not (string-match "[^+[:blank:];-]" line-cut)) (eolp))
> >       (insert s))))
> > 
> > (defun my-insert ()
> >   (interactive)
> >   (my-insert-on-empty-end-of-line "Hello"))
> > 
> > (local-set-key (kbd "<f5>") 'my-insert)
> > 
> > Line with blanks, works:
> > ;;          Hello                              
> > 
> > Line with something else but our series of chars (does not work, expected):
> > 
> > ;;       █               abc
> > 
> > Line with fancy stuff that we wish to include (works):
> > 
> > ;; ;;;;;;;;;;;;;;;;Hello;;;;;;;;;;;;;;;;;;;;;;
> > ;; +++++++++++++++++++++Hello+++++++++++++
> > ;; -------------------------Hello------Hello
> > 
> > Weird other lines (it does not work, as it is so expected):
> > 
> > ;; 𝓒𝓾𝓻𝓼𝓸𝓻 𝓲𝓼 𝓱𝓮𝓻𝓮: █  𝓫𝓾𝓽 𝓲𝓼 𝓷𝓸𝓽 𝔀𝓸𝓻𝓴𝓲𝓷𝓰, 𝐄𝐗𝐏𝐄𝐂𝐓𝐄𝐃!
> > 
> > 
> > -- 
> > Jean
> > 
> > Take action in Free Software Foundation campaigns:
> > https://www.fsf.org/campaigns
> > 
> > Sign an open letter in support of Richard M. Stallman
> > https://stallmansupport.org/
> > https://rms-support-letter.github.io/
> > 
> > 
> >
> 
>

Re: Determining existence of text following point

[Jean Louis]

* michael-franzese@gmx.com <michael-franzese@gmx.com> [2021-05-19 10:29]:
> Point will always be at the beginning of a comment on a separate line
> 
> The "^" shows the position of the cursor.
> 
>                    ^;; ;;;;;;;;;;;;;;;;;;;;;;;;;;
> 
>          ^;; +++++++++++++++++++++++++++
> 
> ^;; ----------------------------
> 
> I want to have a keybinding that if I continue to hit will change
> a comment from
> 
> ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
> 
> to
> 
> ;; +++++++++++++++++++++++++++++++++++++
> 
> Currently I have the following code
> 
> 
> (defun insert-bifurcation (s n)
>    "todo"
> 
>    (let* ( (a (point))  (b (line-end-position))
> 	   (line-cut (buffer-substring-no-properties a b)) )
> 
>       (when (or (not (string-match
> 		        "[^[:blank:]]" line-cut)) (eolp))
>          (pcase n
> 
> 	    (0
>   	        (save-excursion (insert s))
> 	        (comment-region a b))
> 	    
>     	    ((or 1 2 3 4 5)
> 	        (delete-region a b)
> 	        (save-excursion (insert s))
> 		(comment-region a b))
> 
>             (_
> 	        (delete-region a b))) )) )
> 
> (defvar count 1)
> 
> (defun insert-bifurcating-comment ()
>   "Insert bifurcating line at cursor position"
>   (interactive)
> 
>   (let* ( (m 62) (n 69)
> 	  (lena (- m (current-column)))   ; lena = m - (current-column)
> 	  (lenb (- n (current-column))) )
> 
>     (pcase count
>       (0
>          ;; makes s to be line with repeating ";"
>          (setq-local s (make-string lena ?\;))  ; repeats lena times
> 	 (insert-bifurcation s count)
>          (setq-local count 1))
>       (1
>          ;; makes s to be line with repeating ";"
>          (setq-local s (make-string lenb ?\;))  ; string length lenb
> 	 (insert-bifurcation s count)
> 	 (setq-local count 2))
>       (2
>          ;; makes s to be line with repeating "+"
>          (setq-local s (make-string lena ?+))
> 	 (insert-bifurcation s count)
>          (setq-local count 3))
>       (_
>          ;; deactivates the bifurcating line
>          (insert-bifurcation s count)
>          (setq-local count 1)) )) )

I am done and obfuscated now. ☺


-- 
Jean

Take action in Free Software Foundation campaigns:
https://www.fsf.org/campaigns

Sign an open letter in support of Richard M. Stallman
https://stallmansupport.org/
https://rms-support-letter.github.io/

Re: Determining existence of text following point

[michael-franzese]

Currently the code inserts if the region is blank.

But I have a keybinding to change from

;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

to

;; ++++++++++++++++++++++++++++++++++++



> Sent: Wednesday, May 19, 2021 at 10:23 PM
> From: "Jean Louis" <bugs@gnu.support>
> To: michael-franzese@gmx.com
> Cc: "Eric Abrahamsen" <eric@ericabrahamsen.net>, "Skip Montanaro" <skip.montanaro@gmail.com>, "Help Gnu Emacs" <help-gnu-emacs@gnu.org>
> Subject: Re: Determining existence of text following point
>
> * michael-franzese@gmx.com <michael-franzese@gmx.com> [2021-05-19 10:29]:
> > Point will always be at the beginning of a comment on a separate line
> > 
> > The "^" shows the position of the cursor.
> > 
> >                    ^;; ;;;;;;;;;;;;;;;;;;;;;;;;;;
> > 
> >          ^;; +++++++++++++++++++++++++++
> > 
> > ^;; ----------------------------
> > 
> > I want to have a keybinding that if I continue to hit will change
> > a comment from
> > 
> > ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
> > 
> > to
> > 
> > ;; +++++++++++++++++++++++++++++++++++++
> > 
> > Currently I have the following code
> > 
> > 
> > (defun insert-bifurcation (s n)
> >    "todo"
> > 
> >    (let* ( (a (point))  (b (line-end-position))
> > 	   (line-cut (buffer-substring-no-properties a b)) )
> > 
> >       (when (or (not (string-match
> > 		        "[^[:blank:]]" line-cut)) (eolp))
> >          (pcase n
> > 
> > 	    (0
> >   	        (save-excursion (insert s))
> > 	        (comment-region a b))
> > 	    
> >     	    ((or 1 2 3 4 5)
> > 	        (delete-region a b)
> > 	        (save-excursion (insert s))
> > 		(comment-region a b))
> > 
> >             (_
> > 	        (delete-region a b))) )) )
> > 
> > (defvar count 1)
> > 
> > (defun insert-bifurcating-comment ()
> >   "Insert bifurcating line at cursor position"
> >   (interactive)
> > 
> >   (let* ( (m 62) (n 69)
> > 	  (lena (- m (current-column)))   ; lena = m - (current-column)
> > 	  (lenb (- n (current-column))) )
> > 
> >     (pcase count
> >       (0
> >          ;; makes s to be line with repeating ";"
> >          (setq-local s (make-string lena ?\;))  ; repeats lena times
> > 	 (insert-bifurcation s count)
> >          (setq-local count 1))
> >       (1
> >          ;; makes s to be line with repeating ";"
> >          (setq-local s (make-string lenb ?\;))  ; string length lenb
> > 	 (insert-bifurcation s count)
> > 	 (setq-local count 2))
> >       (2
> >          ;; makes s to be line with repeating "+"
> >          (setq-local s (make-string lena ?+))
> > 	 (insert-bifurcation s count)
> >          (setq-local count 3))
> >       (_
> >          ;; deactivates the bifurcating line
> >          (insert-bifurcation s count)
> >          (setq-local count 1)) )) )
> 
> I am done and obfuscated now. ☺
> 
> 
> -- 
> Jean
> 
> Take action in Free Software Foundation campaigns:
> https://www.fsf.org/campaigns
> 
> Sign an open letter in support of Richard M. Stallman
> https://stallmansupport.org/
> https://rms-support-letter.github.io/
> 
> 
>

Re: Determining existence of text following point

[michael-franzese]

> I am done and obfuscated now. ☺

Will simplify.  How can I detect a comment line composed of ";", "+", "-",
or "." because I want to insert the string if I find the following lines

First one is comment composed of ";", second one is comment composed of "+",
and the rest are comments composed of "-" and ".".

The comments could also start at any column.

;; ;;;;;;;;;;;;;;;;;;;;;;;;;

;; +++++++++++++++++++++++++++

;; --------------------------

;; ........................

> Sent: Wednesday, May 19, 2021 at 10:23 PM
> From: "Jean Louis" <bugs@gnu.support>
> To: michael-franzese@gmx.com
> Cc: "Eric Abrahamsen" <eric@ericabrahamsen.net>, "Skip Montanaro" <skip.montanaro@gmail.com>, "Help Gnu Emacs" <help-gnu-emacs@gnu.org>
> Subject: Re: Determining existence of text following point
>
> * michael-franzese@gmx.com <michael-franzese@gmx.com> [2021-05-19 10:29]:
> > Point will always be at the beginning of a comment on a separate line
> > 
> > The "^" shows the position of the cursor.
> > 
> >                    ^;; ;;;;;;;;;;;;;;;;;;;;;;;;;;
> > 
> >          ^;; +++++++++++++++++++++++++++
> > 
> > ^;; ----------------------------
> > 
> > I want to have a keybinding that if I continue to hit will change
> > a comment from
> > 
> > ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
> > 
> > to
> > 
> > ;; +++++++++++++++++++++++++++++++++++++
> > 
> > Currently I have the following code
> > 
> > 
> > (defun insert-bifurcation (s n)
> >    "todo"
> > 
> >    (let* ( (a (point))  (b (line-end-position))
> > 	   (line-cut (buffer-substring-no-properties a b)) )
> > 
> >       (when (or (not (string-match
> > 		        "[^[:blank:]]" line-cut)) (eolp))
> >          (pcase n
> > 
> > 	    (0
> >   	        (save-excursion (insert s))
> > 	        (comment-region a b))
> > 	    
> >     	    ((or 1 2 3 4 5)
> > 	        (delete-region a b)
> > 	        (save-excursion (insert s))
> > 		(comment-region a b))
> > 
> >             (_
> > 	        (delete-region a b))) )) )
> > 
> > (defvar count 1)
> > 
> > (defun insert-bifurcating-comment ()
> >   "Insert bifurcating line at cursor position"
> >   (interactive)
> > 
> >   (let* ( (m 62) (n 69)
> > 	  (lena (- m (current-column)))   ; lena = m - (current-column)
> > 	  (lenb (- n (current-column))) )
> > 
> >     (pcase count
> >       (0
> >          ;; makes s to be line with repeating ";"
> >          (setq-local s (make-string lena ?\;))  ; repeats lena times
> > 	 (insert-bifurcation s count)
> >          (setq-local count 1))
> >       (1
> >          ;; makes s to be line with repeating ";"
> >          (setq-local s (make-string lenb ?\;))  ; string length lenb
> > 	 (insert-bifurcation s count)
> > 	 (setq-local count 2))
> >       (2
> >          ;; makes s to be line with repeating "+"
> >          (setq-local s (make-string lena ?+))
> > 	 (insert-bifurcation s count)
> >          (setq-local count 3))
> >       (_
> >          ;; deactivates the bifurcating line
> >          (insert-bifurcation s count)
> >          (setq-local count 1)) )) )
> 
> I am done and obfuscated now. ☺
> 
> 
> -- 
> Jean
> 
> Take action in Free Software Foundation campaigns:
> https://www.fsf.org/campaigns
> 
> Sign an open letter in support of Richard M. Stallman
> https://stallmansupport.org/
> https://rms-support-letter.github.io/
> 
> 
>

Re: Determining existence of text following point

[michael-franzese]

I could use something based on the follewing

 (if (looking-at "[[:alnum:]]+")

But I am quite unsure about the regexp.  If there exists at least a character,
I would not insert any text.


> Sent: Tuesday, May 18, 2021 at 11:05 AM
> From: "Eric Abrahamsen" <eric@ericabrahamsen.net>
> To: michael-franzese@gmx.com
> Cc: "Skip Montanaro" <skip.montanaro@gmail.com>, "Help Gnu Emacs" <help-gnu-emacs@gnu.org>
> Subject: Re: Determining existence of text following point
>
> michael-franzese@gmx.com writes:
> 
> >    Would like to delete and insert a string "s" only if there is no text
> >    folloming point.
> >
> >    (delete-region (point) (line-end-position))
> >    (save-excursion (insert s))
> 
> There's a function for this: `eolp'
> 
> Return t if point is at the end of a line.
> ‘End of a line’ includes point being at the end of the buffer.
>

Re: Determining existence of text following point

[Jean Louis]

* michael-franzese@gmx.com <michael-franzese@gmx.com> [2021-05-18 01:32]:
>    Would like to delete and insert a string "s" only if there is no text
>    folloming point.
> 
>    (delete-region (point) (line-end-position))
>    (save-excursion (insert s))

(defun my-insert-on-eol (s)
  (when (eolp)
    (insert s)))


-- 
Jean

Take action in Free Software Foundation campaigns:
https://www.fsf.org/campaigns

Sign an open letter in support of Richard M. Stallman
https://stallmansupport.org/
https://rms-support-letter.github.io/