How to remove the "read-only" property...

How to remove the "read-only" property...

[Davin Pearson]

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I have written some code that makes the first line read-only:

(save-excursion
  (goto-char (point-min))
  (set-text-properties (point-at-bol) (point-at-eol) '(read-only t))
  )

When I try to remove all text-properties:

(condition-case err
    (save-excursion
      (set-text-properties (point-min) (point-max) nil))
  (error
   (message "dmp-error:err=%s" err)))

It barfs with the following error message:

dmp-error:err=(text-read-only)

How do I go about removing the read-only property of the text?

TIA,

Davin

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Re: How to remove the "read-only" property...

[Emanuel Berg]

Davin Pearson wrote:

> (set-text-properties (point-at-bol) (point-at-eol) '(read-only t))

FYI

  This function is obsolete since 29.1; use
  ‘line-beginning-position’ instead.

  This function is obsolete since 29.1; use
  ‘line-end-position’ instead.

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

Re: How to remove the "read-only" property...

[Davin Pearson]

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(insert (prin1-to-string emacs-version)) => "28.1"
(insert (prin1-to-string system-type))     => gnu/linux

Should I upgrade to Emacs 29.1 ?


On Sun, 28 Aug 2022 at 19:40, Emanuel Berg <incal@dataswamp.org> wrote:

> Davin Pearson wrote:
>
> > (set-text-properties (point-at-bol) (point-at-eol) '(read-only t))
>
> FYI
>
>   This function is obsolete since 29.1; use
>   ‘line-beginning-position’ instead.
>
>   This function is obsolete since 29.1; use
>   ‘line-end-position’ instead.
>
> --
> underground experts united
> https://dataswamp.org/~incal
>
>
>

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Re: How to remove the "read-only" property...

[Davin Pearson]

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Why has point-at-bol changed to line-beginning-position?
Why has point-at-eol changed to line-end-position?

To my eyes, the defaults (point-at-bol) and (point-at-eol)
are superior to line-beginning-position and line-end-position.

I could just set an alias to get the old behaviour on my machine,
but I can't see the point of the new labels.

On Sun, 28 Aug 2022 at 19:40, Emanuel Berg <incal@dataswamp.org> wrote:

> Davin Pearson wrote:
>
> > (set-text-properties (point-at-bol) (point-at-eol) '(read-only t))
>
> FYI
>
>   This function is obsolete since 29.1; use
>   ‘line-beginning-position’ instead.
>
>   This function is obsolete since 29.1; use
>   ‘line-end-position’ instead.
>
> --
> underground experts united
> https://dataswamp.org/~incal
>
>
>

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Re: How to remove the "read-only" property...

[Eli Zaretskii]

> From: Davin Pearson <davin.pearson@gmail.com>
> Date: Sun, 28 Aug 2022 19:55:03 +1200
> 
> Why has point-at-bol changed to line-beginning-position?
> Why has point-at-eol changed to line-end-position?

They haven't.  They are aliases.

Re: How to remove the "read-only" property...

[Basil L. Contovounesios]

Davin Pearson [2022-08-28 19:55 +1200] wrote:

> To my eyes, the defaults (point-at-bol) and (point-at-eol) 
> are superior to line-beginning-position and line-end-position.

The context for why the point-at-bol and point-at-eol aliases are
deprecated is in this recent thread:
https://lists.gnu.org/r/emacs-devel/2022-08/msg00702.html

-- 
Basil

Re: How to remove the "read-only" property...

[Davin Pearson]

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A quick look at ftp://www.gnu.org reveals that the latest
version is Version 28.1 not 29.1 as you claim.

I presume you made a typo.

I much prefer the old aliases point-at-bol and point-at-eol.

Any change to this arrangement would in my opinion be
a step backwards..

*Davin.*

On Sun, 28 Aug 2022 at 19:40, Emanuel Berg <incal@dataswamp.org> wrote:

> Davin Pearson wrote:
>
> > (set-text-properties (point-at-bol) (point-at-eol) '(read-only t))
>
> FYI
>
>   This function is obsolete since 29.1; use
>   ‘line-beginning-position’ instead.
>
>   This function is obsolete since 29.1; use
>   ‘line-end-position’ instead.
>
> --
> underground experts united
> https://dataswamp.org/~incal
>
>
>

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Re: How to remove the "read-only" property...

[Stefan Monnier]

>>   This function is obsolete since 29.1; use
>>   ‘line-beginning-position’ instead.
>>
>>   This function is obsolete since 29.1; use
>>   ‘line-end-position’ instead.

Maybe the obsoletion message should also mention `pos-bol` and `pos-eol`.


        Stefan

Re: How to remove the "read-only" property...

[Stefan Kangas]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

> Maybe the obsoletion message should also mention `pos-bol` and `pos-eol`.

Agreed, now done.

Re: How to remove the "read-only" property...

[Visuwesh]

[ஞாயிறு ஆகஸ்ட் 28, 2022] Davin Pearson wrote:

>
> I have written some code that makes the first line read-only:
>
> (save-excursion
>   (goto-char (point-min))
>   (set-text-properties (point-at-bol) (point-at-eol) '(read-only t))
>   )
>
> When I try to remove all text-properties:
>
> (condition-case err
>     (save-excursion
>       (set-text-properties (point-min) (point-max) nil))
>   (error
>    (message "dmp-error:err=%s" err)))
>
> It barfs with the following error message:
>
> dmp-error:err=(text-read-only)
>
> How do I go about removing the read-only property of the text?

‘read-only’
     If a character has the property ‘read-only’, then modifying that
     character is not allowed.  Any command that would do so gets an
     error, ‘text-read-only’.  If the property value is a string, that
     string is used as the error message.

     Insertion next to a read-only character is an error if inserting
     ordinary text there would inherit the ‘read-only’ property due to
     stickiness.  Thus, you can control permission to insert next to
     read-only text by controlling the stickiness.  *Note Sticky
     Properties::.

     Since changing properties counts as modifying the buffer, it is not
     possible to remove a ‘read-only’ property unless you know the
     special trick: bind ‘inhibit-read-only’ to a non-‘nil’ value and
     then remove the property.  *Note Read Only Buffers::.

From (info "(elisp) Special Properties")

Re: How to remove the "read-only" property...

[Eli Zaretskii]

> From: Davin Pearson <davin.pearson@gmail.com>
> Date: Sun, 28 Aug 2022 19:27:07 +1200
> 
> When I try to remove all text-properties:
> 
> (condition-case err
>     (save-excursion
>       (set-text-properties (point-min) (point-max) nil))
>   (error
>    (message "dmp-error:err=%s" err)))
> 
> It barfs with the following error message:
> 
> dmp-error:err=(text-read-only)
> 
> How do I go about removing the read-only property of the text?

Bind inhibit-read-only to a non-nil value.

Re: How to remove the "read-only" property...

[Stefan Monnier]

> (condition-case err
>     (save-excursion
>       (set-text-properties (point-min) (point-max) nil))

Side note: `save-excursion` is of no use here.


        Stefan

Re: How to remove the "read-only" property...

[Stefan Monnier]

> How do I go about removing the read-only property of the text?

IME, in 99% of the cases, changes to text-properties need to be wrapped
within a `with-silent-modifications`.


        Stefan