Re: Reading text properties from a yanked text

["Nicolas P. Rougier (inria)" <nicolas.rougier@inria.fr>]

Eli Zaretskii [2022-11-27 at 08:14] wrote:
> Because "Hello" is just a string, with no properties.  The 
> "Hello" that you
> propertized and inserted is long gone by the time you evaluate 
> case 2.  The
> mere fact that both strings have the same text "Hello" doesn't 
> mean they are
> the same string object.  And text properties in Emacs are 
> properties of
> specific objects.
> 
> Try this instead:
> 
>   (let ((str (propertize "Hello" 'face 'bold)))
>     (insert str)
>     (text-properties-at 0 str))
> 
> This makes sure the same string that gets inserted is passed to
> text-properties-at, and produces the results you expect.

Thanks for the explanation. I think I get it (but it is still is a 
bit confusing to me).

For example this returns (face bold):

(with-temp-buffer
  (insert (propertize "Hello" 'face 'bold))
  (kill-region (point-min) (point-max))
  (yank)
  (text-properties-at 0
        (buffer-substring (point-min) (point-max))))

While this returns nil:

(with-temp-buffer
  (insert (propertize "Hello" 'face 'bold))
  (kill-region (point-min) (point-max))
  (insert (format "(text-properties-at 0 \"%s\")"
                  (current-kill 0)))
  (eval-buffer))


Nicolas

-- 
Nicolas P. Rougier —— www.labri.fr/perso/nrougier
Institute of Neurodegenerative Diseases, Bordeaux