unofficial mirror of emacs-devel@gnu.org 
 help / color / mirror / code / Atom feed
From: Eli Zaretskii <eliz@gnu.org>
To: "Nicolas P. Rougier (inria)" <nicolas.rougier@inria.fr>
Cc: emacs-devel@gnu.org
Subject: Re: Reading text properties from a yanked text
Date: Sun, 27 Nov 2022 08:14:19 +0200	[thread overview]
Message-ID: <83lenwrkjo.fsf@gnu.org> (raw)
In-Reply-To: <m1zgcdxuap.fsf@inria.fr> (nicolas.rougier@inria.fr)

> From: "Nicolas P. Rougier (inria)" <nicolas.rougier@inria.fr>
> Date: Sat, 26 Nov 2022 22:35:13 +0100
> 
> I'm trying to read the properties of a yanked string and I do not 
> understand why I get a nil result:
> 
> 1. I evaluate the line below to get a bold "Hello" and I copy the 
> result in the kill ring.
> 
> (insert (propertize "Hello" 'face 'bold))
> 
> 2. If I try to get the properties of the yanked text, I get 
> nil. However, the text is displayed bold and a (text-properties-at 
> (point)) returns '(face bold) when point is on the H letter.
> 
> (text-properties-at 0 "Hello") 
> 
> 3. This version works as expected (but this is not what I need):
> (text-properties-at 0 (propertize "Hello" 'face 'bold))
> 
> Why do I get a nil result in case 2 (using Emacs 28.2) even though 
> the text is displayed bold?

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.



  parent reply	other threads:[~2022-11-27  6:14 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-26 21:35 Reading text properties from a yanked text Nicolas P. Rougier (inria)
2022-11-26 23:03 ` [External] : " Drew Adams
2022-11-27  6:07   ` Nicolas P. Rougier (inria)
2022-11-27  7:08     ` Stefan Monnier
2022-11-26 23:26 ` Gregory Heytings
2022-11-27  6:08   ` Nicolas P. Rougier (inria)
2022-11-27  6:14 ` Eli Zaretskii [this message]
2022-11-27  6:16   ` Nicolas P. Rougier (inria)
2022-11-27  7:10     ` Eli Zaretskii
2022-11-27  7:29       ` Nicolas P. Rougier (inria)
2022-12-01 23:25         ` Richard Stallman
2022-11-27  7:10     ` Gregory Heytings
2022-11-27  7:14       ` Gregory Heytings

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: https://www.gnu.org/software/emacs/

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=83lenwrkjo.fsf@gnu.org \
    --to=eliz@gnu.org \
    --cc=emacs-devel@gnu.org \
    --cc=nicolas.rougier@inria.fr \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
Code repositories for project(s) associated with this public inbox

	https://git.savannah.gnu.org/cgit/emacs.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).