From: Eli Zaretskii <eliz@gnu.org>
To: Ihor Radchenko <yantar92@gmail.com>
Cc: 57693@debbugs.gnu.org
Subject: bug#57693: 29.0.50; Is there a more reliable version of `char-displayable-p'?
Date: Sun, 11 Sep 2022 12:43:52 +0300 [thread overview]
Message-ID: <838rmq9rfr.fsf@gnu.org> (raw)
In-Reply-To: <87v8puw945.fsf@localhost> (message from Ihor Radchenko on Sun, 11 Sep 2022 17:31:06 +0800)
> From: Ihor Radchenko <yantar92@gmail.com>
> Cc: 57693@debbugs.gnu.org
> Date: Sun, 11 Sep 2022 17:31:06 +0800
>
> Eli Zaretskii <eliz@gnu.org> writes:
>
> >> Yup. And I am asking if there is such test exposed to Elisp. Display
> >> code certainly knows when some character cannot be displayed and must be
> >> replaced by its hex code.
> >
> > The display engine only knows it retroactively, when it tried and
> > failed to display a character.
>
> The situation is similar to `string-pixel-width'.
??? You rejected such methods in an earlier message, because it
required a temporary buffer, which you said will not reproduce the
exact environment of the buffer where you want to show the character.
Or what am I missing?
> > insert the character
> > call the new magic
> > if the new magic says NO-CAN-DO
> > replace the character with something else
> >
> > If the above is acceptable, I think it can be done, although it would
> > not be very useful in other situations. But if you want to know the
> > answer before you insert the character, I don't think we know how to
> > satisfy your requirements with 100% accuracy. At least I cannot see
> > how it could be done; maybe someone else will.
>
> The described approach should be acceptable.
> What I have in mind is a function like
>
> (insert-displayable '("fancy version" "backup"))
>
> The function will try to insert "fancy version" first; check if all the
> characters are displayable, and replace the inserted text with "backup"
> if not.
OK, I will see what I can do.
next prev parent reply other threads:[~2022-09-11 9:43 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-09 13:25 bug#57693: 29.0.50; Is there a more reliable version of `char-displayable-p'? Ihor Radchenko
2022-09-09 13:38 ` Eli Zaretskii
2022-09-09 22:25 ` Stefan Kangas
2022-09-10 6:01 ` Eli Zaretskii
2022-09-10 6:06 ` Ihor Radchenko
2022-09-10 6:35 ` Eli Zaretskii
2022-09-10 6:44 ` Ihor Radchenko
2022-09-10 4:48 ` Ihor Radchenko
2022-09-10 6:24 ` Eli Zaretskii
2022-09-10 6:37 ` Ihor Radchenko
2022-09-10 7:56 ` Eli Zaretskii
2022-09-10 8:17 ` Ihor Radchenko
2022-09-10 8:42 ` Eli Zaretskii
2022-09-11 9:31 ` Ihor Radchenko
2022-09-11 9:43 ` Eli Zaretskii [this message]
2022-09-11 10:07 ` Eli Zaretskii
2022-09-12 5:46 ` Ihor Radchenko
2022-09-12 11:15 ` Eli Zaretskii
2022-09-13 1:44 ` Ihor Radchenko
2022-09-13 11:19 ` Eli Zaretskii
2022-09-14 1:52 ` Ihor Radchenko
2022-09-14 2:43 ` Eli Zaretskii
2023-02-17 19:18 ` Stefan Kangas
2023-02-17 19:29 ` Eli Zaretskii
2023-02-17 22:31 ` Stefan Kangas
2023-02-18 6:56 ` Eli Zaretskii
2023-02-18 9:00 ` Stefan Kangas
2023-02-18 9:18 ` Eli Zaretskii
2023-02-18 11:32 ` Ihor Radchenko
2023-02-18 11:56 ` Eli Zaretskii
2023-02-19 11:31 ` Ihor Radchenko
2023-02-19 11:55 ` Eli Zaretskii
2023-02-19 12:08 ` Ihor Radchenko
2023-02-19 12:23 ` Eli Zaretskii
2023-02-19 14:19 ` Ihor Radchenko
2023-02-19 15:02 ` Eli Zaretskii
2023-02-18 11:35 ` Ihor Radchenko
2023-02-18 12:00 ` Eli Zaretskii
2022-09-12 5:24 ` Ihor Radchenko
2022-09-09 13:46 ` Robert Pluim
2022-09-09 22:25 ` Stefan Kangas
2022-09-10 4:56 ` Ihor Radchenko
2022-09-10 6:02 ` Eli Zaretskii
2022-09-10 4:53 ` Ihor Radchenko
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