Re: Better emoji support

[Eli Zaretskii]

> From: Robert Pluim <rpluim@gmail.com>
> Cc: Juri Linkov <juri@linkov.net>,  lists@traduction-libre.org,
>   emacs-devel@gnu.org
> Date: Sun, 19 Sep 2021 20:10:22 +0200
> 
>     Eli> Hmm...  Robert, I see quite a few characters that now belong to the
>     Eli> emoji script, which shouldn't be there, AFAIU.  The above is one of
>     Eli> them (AFAIK, the Arrows block doesn't belong to Emoji).  But there 
> are
>     Eli> more stark cases, for example:
> 
> The whole block might not, but some of the codepoints do:
> 
> 2194..2199    ; Emoji                # E0.6   [6] (↔️..↙️)    left-right 
> arrow..down-left arrow

Only if followed by a variation selector VS-16, right?

>     Eli>   (aref char-script-table ?#) => emoji
>     Eli>   (aref char-script-table ?0) => emoji
> 
> I donʼt see that here (and itʼs definitely not the
> intention). Blocks.awk skips any ASCII codepoints (and those both
> evaluate to "latin" here). Could you double-check your
> lisp/international/charscript.el?

I see them there:

    (#x0023 #x0023 emoji) ; Autogenerated emoji
    (#x002A #x002A emoji) ; Autogenerated emoji
    (#x0030 #x0039 emoji) ; Autogenerated emoji
    (#x00A9 #x00A9 emoji) ; Autogenerated emoji
    (#x00AE #x00AE emoji) ; Autogenerated emoji

Which corresponds to these lines in emoji-data.txt:

  0023          ; Emoji                # E0.0   [1] (#️)       hash sign
  002A          ; Emoji                # E0.0   [1] (*️)       asterisk
  0030..0039    ; Emoji                # E0.0  [10] (0️..9️)    digit 
zero..digit nine
  00A9          ; Emoji                # E0.6   [1] (©️)       copyright
  00AE          ; Emoji                # E0.6   [1] (®️)       registered

>     Eli> It seems like these characters ended up in the emoji script because
>     Eli> they should render as emoji when followed by variation selectors?  
> But
>     Eli> in that case, the place to do this is in composition-function-table,
>     Eli> if we can, and if we cannot, let's for now decide we don't support
>     Eli> these sequences, because the cure sounds worse than the disease with
>     Eli> our current infrastructure.
> 
>     Eli> Am I missing something?
> 
> Are now saying that we only want to add to the emoji script those
> characters with Emoji_Presentation=Yes?

Yes, I think so.  Are there any downsides to that?