From: ori@eigenstate.org
Subject: Re: [REPOST] ksh: utf8 full width character support for emacs.c
To: op@omarpolo.com, schwarze@usta.de
Cc: tech@openbsd.org
Date: Sun, 06 Apr 2025 22:48:12 -0400

Quoth Ingo Schwarze <schwarze@usta.de>:
> Hello Omar,
> 
> Omar Polo wrote on Sun, Mar 30, 2025 at 08:37:06PM +0200:
> 
> > grapheme clusters (i.e. what a user percieves as a "character")
> > can be more than one code point long.
> 
> That is (more or less) accurate - and ludicrously complicated.
> There is a long annex to the Unicode standard on this topic,
>   Unicode Text Segmentation, Unicode Standard Annex #29
>   https://www.unicode.org/reports/tr29/
> 
> Note that "grapheme clusters" are not the same as "user-percieved
> characters", and there are several different types of grapheme clusters
> (legacy, extenbded, tailored, ...).
> 

For extra trivia: there are some Indian languages (Kannada, IIRC,
is an example), where a combining codepoint combines with multiple
surrounding glyphs, and not just the one codepoint before it.

Rendering text is hard.