On Thu, Oct 28, 2021 at 08:08:53AM +0200, Alexandre Garreau wrote:

[...]

> Oh ok, but do they define what a paragraph is?

This is... complicated. See [0], especially [1], and the references
from there. My take (but note that I'm an analphabet here) is that
there usually will be a surrounding level of "markup" (e.g. XML,
HTML, something else) which decides what a paragraph is. The usual
convention of an empty line separating paragraphs is fine as that
"surrounding level", too. Unicode also has a "paragraph separator",
\u2029, in case you need one.

However that separation is done, the BIDI algorithm doesn't care.
It works exclusively whithin one paragraph, whatever happens in one
paragraph doesn't touch the others, and thus it wants to be fed
single paragraphs.

Read the refs. Very instructive (and you'll learn to appreciate a
bit more what a labour of love Eli has been doing before he became
our maintainer).

Cheers

[0] https://www.unicode.org/reports/tr9/
[1] https://www.unicode.org/reports/tr9/#Basic_Display_Algorithm

 - t