Bidi paragraph direction in terminal emulators

[Eli Zaretskii via Unicode]

> From: Egmont Koblinger <egmont at gmail.com>
> Date: Sat, 9 Feb 2019 20:36:50 +0100
> Cc: Richard Wordingham <richard.wordingham at ntlworld.com>, 
> 	unicode Unicode Discussion <unicode at unicode.org>
> 
> On Sat, Feb 9, 2019 at 8:13 PM Eli Zaretskii <eliz at gnu.org> wrote:
> 
> > That's the application's problem, not the terminal's.  An application
> > that wants its column to line up _and_ wants to support complex text
> > scripts will need to move cursor to certain coordinates, not to assume
> > that 7 codepoints always take 7 columns on display.
> 
> In order to do that, an application needs to know how wide a text will
> appear, which depends on the font. How will it know it?

I don't know.  Maybe it keeps a database of character combinations
that need shaping, each one with the maximum width on display the
result can occupy.  Or maybe it does something else.  If it cannot,
and the terminal cannot either, then what you say is that some scripts
can never be supported by text terminals.