Bidi paragraph direction in terminal emulators

Eli Zaretskii via Unicode unicode at
Sat Feb 9 14:01:21 CST 2019

> From: Egmont Koblinger <egmont at>
> Date: Sat, 9 Feb 2019 20:36:50 +0100
> Cc: Richard Wordingham <richard.wordingham at>, 
> 	unicode Unicode Discussion <unicode at>
> On Sat, Feb 9, 2019 at 8:13 PM Eli Zaretskii <eliz at> 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.

More information about the Unicode mailing list