Re: bidi-display-reordering is now non-nil by default

[Eli Zaretskii <eliz@gnu.org>]

> From: David Kastrup <dak@gnu.org>
> Date: Sun, 31 Jul 2011 12:35:40 +0200
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > Maybe.  Bidi is a feature of display, i.e. it's impossible to
> > correctly display text in some scripts without it.  With today's deep
> > and wide m17n, whereby file names and network addresses can use R2L
> > characters, saying "my mode doesn't have bidi" is tantamount to saying
> > "my mode doesn't support certain cultures".
> 
> Emacs is a desktop environment with at best marginal
> internationalization, and editing texts is only a small part of its
> functionality.  I think it is delusional to prescribe that all modes and
> programming languages should in the name of culture-friendliness be
> thought of as bidirectional by default when virtually no aspect of
> Emacs' user interfaces (short of tutorials in multiple languages)
> departs from English.

I wasn't talking about the UI, I was talking mainly about the text we
display in the window.  For example, Dired mode can say "I have no
bidi", but then it will display file names that use R2L characters in
a way that makes them barely readable.  Rmail can say "I have no
bidi", but then email messages written in R2L scripts will be
unreadable.  Etc., etc.  This happens because R2L scripts from outside
Emacs seep into Emacs, whether we want that or not.

Btw, some small portion of this leaks into the UI as well.  For
example, the name of a buffer that visits a file whose name includes
R2L characters will be displayed in the mode line and in the
appropriate menu items.  (The former is supported by the current code
base, the latter depends on the toolkit, but should generally work as
well.)  So, while it's true that the Emacs is only marginally
internationalized, the environment in which we work every day already
requires that even the UI should support bidi.  Otherwise, users who
_really_ need bidi will not be satisfied, and will turn to other
applications for their needs.  The net effect will be that the
addition of bidi to Emacs will become a futile exercise.