Re: [emacs-bidi] Suboptimal display-reordering in minibuffer

[Eli Zaretskii]

> Date: Mon, 28 Jun 2010 09:14:36 +0300
> From: Amit Aronovitch <address@hidden>
> Cc: Eli Zaretskii <address@hidden>, address@hidden
> 
> > >Btw, there's something I overlooked before: why exactly is ^ב
> > >considered a strong R2L character?  Could you please go to it in the "
> > >*Echo Area 0/1*" buffer, type "C-u C-x =", and show what Emacs tells
> > >about that character?
> >
> > First of all, I don't think your procedure works.  You can make the
> > message appear, and with care you can get a cursor on top of it, but
> > typing C-u (or most anything else) changes the buffer contents---it's
> > not called the Echo Area for nothing!  To get your hands on the
> > character you'd have to write a function that grabs the contents of the
> > buffer and bind it to a key, or in some other way avoid echoing.
> >
> >
> How exactly did you get the ^x?
> The echo messages that I see here look like C-x.

That's exactly what bothers me.

> maybe the handling of uninsertables is done AFTER reordering

No.  Reordering is always _after_ any "handling".  In Emacs, redisplay
is generally done only when Emacs is idle.  And bidi reordering is
part of redisplay.

> so from the POV of the reordering
> algorithm it is considered a single character as Eli said.

Yes, but which character?  What I want to know is, if it wasn't ב
followed or preceded by a caret, how come Emacs decided to render this
paragraph right-to-left?  The bidirectional properties of characters
are derived from the UnicodeData.txt file, the Unicode database of
character properties, so no character that is not in that database can
ever be considered strong R.  (In fact, any character not in that
database will cause Emacs to abort.)