Eli Zaretskii wrote:


>  But Emacs does not
> have a rigid line length, so flushing the R2L lines against the right
> margin of the window makes their position depend on the window width.
> Is that okay?  (I think it is.)


FWIW: Yudit (the bidi text editor) uses right edge of window for R2L as 
you suggest (and left edge for L2R), reflowing as you resize the window. 
It apparently only line wraps though, no truncation, so no horizontal 
scrolling.