Re: [emacs-bidi] RTL support

[Eli Zaretskii]

> Date: Thu, 24 Nov 2005 12:37:42 +0900
> From: Martin Duerst <address@hidden>
> Cc: address@hidden
> 
> Regarding LSD (least significant digit) first, that's of course
> the crucial point. If you say that making Western software
> work for RTL languages cheaply was the motivation for the
> bidi algorithm, and for making RTL languages inherently bidi,
> then you seem to say that implementing LSD first is even more
> difficult/expensive than implementing bidi.

Unless I'm missing something, these issues have nothing to do with
what we were discussing.  We weren't discussing how to encode bidi
text in a file or in general; we were discussing how to hold it within
Emacs buffers and strings.  The latter is an internal Emacs matter
that shouldn't bother users at all.  The only valid arguments for how
to store RTL text within Emacs buffers and strings are those which
compare the difficulty of adding bidi support to relevant Emacs
features.  That is, one must speak about Emacs design and structure,
not about anything else.

When we discussed this in the past, the conclusion was that storing
RTL text in the visual order will require bidi-related changes in many
places in Emacs, both in many primitive operations and in application
C and Lisp code.  By contrast, logical-order storage required changes
in a small number of well-isolated parts of low-level code, mainly in
display code and in some of the primitives that translate screen to
buffer position and back.