Re: Use Emacs' default value of "bidi-paragraph-direction" in orgmode

[ST <smntov@gmail.com>]

On Sun, 2018-06-17 at 16:10 +0300, Eli Zaretskii wrote:
> > From: ST <smntov@gmail.com>
> > Cc: Nicolas Goaziou <mail@nicolasgoaziou.fr>, Emacs-orgmode@gnu.org
> > Date: Sun, 17 Jun 2018 15:29:58 +0300
> > 
> > 1. Do you agree that the vast majority of all the documents in human
> > history were/are EITHER ltr OR rtl? Meaning that mixed ltr/rtl texts are
> > minority that we should not take care of...
> > 2. Do you agree that for pure ltr texts org headings should appear to
> > the left and for pure rtl texts org headings should appear to the right?
> > 
> > If you agree with both (1) and (2) - we should put nil as default value,
> > as this will enable (2).
> 
> I agree with (1) and (2), but your conclusion doesn't follow from
> that.  The value nil means that the base directionality of
> _each_paragraph_ is determined dynamically.  It does NOT mean that the
> whole buffer will have the same directionality for all of its
> paragraphs.  With nil, some paragraphs could have RTL direction, and
> others LTR.  Worse, headings could have one direction and their bodies
> another.  A single character at the beginning of a paragraph might
> change that paragraph's base direction.  You don't want that with your
> users.

All troubles that you describe here are relevant only for mixed ltr/rtl
texts ("a single character" is an ltr character inside an rtl text,
isn't it?), but we have agreed to exclude those as per (1). Can you give
an example of pure rtl text with the issues mentioned above?

> 
> > I'm so eager to change the defaults because we start a project where we
> > have many non_technically_savvy Windows-people who need to edit rtl org
> > files in Emacs (which is a challenge on its own). So we want the
> > experience to be as smooth as possible, but right now rtl users are
> > disadvantaged for no reason (as with nil - BOTH ltr AND rtl views can be
> > achieved).
> 
> Users of RTL languages should have bidi-paragraph-direction in Org
> buffers set to right-to-left, not to nil.  The value of nil will
> sometimes cause the heading to appear at the left while the body
> appears on the right, or vice versa, which is the worst of all worlds.

Again, only for mixed ltr/rtl texts, until you prove (by example)
otherwise.

> I see no reason why non-technically-savvy people couldn't learn that
> they need to set a variable when they start editing text of a known
> directionality.

If you don't have a counter-example, nil is better since that way you
have one default setting for ALL buffers and you can work with BOTH ltr
and rtl texts with the same config without the need to change anything.
Contrary to mixed ltr/rtl texts - working with pure ltr texts is common
also for rtl people.

>   That's what MS-Word users do all the time, right?

Yes, but they are used to buttons_check-boxes stuff, not lisp config
files.

Thanks!