[emacs-bidi] Re: Callbacks?

[Benjamin Riefenstahl]

Hi Eli, Martin,


> Martin Duerst wrote:
>> In this specific case, there are two other possible positions for
>> the [LRM] (logical):
>>     <x y='ABC[LRM]'>DEF ghi</x>   and
>>     <x y='ABC'>[LRM]DEF ghi</x>
>> But now, we have made the [LRM] part of the attribute value or the
>> element content. In both cases, we have changed the content of our
>> *data* just to solve some display problems of the *markup*. It
>> should be clear that this is completely out of question

Eli Zaretskii wrote:
> I'm not sure why.  LRM and its ilk are just characters, albeit
> normally invisible ones.  Why is it ``absolutely out of the
> question'' to have them as part of the strings in XML?

You can have them as part of the values in XML.  But we also want to
be able to store data that doesn't have them in the same XML format.
We don't want to change the data just so that the XML looks right in
an editor.  Display of the XML in a text editor is usually not the
primary purpose of using XML.  Even though it is usefull, for
debugging applications that use XML, that XML is just text.

>> In any case, we are still left with two problems: Generic XML does
>> not have these directives
>
> Then generic XML is inappropriate for bidi text,

If I understand the issue right, it may currently be inappropriate to
display XML with bidi in a generic text editor that strictly applies
the Unicode rules.

Of course Emacs is not just any old editor.  I think the issue can be
solved at the Lisp level by introducing hidden directionality
overrides when reading XML and stripping them out when writing,
similarly to what longlines-mode does now with linebreaks.  This is
not a problem that has to be fixed at the C level, I think.


benny