Re: bidi-display-reordering is now non-nil by default

[Chong Yidong]

Eli Zaretskii <address@hidden> writes:

>> since there is no near-term solution, how bout turning off bidi
>> display reordering for prog-mode buffers?
>
> What for?  No one complained about it yet

I think I mentioned in an earlier message that the presence of RTL
characters mucks up the display of Emacs Lisp buffers.  This happend to
me while writing code containing RTL strings to test
string-mark-left-to-right.

> leaving it on helps find bugs and inefficiencies in the bidi display
> engine.

I understand your point, but it's not realistic to expect anyone to
"find bugs and inefficiencies" in source code buffers right now.  Those
buffers aren't displayed in an intelligible manner, because they require
missing "higher-level protocols" to display properly.

It makes a lot of sense for Emacs 24.1 to provide just the "bare" UAX9
algorithm, enabled by default in text modes (where bare UAX9 will likely
DTRT) and special modes (where Emacs can segment by hand if necessary);
with the higher-level segmentation functionality postphoned to the next
release.  In prog modes, which require that higher-level segmentation
functionality, it then makes sense to disable bidi display for now.

This would also give a lot more time to study different ways of
implementing segmentation (e.g. definining segmentation characters vs
extending the bidi code to recognize text properties).