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

[Stefan Monnier <monnier@iro.umontreal.ca>]

>> Also, while I'm here.  I re-suggest to change the default of
>> bidi-paragraph-direction to left-to-right, since I think that preserves
>> backward compatibility a lot better.
> You never explained what backward compatibility is alluded to here.

Emacs has done only ever left-to-right until now.  So if we use
right-to-left where left-to-right was needed, it's a regression, whereas
if we use  left-to-right where right-to-left was needed it's not.

> Anyway, that suggestion was not forgotten, I just want to wait with it
> a bit more, to see if any additional problems are spotted with the
> dynamic paragraph direction.

OK.

>> We can set it to nil in the major modes where we know it can be
>> useful, such as text-mode.
> What other modes will need this?

No idea.

> Also, do we care about the case that the user sets the default value
> to nil?

Not really, but I think it's good to keep the current explicit settings
to `left-to-right' in things like prog-mode.  It's also OK to add such
settings even if the default is already left-to-right.


        Stefan