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

[Chong Yidong <cyd@stupidchicken.com>]

Eli Zaretskii <eliz@gnu.org> writes:

> What's wrong with using the `display' property with a special value,
> as I suggested a few mails ago?  It _is_ a character property, isn't
> it?

I'll have to think more about it, but I am not sure it's a good idea.
The display property is already used for a lot of other unrelated
purposes, like variable-width spaces.  So if you want to mark out a bidi
segment on a stretch of text that already has other display properties
present, you'd currently have to do some nasty merging of display specs.
Searching for the bidi display spec would be similarly annoying.  It
would be much nicer to have a separate text property specifically for
the purpose of marking out a bidi segment.

>> I don't recall the last time I ran into a problem with deferred
>> font-lock.  I seriously doubt this is a real issue.
>
> ??? Set jit-lock-defer-time to something like 2, then visit xdisp.c,
> scroll, and watch the fun.

Then don't do that.

Obviously, there is a trade-off: exploiting font-lock means more
"magically correct" segmenting; using a hack (like marking chars
special) means less dependence on the font-lock machinery.  I don't
think the latter is worth it.