Re: per-paragraph auto-direction, a.k.a. dir=uba

On Mon, Sep 27, 2010 at 8:31 PM, Aharon (Vladimir) Lanin
<aharon@google.com>wrote:

> Well, there are two separate issues here. One is that the UBA mangles AN
> phone numbers pretty badly. This has no direct impact on the HTML/CSS
> proposal. I have no problem sending that in, but would prefer to delay until
> after the HTML5 bug submissions are done.
>
> The other is to get bidi@unicode.org feedback on the modified first-strong
> estimation algorithm I am proposing, in the context of the dir=auto feature
> (not as a proposal to modify the UBA).
>
> However, given that fantasai and Mati and Amit have already expressed
> reservations about my proposal, and that no one has seconded it, I now
> wonder whether it's  worth troubling them over it.
>
> Aharon
>
>
Supposing you remove the special-casing of the weak-types, then there is
still the question of what to do when no strong characters are found -
return the inherited direction, or return LTR.

The UBA algorithm is only called when there is no "higher level protocol",
so it must return something in this "inconclusive" case. The default was
chosen to be LTR.
However, in our case, we have the option to return the containing element's
directionality (at least, I would not consider this option more complicated
than the UBA). This would be less disruptive if the element is empty, but
has child elements.
On the other hand, note that if you return LTR for this case as the UBA
does, at least the examples you described (EN dates and negative numbers)
would work fine.

 Amit A.

Received on Monday, 27 September 2010 20:16:10 UTC