Re: [CSS21] response to issue 198b

> [Original Message]
> From: Ian Hickson <ian@hixie.ch>
>
> On Fri, 13 Feb 2004, fantasai wrote:
> >>
> >>     # In this process, non-textual entities such as images are treated
> >>     # as neutral characters
> >>
> >>     as object replacement characters (U+FFFC)
> >>
> >> CSS WG response:
> >>     We don't see why this is useful.
> >
> > It gives a more precise link to the desired behavior in bidi reordering.
>
> How is it more precise? To me it seems more indirect.

Presumably fantasai considers it more precise because of what the
Unicode standard has to say on this subject in Section 3.2 of UAX#9:

"For the purpose of the bidirectional algorithm, inline objects
 (such as graphics) are treated as if they are an OBJECT
 REPLACEMENT CHARACTER (U+FFFC)."

The net effect is the same as the existing text, since this
character is of bidirectional character type ON (Other Neutral)
which is a subset of the bidirectional character category
"Neutral".   However, in the event that Unicode should tweak
the bidirectional algorithm, (perhaps making the bidirectional
algorithm into a quad-directional algorithm) were to move some
current neutrals into another category, implementers who seek
to make use of that tweak would hopefully do so in a consistent
manner without requiring a CSS 2.1.1 to make clear what the
expected behavior should be.

Not that I expect such a tweak, anytime in the foreseeable future.
The proposed change represented by this issue provides
a degree of exactitude not needed to determine the behavior
of non-textual entities with respect to the current version of the
Unicode bidirectional algorithm.  Thus I see this issue as a
useful, but not a necessary issue to be handled as fantasai
suggested.

Received on Tuesday, 17 February 2004 12:57:10 UTC