[css3-conditional] restructured forward-compatibility aspects of @supports grammar

After reviewing the two stages of edits to
http://dev.w3.org/csswg/css3-conditional/#at-supports for
forward-compatibility to match working group resolutions over the
past few months, I've made a few edits to this section.

In particular, we agreed (at different times):
 (1) to add functions as a forwards-compatibility hook, currently
     always false
 (2) to do the same for anything in parentheses

The previous draft had these changes made in somewhat different
ways, and did the second one by doing two levels of grammar (a
general grammar and a current-level grammar).

I restructured this to no longer have two levels of grammar, but
simply have a new general_enclosed production for
forwards-compatibility:
http://dvcs.w3.org/hg/csswg/rev/4f68a956be34
http://dvcs.w3.org/hg/csswg/rev/0eeeaff20f24

(I believe publication was waiting on me to review these edits; I've
now done so, but others should now review the edits I've made.)

-David

-- 
𝄞   L. David Baron                         http://dbaron.org/   𝄂
𝄢   Mozilla                           http://www.mozilla.org/   𝄂

Received on Tuesday, 13 November 2012 23:26:15 UTC