Re: Exposing Fundamental Primitives (was: [css-regions] Named Flows, Elements and Box Generation)

On Monday 2013-10-28 17:02 -0700, Tab Atkins Jr. wrote:
> On Mon, Oct 28, 2013 at 4:56 PM, L. David Baron <dbaron@dbaron.org> wrote:
> > On Monday 2013-10-28 19:46 -0400, Brian Kardell wrote:
> >> Apologies for delayed response to this thread, feel like i helped instigate
> >> some of this discussion via other channels and then didn't show up to
> >> participate when it came up.
> >>
> >> Numerous WG members are of the opinion that we need to, as the Extensible
> >> Web Manifesto says, prioritize explaining the magic and exposing the
> >> fundamental primitives in the system.  I won't rehash the rationale for
> >> this, but encourage you to read it for yourself and the plenty of articles
> >> written about it.  I will note though that it explicitly states explains
> >> how this helps us develop better high level apis - that we definitely want
> >> them.
> >
> > Regions don't seem anywhere close to a fundamental primitive --
> > frankly, they're higher-level and more complex than most of the
> > other formatting concepts exposed by CSS.  Things like
> > http://dev.w3.org/csswg/css-regions/#regions-visual-formatting-details
> > involve substantial complexity (implicitly running algorithms in
> > other parts of CSS in multiple passes, because of the way flowing
> > into regions can violate the ordering assumptions of other layout
> > systems).
> 
> One can disagree about what level you have to go to in order to reach
> "fundamental", but that's not relevant here.
> 
> Regions, or at least something very similar to them, are clearly the
> primitive underlying Multicol and some of the more exotic Page
> features.

I don't think so -- these other features all describe their layout
model in a way allows implementations to do layout in a specific
order without such a multi-pass model.  And I'm not convinced that
the complex multi-pass model is regions actually allows describing
things like the intrinsic sizing of multicol.

-David

-- 
𝄞   L. David Baron                         http://dbaron.org/   𝄂
𝄢   Mozilla                          https://www.mozilla.org/   𝄂
             Before I built a wall I'd ask to know
             What I was walling in or walling out,
             And to whom I was like to give offense.
               - Robert Frost, Mending Wall (1914)