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

On Tuesday 2013-10-29 11:14 -0700, Tab Atkins Jr. wrote:
> On Mon, Oct 28, 2013 at 6:18 PM, L. David Baron <dbaron@dbaron.org> wrote:
> > I don't think "expose" is what regions is doing here.  This isn't a
> > pre-existing primitive.  Sure, you can make it a new primitive and
> > rebuild other things on top of it -- but that doesn't make it the
> > thing they were built on before, nor does it make it the right
> > primitive to build them on (which I don't think it is).
> 
> Well, right now we've got at least two things (multicol and paged
> displays) that do "flow content between separate boxes", and a bunch
> more planned/discussed things that are similar, such as grid-cell
> chaining, footnotes, etc.

That doesn't contradict what I said, nor do I disagree with it.
(Same for your third paragraph.)

> It seems like Regions is an underlying primitive here, as it exposes
> the "flow between boxes" ability, and the "arbitrarily move a box into
> another location".  I'm not sure how to expose these types of things
> to authors otherwise.

I disagree with the "is an underlying primitive" statement.  You can
make it into one by rebuilding other things on top of it, but that
doesn't mean it currently is one.

> In general, it seems like things that use those two abilities will
> become more common over time, rather than less.  We don't want to have
> to be the gatekeepers that define every new bit of functionality
> before authors can use it - that just means CSS continues to grow, and
> do it slowly, forever.  We should be exposing this or something like
> it, so authors can invent their own abilities and we can clean up
> afterwards with simpler, more efficient sugar on top of it for common
> things.

Agreed, but I think the underlying primitives we expose to do that
should actually be more like primitives -- they shouldn't involve
things like implicit multi-pass layout (which isn't in the things
you cite that are built on top of them).

-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)