Re: [relax-ng] Re: DOM Abstract Schemas revisited

[John Cowan <cowan@mercury.ccil.org>]

Kohsuke KAWAGUCHI scripsit:

> I think this is where I misunderstood you. I thought you were trying to
> map RNG as natural as possible.

No, I wanted to see whether AS (which is going into the DOM, whether
we like it or not) can be used to represent RNG schemas or not.

> The element/attribute mixed content model is still a very big problem.
> You suggest to split it into multiple content models, but sometimes it
> takes exponential time to the size of input. Consider:

I presume you mean "exponential space".
Your example is indeed a compelling one.

> Another problem is the semantics of <interleave>. Firstly, this is not
> SGML-&, so the "all" compositor cannot be used for <interleave>.
> Secondly, the "all" compositor is limited to the top-level, whereas you
> can write <interleave> anywhere. And expanding interleave can again take
> exponential time to the size of input. Even worse, this exponential
> explosion happens to every-day schemas.

I completely agree.  For AS to adapt to RNG, it would need an explicit
representation of "interleave" distinct from "all".

My point is:  It is not yet too late for the RNG TC to influence the
AS process.  If we ask for a few things such as "interleave" and
wildcarded names to be added to AS, we can get a model which can,
with some creaking and groaning, support RNG.   Not every detail
of RNG, but AS doesn't support every detail of DTDs or W3CXS either.

I am not a member of the TC, but I do *strongly urge* that this
matter be taken up ASAP, because of the coupling with the W3C DOM WG.

-- 
John Cowan           http://www.ccil.org/~cowan              cowan@ccil.org
To say that Bilbo's breath was taken away is no description at all.  There
are no words left to express his staggerment, since Men changed the language
that they learned of elves in the days when all the world was wonderful.
        --_The Hobbit_