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Re: Next steps for the ARIA syntax discussion

From: Elliotte Harold <elharo@metalab.unc.edu>
Date: Wed, 04 Jun 2008 06:17:42 -0700
Message-ID: <484695F6.2000808@metalab.unc.edu>
To: Mark Birbeck <mark.birbeck@webbackplane.com>
Cc: Charles McCathieNevile <chaals@opera.com>, Robert J Burns <rob@robburns.com>, Al Gilman <Alfred.S.Gilman@ieee.org>, "Henry S.Thompson" <ht@inf.ed.ac.uk>, "www-tag@w3.org List" <www-tag@w3.org>, "public-html@w3.org WG" <public-html@w3.org>, "public-xhtml2@w3.org WG" <public-xhtml2@w3.org>, "wai-xtech@w3.org WAI-XTECH" <wai-xtech@w3.org>

Mark Birbeck wrote:

> The first thing I would do is prise apart the syntax and the infoset.
> I don't see any reason why the underlying representation of a DOM
> can't be taken as given, even if we fiddle around to remove the need
> for prefix-explosion in the mark-up.
> 

Cart: let me just attach you to the front of the horse here.

Syntax is the only thing we have. Syntax is the only thing XML brings to 
the table. There is no common data model for XML, and fundamentally 
there can't be one. Syntax is interoperable across domains, operating 
systems, organizations, and countries. Data models don't usually survive 
the transition from one application to the next, much less the 
transition from one computer to another, or one organization to another.

And of all the things XML has brought to the table, about the only one I 
can think of that is worse than namespaces is DOM. It's ugly, 
inconsistent, memory-intensive, slow, thoroughly despised by users, and 
frankly just hideous.

For a spec designed for long-term storage and wire transport, any object 
model is a non-starter. It is flat-out impossible to put objects on the 
wire. Serialized objects are an oxymoron, a self-contradicting fantasy. 
  They are the perpetual motion machine of computing. There's a reason 
object serialization schemes have failed time and again, and it's not 
just because we haven't invented the right one yet. Defining XML in 
terms of any object model would not just be a bad idea. It would be 
impossible.

(This is not to the say, by the way, that there might not be better 
syntaxes than the one we've labeled XML. There are almost certainly are. 
But any such improved syntax would have to be just that: syntax, not an 
object model.)

XML did prise apart syntax and the infoset. That's was one of its most 
significant innovations, perhaps its most significant. The infoset is 
not a core feature of XML. It is simply one understanding of an actual 
XML document, not the understanding of a document. The infoset may or 
may not be useful in any given application and developers are free to 
use it or not as they see fit. The genius of XML was precisely in 
defining an interoperable syntax while allowing many different models of 
that syntax. To define a single model while allowing many different 
syntaxes is precisely the opposite of what XML is about, and why XML has 
succeeded.

-- 
Elliotte Rusty Harold  elharo@metalab.unc.edu
Java I/O 2nd Edition Just Published!
http://www.cafeaulait.org/books/javaio2/
http://www.amazon.com/exec/obidos/ISBN=0596527500/ref=nosim/cafeaulaitA/
Received on Wednesday, 4 June 2008 13:18:25 GMT

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