xml-dev - RE: Why the Infoset?

[Jonathan Borden <jborden@mediaone.net>]

Tim, Simon,

The question was "Why the Infoset?". You are quibling with my use of the
term serialization vs. syntax. The Infoset is neither a serialization nor a
syntax but a logical model. In general it is really hard to do anything
useful if you don't have a logical model of what you intend to do. I submit
that the only reason XML got off the ground so easily without first defining
the Infoset is that most of this work had already been done for SGML.

Substitute:

XML is a syntax for describing the logical document structure defined by the
XML Infoset,

or alternatively

XML Infoset is the logical document structure defined by the XML syntax

and my statement looses no meaning.

Jonathan Borden
http://www.openhealth.org

> -----Original Message-----
> From: Tim Bray [mailto:tbray@textuality.com]
> Sent: Tuesday, July 25, 2000 8:23 PM
> To: Simon St.Laurent; XMLDev list
> Subject: Re: Why the Infoset?
>
>
> At 07:28 PM 25/07/00 -0400, Simon St.Laurent wrote:
> >At 05:46 PM 7/25/00 -0400, Jonathan Borden wrote:
> >>XML is a serialization of a logical document structure defined
> by the XML
> >>Infoset.
> >
> >WARNING: 'XML is a serialization' is only one way to look at it.
> >
> >XML is a syntax, and the 'logical document structure' is a particular
> >interpretation of that syntax is another.
>
> What Simon said.  XML took a lot of static in its early days because it
> was "just syntax" - there are certainly a lot of people who want to think
> only in terms of object models (groves, DOMs, whatever) and see the syntax
> as disposable fluff.  Me, I think syntax is crucial.  Because describing
> data structures in a straightforward, interoperable way is really hard to
> get right and very often fails.  At the end of the day, if you
> really want
> to interoperate, you have to describe the bits on the wire.  That's what
> XML does.
>
> Think of it another way... a promise like "my implementation of SQL
> (or posix, or DOM, or XLib) will interoperate with yours" is really
> hard to keep.  A promise like "I'll ship you well-formed XML docs
> containing only the following tags and attributes" is remarkably,
> dramatically, repeatably more plausible in the real world.
>
> Not that SAX and the DOM and so on aren't good things.  But at the
> end of the day, de facto and de jure, XML is syntax. -Tim
>