[
Lists Home |
Date Index |
Thread Index
]
Tim Bray <tbray@textuality.com> wrote:
> 3. expressing syntactic restrictions on the way the vocabularies
> combine
...
> #3 is harder still, and is addressed, if not completely solved, by more
> more modern schema languages like XSD and RNG.
ISO/IEC Document Schema Definition Languages (DSDL) -- Part 4: Selection
of Validation Candidates is trying to solve this problem. I am the
project editor of Part 4. Although this activity is not well-known,
it has a long history and is expected to become a DIS next year. By
the way, Part 2 of DSDL is RELAX NG.
An interesting schema [1] for the combination of XHTML2 + MathML + SVG
+ EGIX + ContactXML + HLink + RDF + XML Character Entities document was
created by Mimasa Ishikawa of Keio W3C. This schema is written in MNS
[2] designed and implemented by James Clark. MNS is inspired by the
DSDL Part 4 committee draft [3] as well as RELAX Namespace [4]. MNS is
an important input to DSDL VC. Namespace Switchboard [5] by Rick
Jelliffe proposes some interesting changes. In the underlying
processing model (e.g., [6]), DSDL-VC is expected to be implemented as
a SAX event dispatcher, which dispatches SAX events to other validators
(which may be RELAX NG, WXS, RDF Schema, Topic Map Constraint Language,
DTDs, ...). On the basis of comment disposition [7], ISO/IEC SC34 WG1
will soon create a Final Committee Draft for DSDL. Some interesting
discussion is conducted at the DSDL-discussion mailing list (To join
this ML, see www.dsdl.org). Please keep fingers crossed.
That said, the scope of DSDL-VC is validation only. Application
programs does not have to be implemented on top of namespace-based
dispatching.
[1] Sample schema and instance
schema: http://www.w3.org/People/mimasa/test/schemas/rng/hybrid.mns
instance: http://www.w3.org/People/mimasa/test/xhtml2/hybrid.xhtml
[2] MNS
http://www.thaiopensource.com/relaxng/mns.html
[3] DSDL Part 4 CD
http://www.y12.doe.gov/sgml/sc34/document/0363.htm
[4] RELAX Namespace
http://www.y-adagio.com/public/standards/iso_tr_relax_ns/dtr_22250-2.doc
[5] Namespace Switchboard
http://www.topologi.com/resources/NamespaceSwitchboard.html
[6] Comment disposition of JTC 1/SC 34 N 363 CD Ballot for 19757-4
http://www.y12.doe.gov/sgml/sc34/document/0415.htm
[7] Prototypical implementation of "Divide and Validate"
http://www.xml.gr.jp/relax/divideAndValidate.html
--
MURATA Makoto <murata@hokkaido.email.ne.jp>
|
