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Re: Vocabulary Combination

• To: xml-dev@l...
• Subject: Re: Vocabulary Combination
• From: MURATA Makoto <murata@h...>
• Date: Sat, 31 May 2003 18:28:49 +0900
• In-reply-to: <3ED67CA3.6090001@t...>
• References: <3ED67CA3.6090001@t...>

Tim Bray <tbray@t...> 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@h...>

• References:
  • Re: Vocabulary Combination
    • From: Tim Bray <tbray@t...>

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