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RE: intertwined specs

• From: Charles Reitzel <creitzel@m...>
• To: xml-dev@l...
• Date: Mon, 19 Feb 2001 14:47:27 -0500 (EST)

A roadmap is a basic requirement to make sense out of the flurry of new
drafts.  Postings on this list, although helpful, are not sufficient.

Without having read the details of how XSLT, XQuery, XPath and XSchema will
all inter-connect, it also strikes me as basic that XML Schema Data Types be
released ASAP and that the developer community be given 6 months to put it
through it's paces before loading it down any further.

Separating data types from structures allows XPath to be layered in between:
XSchema Structures => XPath => XSchema Data Types.  It also allows alternate
schema/rule languages to be defined at any level: over XPath, Data Types or
standalone.

A use case for reading data types separately from validation is SOAP
messaging/rpc.  Schema driven deserialization is a natural and may or may
not make use of schema validation.  Another use of XML Data Types (XData?)
sans XPath or validation would be the ITU XML Encoding Rules for ASN.1
mentioned just Friday by Mr. Dubuisson.

I think Post Schema Validation Infoset is a bit of a misnomer.  I don't
think *document* validation is required to lookup the data type and/or
default value in the schema for an element or attribute.  Would Schema
Complete and/or DTD Complete be better terms?  This is similar to expansion
-or not- of external parsed entities and DTD attribute defaults for
well-formed checking.  If expansion of entities and DTD attributes are
optional, a similar option is necessary for inclusion of schema data.

Also, the obvious item missing from XML Data Types is ordering and equality
rules.   A modest proposal: just push the XSLT sort order options down to
the data type.  These are numeric=yes/no and case-sensitive=yes/no.  The
defaults are "no" and "yes", respectively, and imply case-sensitive, text
ordering.  XPath and XSLT would both benefit from ordering and equality
rules.  This proposal works well w/out a schema, in that the defaults apply
without controversy.

IMHO, without some corresponding XML database standard, XML Query doesn't
even makes sense as a standard.  Besides, isn't XSLT already a quite decent
query language?  I took a quick look at the XQuery requirements and didn't
see much that XSLT doesn't already do.  The W3C is looking a bit like a kid
eating french fries, stuffing more into it's mouth before it has chewed and
swallowed the previous mouthful.

take it easy,
Charles Reitzel

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