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Re: NameValue and NameValueList data types

From: Jacek Kopecky <jacek@systinet.com>
Date: Wed, 2 Jan 2002 19:44:27 +0100 (CET)
To: Noah Mendelsohn <noah_mendelsohn@us.ibm.com>
cc: "peter.hendry" <peter.hendry@capeclear.com>, xml-dist-app <xml-dist-app@w3.org>
Message-ID: <Pine.LNX.4.33.0112220149210.6372-100000@mail.idoox.com>
 Noah,
 at first it was not clear to me that you're reacting to my post,
so maybe in some future post you might indicate that in a way.
Thanks in advance. 8-)
 Back to business: I may be underestimating the value of
datatypes in XML Schema, as I see that language mainly poised for
validation. I'm nervous about using that language for description
of data structures, in my opinion it's too powerful for that
task, with its <all>s and <sequence>s, with its <choice>s and
whatnot.
 AFAIK XML Schema is not even able to describe all the possible
structures in the XML data model (a tree), only a somewhat
restricted subset. I don't think going further would be
practical for XML Schema.
 Anyway, I'm not against using XML Schema simple data types, on
the other hand I think that higher-level data structures are too
application-specific.
 We can agree that NameValue pair (or KeyValue) is used often
where SOAP Encoding is used but I don't see in which way this
struct is special and so why it should be a part of SOAP
Encoding.
 Best regards,

                   Jacek Kopecky

                   Senior Architect, Systinet (formerly Idoox)
                   http://www.systinet.com/



On Fri, 21 Dec 2001, Noah Mendelsohn wrote:

 >
 > Whatever the implications for the SOAP design, I think you are somewhat
 > underestimating the reason for builtins such as positive integer in the
 > schema language.  Schema is NOT just used for validation.  It is equally
 > important as input to tools that do mappings to database languages,
 > programming languages, etc.  For these purposes, having well known and
 > agreed upon names for commonly used types is extremely important.
 > Otherwise, recognizing such types becomes a theorem proving exercise rather
 > than a simple recognition of type names (e.g. you would have to prove that
 > the facet restrictions on integer actually resulted in positive only.  If,
 > for example, someone restricted the lexical space to forbid minus signs,
 > that might do it, but I bet it would be a mess to detect.)
 >
 > I think there is an analogy for SOAP encoding.  Where we standardize well
 > known type names, tools are more likely to be able to generate effective
 > programming language mappings automatically.  On the other hand, having too
 > many such well-known types makes the spec too big, and tends to get us in
 > the business of defining types that are more special purpose.  I think the
 > NameValue and NameValueList types under discussion are in the grey area
 > where you can make a good case either way.   Thanks very much.
 >
 > ------------------------------------------------------------------------
 > Noah Mendelsohn                                    Voice: 1-617-693-4036
 > Lotus Development Corp.                            Fax: 1-617-693-8676
 > One Rogers Street
 > Cambridge, MA 02142
 > ------------------------------------------------------------------------
 >
 >
 >
 >
Received on Wednesday, 2 January 2002 13:44:35 GMT

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