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Re: CR Feedback and Implementation

From: Henry S. Thompson <ht@cogsci.ed.ac.uk>
Date: 18 Dec 2000 14:23:49 +0000
To: "Falk, Alexander" <al@altova.com>
Cc: www-xml-schema-comments@w3.org
Message-ID: <f5bn1dtajuy.fsf@cogsci.ed.ac.uk>
Thanks for your detailed comments.  Note for good public relations,
it's best not to send mail directly to both a public
(www-xml-schema-comments) and a member-only (w3c-xml-schema-ig) list
at the same time.

I'll respond to a few things I think we could use some clarification
on or where I think you've perhaps misunderstood something:

"Falk, Alexander" <al@altova.com> writes:

> 1) the CR should perhaps expressedly inform the reader, that any schema
> document that uses a default namespace (ie no prefix) to refer to
> "http://www.w3.org/2000/10/XMLSchema" must have a targetNamespace - otherwise
> any type="..." or ref="..." can not be correctly attributed to either the
> built-in types of XML schema or the types that the user defines in his/her
> schema

I'm not sure I understand.  The following is perfectly valid:

<schema xmlns="http://www.w3.org/2000/10/XMLSchema">
 <element name="foo">
  <sequence>
   <element name="bar" type="integer"/>
   <element name="baz" type="date"/>
  </sequence>
 </element>
</schema>

> 2) consider the question of non-deterministic content models with respect to
> local element declarations, e.g. in the following schema:
> 
> <?xml version="1.0" encoding="UTF-8"?>
> <!-- edited with XML Spy v3.5 NT beta 2 build Dec 11 2000
> (http://www.xmlspy.com) by Alexander Falk (Altova, Inc.) -->
> <xsd:schema xmlns:xsd="http://www.w3.org/2000/10/XMLSchema"
> elementFormDefault="qualified">
>         <xsd:element name="a">
>                 <xsd:complexType>
>                         <xsd:sequence>
>                          <xsd:element name="b" minOccurs="0" maxOccurs="unbounded">
                                     <xsd:complexType>  </xsd:complexType>
                           </xsd:element>
                           <xsd:element name="b" minOccurs="0" maxOccurs="unbounded">
                             <xsd:complexType> </xsd:complexType>
                           </xsd:element>
>                         </xsd:sequence>
>                 </xsd:complexType>
>         </xsd:element>
> </xsd:schema>
> 
> which declares two local elements <b> with different content models

<snip/>

> I would, therefore, recommend that the use of multiple locally declared
> elements with the same name within one parent are either discouraged or
> outright forbidden by the Schema specification.

Already outlawed!  See [1].

ht

[1] http://www.w3.org/TR/xmlschema-1/#cos-element-consistent
-- 
  Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh
          W3C Fellow 1999--2001, part-time member of W3C Team
     2 Buccleuch Place, Edinburgh EH8 9LW, SCOTLAND -- (44) 131 650-4440
	    Fax: (44) 131 650-4587, e-mail: ht@cogsci.ed.ac.uk
		     URL: http://www.ltg.ed.ac.uk/~ht/
Received on Monday, 18 December 2000 09:24:01 GMT

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