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> -----Original Message-----
> From: Amelia A Lewis [mailto:amyzing@talsever.com]
> Sent: Monday, June 10, 2002 7:35 PM
> To: Aaron Skonnard
> Cc: 'Tim Bray'; xml-dev@lists.xml.org
> Subject: RE: [xml-dev] W3C Schema: Resistance is Futile, says Don Box
>
> The introduction of
> data types for "simple" (text nodes and
> attributes) nodes provides a way to validate the text, beyond
> existing parsed character data (the only valid type for text
> nodes in DTD), CDATA, Name, Token, NCName, QName, ID, IDREF,
> and the derived list types. Note that the attribute types
> are almost exclusively concerned with reference types (XML
> versions of pointers), and that at least two of them actually
> embed co-occurrence constraints (ID and IDRef), which cannot
> be modeled in any of the current schema languages, except by
> deus ex specificatia.
A.) I wouldn't call ID and IDREF co-occurrence constraints but instead
identity constraints of which W3C XML Schema has xs:key, xs:keyref and
xs:unique
B.) Schematron and to a lesser extent RELAX NG support co-occurrence
constraints.
--
PITHY WORDS OF WISDOM
The shortest distance between two points is under repair.
This posting is provided "AS IS" with no warranties, and confers no
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