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XQuery type system not integrated into the language

From: Bill Patton <bill.patton@cogneticsystems.com>
Date: Mon, 5 Aug 2002 11:20:46 -0400 (EDT)
Message-ID: <01C23C71.E99EE1B0.bill.patton@cogneticsystems.com>
To: "'public-qt-comments@w3.org'" <public-qt-comments@w3.org>


Although XQuery has many excellent features, its type system does not seem 
to be well integrated into the language.  Complex types can only be defined 
externally in  a different language called XML Schema.  We would hope that 
you consider designing a language that has a fully integrated type system.

To better understand the issues involved, we implemented an experimental 
version of XQuery that uses the type system described in the Formal 
Semantics document as its native type system.

The demo is located at http://www.cogneticsystems.com/xquery/xquery.html. 
 Our reasons for doing this are described at 

The demo displays both the static and dynamic types for query results. This 
is useful for observing what happens with the "assert as", "treat as", and 
"cast as" operators.  We have also implemented a "validate as" operator 
which validates XML content assigning types to its text nodes.  There are a 
 number of interesting queries listed under, "simple queries" and "type 
examples" on the web site.

Bill Patton
Cognetic Systems, Inc.
Received on Tuesday, 6 August 2002 14:14:59 UTC

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