Version 1.4 of XSV Released

Date:      12 Nov 2001 15:36:30 +0000
From:      "Henry S. Thompson" <ht@cogsci.ed.ac.uk>
To:        xmlschema-dev@w3.org, xml-dev@lists.xml.org
Subject:   Version 1.4 of XSV released: derivation-by-restriction experiment

The web interface [1], the self-installer [2] and the sources [3] for XSV, our W3C XML Schema validator, have all been updated with a new version.

"Version 1.4 introduces a cheap-but-effective approximation to enforcement of the constraints on derivation by restriction for complex type definitions. This works by enforcing the subset invariant, and rejects any content model for a type definition derived by restriction which allows anything not allowed by the base type definition's content model. This is slightly weaker than the REC: i.e., everything it rules out is ruled out by the REC, but a few things ruled out by the REC will not be caught."

Note this is not what the REC envisages, but it will go a lot further towards enforcing interoperability between XSV and other processors which do enforce the REC as intended.

Nothing is as good as full conformance, but I hope this step, which only took about three hours to implement, will be of use never-the-less.

As with any substantial change, there may be bugs lurking -- I'll fix them as quickly as possible provided bug reports contain enough information to reproduce the bugs.

[1] http://www.w3.org/2001/03/webdata/xsv
[2] ftp://ftp.cogsci.ed.ac.uk/pub/XSV/XSV14.EXE
[3] http://dev.w3.org/cvsweb/xmlschema/ -- see
    http://www.ltg.ed.ac.uk/~ht/xsv-status.html
    for installation instructions

   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/

Prepared by Robin Cover for The XML Cover Pages archive. See "XML Schemas."

SEARCH Advanced Search ABOUT Site Map CP RSS Channel Contact Us Sponsoring CP About Our Sponsors NEWS Cover Stories Articles & Papers Press Releases CORE STANDARDS XML SGML Schemas XSL/XSLT/XPath XLink XML Query CSS SVG TECHNOLOGY REPORTS XML Applications General Apps Government Apps Academic Apps EVENTS LIBRARY Introductions FAQs Bibliography Technology and Society Semantics Tech Topics Software Related Standards Historic	Version 1.4 of XSV Released Date: 12 Nov 2001 15:36:30 +0000 From: "Henry S. Thompson" <ht@cogsci.ed.ac.uk> To: xmlschema-dev@w3.org, xml-dev@lists.xml.org Subject: Version 1.4 of XSV released: derivation-by-restriction experiment The web interface [1], the self-installer [2] and the sources [3] for XSV, our W3C XML Schema validator, have all been updated with a new version. "Version 1.4 introduces a cheap-but-effective approximation to enforcement of the constraints on derivation by restriction for complex type definitions. This works by enforcing the subset invariant, and rejects any content model for a type definition derived by restriction which allows anything not allowed by the base type definition's content model. This is slightly weaker than the REC: i.e., everything it rules out is ruled out by the REC, but a few things ruled out by the REC will not be caught." Note this is not what the REC envisages, but it will go a lot further towards enforcing interoperability between XSV and other processors which do enforce the REC as intended. Nothing is as good as full conformance, but I hope this step, which only took about three hours to implement, will be of use never-the-less. As with any substantial change, there may be bugs lurking -- I'll fix them as quickly as possible provided bug reports contain enough information to reproduce the bugs. ht [1] http://www.w3.org/2001/03/webdata/xsv [2] ftp://ftp.cogsci.ed.ac.uk/pub/XSV/XSV14.EXE [3] http://dev.w3.org/cvsweb/xmlschema/ -- see http://www.ltg.ed.ac.uk/~ht/xsv-status.html for installation instructions 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/ Prepared by Robin Cover for The XML Cover Pages archive. See "XML Schemas."