- From: Henry S. Thompson <ht@cogsci.ed.ac.uk>
- Date: 12 Sep 2000 12:51:59 +0100
- To: Bob Schloss <rschloss@us.ibm.com>
- Cc: www-xml-schema-comments@w3.org
You posted a contribution to the XML Schema comments list on 10 May, which was assigned the ID LC-112 [1]. We are currently working through all comments we've received on XML Schema to ensure they have been adequately dealt with, and are embarassed to find you have so far received no reply. The Unique Attribution constraint is intended to reconstruct as nearly as possible the equivalent constraint in XML 1.0 [2]. As such it applies entirely at the level of (qualified) element names: the matter of types is addressed separately, by the Element Declarations Consistent constraint [3], which forbids two elements with the same name but different type from appearing in a content model at all. We have use the name "Unique Attribution constraint", not "Determinism constraint", because it does not rule out all non-deterministic models, e.g. (a|b?)*. Following comments from you and others, we have reworded the Unique Attribution constraint as follows: A content model must be formed such that during schema validation of an element information item sequence, the particle contained directly, indirectly or implicitly therein with which to attempt to schema-validate each item in the sequence in turn can be uniquely determined without examining the content or attributes of that item, and without any information about the items in the remainder of the sequence. A formal specification in terms of finite-state automata has also been added to the discussion in Appendix F. Could you confirm that this modification and the discussion above addresses your concerns to your satisfaction? Thanks ht [1] http://www.w3.org/XML/Group/xmlschema-current/lcissues.html#determinism [2] http://www.w3.org/TR/REC-xml#determinism [3] 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 Tuesday, 12 September 2000 07:52:02 UTC