- From: <noah_mendelsohn@us.ibm.com>
- Date: Mon, 25 Apr 2005 22:23:19 -0400
- To: "Thomas Li" <tli@corporola.com>
- Cc: www-xml-schema-comments@w3.org
A revised schema recommendation 1.1 is being prepared by the workgroup. As you can see in the draft available at [1], the lexical forms are indeed being described more formally using EBNF and regexps [2]. I suggest you look at some of the specific definitions therein. Of course, the schema datatypes provide value spaces along with lexical forms. Characteristics such as "order" are usually defined on the value spaces, and only indirectly on the lexical forms. So, the suggestion to use BNF for the lexical forms is a good one and is essentially being adopted. There are other important characteristics of the schema datatypes that are not well expressed using variations on BNF. Noah [1] http://www.w3.org/TR/2005/WD-xmlschema11-2-20050224/datatypes.html [2] http://www.w3.org/TR/2005/WD-xmlschema11-2-20050224/datatypes.html#Intro -------------------------------------- Noah Mendelsohn IBM Corporation One Rogers Street Cambridge, MA 02142 1-617-693-4036 -------------------------------------- "Thomas Li" <tli@corporola.com> Sent by: www-xml-schema-comments-request@w3.org 04/25/05 10:32 AM To: <www-xml-schema-comments@w3.org> cc: (bcc: Noah Mendelsohn/Cambridge/IBM) Subject: About Simple Types Comments: For XML Schema, I think it is equivalent to context free grammar, CFG. So the simple types should be regular expression for defining tokens in language, complex types should be BNF productions. Both regular expression and BNF or CFG are well defined and concise. Why don't we adopt and standardize them? The central task, I think, is to make XML schema shorter/concise and expressive as CFG using known terms. I have a feeling of standard/specification/recommendation and/or term explosion. Thank you for consideration. Thomas Li, Ph. D. Corporola Inc.
Received on Tuesday, 26 April 2005 02:23:36 UTC