- From: Michael McCaleb <mccaleb@eeel.nist.gov>
- Date: Fri, 15 Dec 2000 17:03:42 -0500
- To: www-xml-schema-comments@w3.org
Dear XML Schema editor, Observation: In doing a comparison between the EXPRESS data modeling language (ISO 10303-11) and XML Schema, I noticed that in EXPRESS it is possible to create a subtype that both is a restriction (e.g., attribute value range restriction) of its supertype and an extension (e.g., an addition of another attribute) of its supertype. From the expressions for simpleContent complexContent (see below) it appears that in order to do the same thing in XML Schema that in intermediate throw away subtype would need to be created. <simpleContent id = ID {any attributes with non-schema namespace . . .}> Content: (annotation? , (restriction | extension)) </simpleContent> <complexContent id = ID mixed = boolean {any attributes with non-schema namespace . . .}> Content: (annotation? , (restriction | extension)) </complexContent> Question: Would it be worthwhile to permit both restriction and extension to be in the same simpleContent and complexContent. Sincerely, Mike McCaleb
Received on Friday, 15 December 2000 17:02:21 UTC