Schema NUNs

Schema Normalized Universal Names (draft at [1]) is soon to be published
as a W3C Note.

In reviewing this document, I first notice that Schema NUNs are relative
to a particular schema.  They are not relative to a target namespace.
The Use Cases given don't seem to make this distinction; that is, NUNs
can be used by RDF statements to talk about a particular schema, but
there is no explicit use case of talking more abstractly about a target
namespace.  Which do we want to identify for WSDL?

Schema NUNs are compatible with XPointer.  A new fragment scheme
xs-nun() uses an XPath-like syntax to distinguish the various symbol
spaces and navigate the hierarchy of schema components (just as XPath
distinguishes node types and names and hierarchy).

Here is an example of a schema NUN (on multiple lines for readability):

  http://www.example.com/schemas/po.xsd#
    xmlns(po=http://www.example.com/PO1)
    xs-nun(/complexType(po:Items)/sequence()/item)

Note that the syntax identifies constructs relative to a QName in the
"complexType" symbol space.

A corresponding WSDL identification mechanism might look something like:

  http://www.example.com/wsdl/myticketagent.wsdl#
    xmlns(ta=http://www.airline.wsdl/ticketagent/)
    wsdl(/portType(ta:TicketAgent)/
          operation(listFlights)/
          input(listFlightsRequest))

Arthur's proposal looks more like this:

  urn:wsdl:http://airline.wsdl/ticketagent/#
    input(TicketAgent/listFlights/listFlightsRequest)

These are just syntax differences.

[1]
http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2002Oct/att-0050/0
1-part

Received on Monday, 4 November 2002 18:19:42 UTC