UPDATE: datatypes

		Datatypes in SWOL

	Peter F. Patel-Schneider
	Bell Labs Research
	(17 December 2001)


The semantics and syntax documents that I sent out contain a treatment of
datatypes that has the following features.

1/ Local datatyping syntax (and verification) can be handled by XML Schema
   verification.  In particular,
   
   <Person rdf:about="John">
     <age xsi:type="xsd:int">10</age>
   </Person>

   results in the age of John being the integer 10.

2/ Non-local datatyping can be handled by an additional interface to an XML
   Schema datatype processor.  In particular,

   <swol:Class rdf:about="Person">
     <rdfs:subClassof>
       <swol:toClass swol:property="age" swol:class="xsd:int" />
     </rdfs:subClassof>
   </swol:Class>

   <Person rdf:about="John" age="10" />

   results in the age of John being the integer 10.

3/ Other datatyping schemes are allowed.  That is, there is no requirement
   that XML Schema datatypes be used.  There is also the possibility of
   only using built-in XML Schema datatypes.


There are some problems and questions that remain, however, particularly
with respect to using XML Schema datatypes.

1/ How can constructed XML Schema datatypes be referenced?

2/ Who will build an XML Schema system that has the extra interfaces
   required by this way of handling datatypes?  There are a couple of
   tricky parts in the interface having to do with determining that the
   only possible denotation of a numeral as an integer is the usual one,
   and similar issues for the other datatypes.

3/ Will the RDF Core WG come up with a specification that is compatible
   with this general way of handling datatypes?




Action Items for the Clean-Up Task Force:

[Relevant comments from other WG members are welcome.]

1/ Determine if you disagree with the following:
   - The above is a reasonable way of handling datatypes in SWOL.
   - The above does not introduce other problems.

2 (optional)/ Make suggestions for improvements.

Schedule:

7 January 2002: final document for face-to-face discussion

Received on Monday, 17 December 2001 12:20:48 UTC