Making enumerants be members of a class seems like the perfect application of existing RDFS constructs, and I don't see the syntax <s:maritalstatus rdf:resource="Single"/> any more burdensome than <s:maritalstatus>Single</s:maritalstatus> -- Mark Tom Van Eetvelde wrote: > Hello RDF comunity, > > I did some more thinking as I was not pleased with my own proposal to implement an enumeration of days. > > The core problem, I think, is the fact that the 'range' property only accepts classes. When validating > (or maybe better: typechecking), only instances of those classes may appear. This means that literals > can never be used as the instance must be typed, which means that it is a resource (with a 'type' > property)! This questions the use of literals in the RDF schema model. Literals can only be used for the > moment with properties that are not restricted in range. This makes the example 1 of the RDF M&S a bit > akward: what you would like to use is the following: > > <s:Person rdf:ID="Mike"> > <s:maritalstatus> Single </s:maritalstatus> > </s:Person> > > and not (the way we have to formulate it now): > > <s:Person rdf:ID="Mike"> > <s:maritalstatus rdf:resource="Single"/> > </s:Person> > > I currently believe that the most elegant way to introduce enumerations is to define a new > constraintproperty instance: 'literalRange'. This constraintproperty can only have 'bag' instances as > value. > > Continuing the 'days' example then: make a bag with all the days that you need. Make your property that > you want to see restricted to days and add to this property the literalRange = days bag. When making an > RDF instance using the defined property, the type checker can search for the filled-in value in the bag. > If it is in, validation = ok, else nok. > > Conclusion: the current defined 'RDF keywords' do not suffice to capture all kinds of behaviour that the > user wants. The current framework doesn't really support the use of literals when it comes to type > checking. > > Greetings, > > Tom. -- Mark Grossman Geocast Network Systems Tel: (650)566-3259 190 Independence Dr. Fax: (650)566-8112 Menlo Park, CA 94025 E-Mail: msg@geocast.comReceived on Tuesday, 26 September 2000 14:34:19 UTC
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