[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] RDF Schema Question: range of values of an rdfs:Class?
I will state my question, then give an example to demonstrate my question, and then restate my question. Question: if I create an RDF Schema Class, then what is its rdf:range of values? Example: In section 7 of the RDF Schema spec there are a number examples. My question pertains to Example 1. In Example 1 a Person Class is defined. A maritalStatus property is then defined and its domain property is set to Person (i.e., the maritalStatus property can be used with Person). The range of maritalStatus is the Class MaritalStatus. Here are the definitions: <rdfs:Class rdf:ID="Person"> <rdfs:comment>The class of people.</rdfs:comment> <rdfs:subClassOf rdf:resource="http://www.classtypes.org/useful_classes#Animal"/> </rdfs:Class> <rdf:Property ID="maritalStatus"> <rdfs:range rdf:resource="#MaritalStatus"/> <rdfs:domain rdf:resource="#Person"/> </rdf:Property> <rdfs:Class rdf:ID="MaritalStatus"/> In the example it says that the possible values for the maritalStatus property are: {Married, Divorced, Single, Widowed}. Here is where I have a question. How did the range of possible values for maritalStatus suddenly get restricted to these four values? In the example it creates four instances of the MaritalStatus Class: <MaritalStatus rdf:ID="Married"/> <MaritalStatus rdf:ID="Divorced"/> <MaritalStatus rdf:ID="Single"/> <MaritalStatus rdf:ID="Widowed"/> Presumably, this is where the four values were gotten from. Something seems fishy here. I am having difficulty relating this to my Java background. In Java, if I create a class MaritalStatus: public class MaritalStatus {...} then in another class create some instances of MaritalStatus: MaritalStatus married = new MaritalStatus(); MaritalStatus divorced = new MaritalStatus(); MaritalStatus single = new MaritalStatus(); MaritalStatus widowed = new MaritalStatus(); and now if I create a variable maritalStatus, of type MaritalStatus: MaritalStatus maritalStatus; then its range of possible values is not {married, divorced, single, widowed}. Certainly, maritalStatus can be set equal to one of these instance variables. For example: maritalStatus = married; However, it can take on values other than these as well. For example: maritalStatus = new MaritalStatus(); Okay, now that I've convinced myself that I don't understand the example in the RDF Schema spec, let me restate my question: how did that example come up with just those four values for the maritalStatus property? In general, if I create a Class, how do I specify its range of values? Cheers! /Roger xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev@i... Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/ and on CD-ROM/ISBN 981-02-3594-1 To (un)subscribe, mailto:majordomo@i... the following message; (un)subscribe xml-dev To subscribe to the digests, mailto:majordomo@i... the following message; subscribe xml-dev-digest List coordinator, Henry Rzepa (mailto:rzepa@i...)
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