- From: <Patrick.Stickler@nokia.com>
- Date: Wed, 7 Nov 2001 09:59:56 +0200
- To: phayes@ai.uwf.edu, bwm@hplb.hpl.hp.com
- Cc: w3c-rdfcore-wg@w3.org
> The way of interpreting the > strings goes along with the class, not with the things in the > extension of the class. If we know that we are supposed to treat the > thing as being in a class which is a datatype class, then we know how > to interpret any literals that might denote it. Exactly. > That information is > associated with the class, not with the thing. Hence the Ntriples++ > triple: > > lit rdf:type <datatypeClass> . > > says exactly what it ought to say; eg > > "21" rdf:type xxd:octalNumber . > > tells us that the literal denotes 17, which is exactly what > > "17" rdf:type xxd:decimalNumber . > > also tells us. Although I agree with the spirit of the above statements, I am still a bit puzzled by the fact that the literal is acting as the subject. Surely we are not saying that all occurrences of the literal "21" are of type xxd:decimalNumber, are we? Rather, we are saying there is some value X that has a lexical form "17" and is of the type xxd:decimalNumber. I.e. #X rdf:value "17". #X rdf:type xxd:decimalNumber . The fusion of literal as subject really confuses me (an easy thing to do, I'll admit ;-) Subjects are resources which have unique global identity represented by a URI. Literals are not URIs, so how can they serve as subjects. If you are using the form "17" rdf:type xxd:decimalNumber . simply as a syntactic convenience, meaning that somewhere underneath that literal is in fact a node with globally (or at least system) unique identity, fine, but that is rather confusing IMO. After all, we are talking about a value here, not a given lexical form, and the value has both a type and lexical form, thus the anonymous node #X represents the value, not the literal. Eh? And so long as we must represent that value in terms of a lexical form, we need to have a consistent and persistent construct to tie form and type together which will endure across operations such as inferred binding to properties of superordinate or equivalent types. Thus we need to have that anonymous node (or some other encapsulation such as a URV encoding). Patrick
Received on Wednesday, 7 November 2001 03:00:07 UTC