- From: <Patrick.Stickler@nokia.com>
- Date: Tue, 13 Nov 2001 00:13:38 +0200
- To: phayes@ai.uwf.edu
- Cc: w3c-rdfcore-wg@w3.org
> -----Original Message----- > From: ext Patrick.Stickler@nokia.com > Sent: 12 November, 2001 22:47 > To: phayes@ai.uwf.edu > Cc: w3c-rdfcore-wg@w3.org > Subject: RE: Literals: lexical spaces and value spaces > > > > > >and one can end up with a literal value having a lexical > > >form that is not compatible with the data type of the > > >property. > > > > true, if the datayping information given in somehow incorrect. But > > the same can be said for a local type; if you give the > wrong datatype > > information, things will go wrong. You have such an example > above, in > > fact. What has that got to do with the local/nonlocal distinction? > > But if the type is determined by the rdfs:range constraint, > and the type is different between the original property of > the statement and some superordinate property that the literal > is bound to by inference, an error in interpretation can occur, > as one will be determining the data type by the range defined > for the superordinate property which may not have a compatible > lexical space. > > The literal may be unparsable or may be misinterpreted. > > Thus, given the data > > aaa ex:hexShoeSize "12" . > ex:hexShoeSize rdfs:subPropertyOf ex:shoeSize . > ex:hexShoeSize rdfs:range foo:hexInteger . > foo:hexInteger rdfs:subPropertyOf xsd:integer . Oops. That should have been foo:hexInteger rdfs:subClassOf xsd:integer . > ex:shoeSize rdfs:range xsd:integer. > > And a query > > aaa ex:shoeSize ?x . > > Which is satisfied as > -> x = "12" > > Which based on the knowledge > > ex:shoeSize rdfs:range xsd:integer > > Gets interpreted as > > int value = parseLiteral(xsd:integer,"12") > > value = 12 > > BOOM! (should be 18!) > > Eh? ;-) > > Thus, either literals must be bound to types locally, > or literals must be inseperable from their original > predicates. > > Both are satisified if statements are the basis for > interpretation and query binding. > > > >This, of course, presumes that we are not asserting the > > >global constraint on data types that the lexical space of > > >any data type must be a proper subset of the lexical space > > >of all of its superordinate types. > > > > Ah, but we must make that assumption; I have already conceded > > that point. > > But XML Schema simple data types fail that requirement. Thus, > we cannot make that assumption. Only value spaces for XML > Schema simple types are proper subsets of the value spaces > of their superordinate types. Lexical space is specific to > each type. I had hoped that was not the case, but it is. > > Patrick >
Received on Monday, 12 November 2001 17:14:00 UTC