- From: <Patrick.Stickler@nokia.com>
- Date: Mon, 5 Nov 2001 11:27:24 +0200
- To: connolly@w3.org
- Cc: w3c-rdfcore-wg@w3.org
> -----Original Message----- > From: ext Dan Connolly [mailto:connolly@w3.org] > Sent: 05 November, 2001 10:39 > To: Stickler Patrick (NRC/Tampere) > Cc: w3c-rdfcore-wg@w3.org > Subject: Re: Reject change to rdf:value > > > Patrick.Stickler@nokia.com wrote: > > > > > Well, if that were indicated by a decimal then the > > > string "10" would do it, but if it were represented by an > octal then > > > you need "12" and if you use a binary then you need > "1010". There is > > > no way to say what THE value of rdf:value is for any particular > > > integer, until you specify what datatyping scheme is being used. > > > > No. Data type does not define lexical representation, > > In the context of this WG, it does... Yes. Quite right. I was meaning to say that the value space of a given data type is not necessarily tied to a given lexical representation, and thus, if we are intending to use e.g. xsd:integer to refer to the value space, then we must employ other mechanisms to address any lexical representational qualities, such as base notation, as the value space defined by 'xsd:integer' has no dependencies on such things. Of course, XML Schema *does* say what the lexical representation of XML serialized content data must be which are supposed to define xsd:integer values, and to that end, base representations other than 10 are not allowed, so a base 2 (binary) value "1010" is an invalid xsd:integer lexical form and the serialization <xsd:integer>1010</xsd:integer> is invalid. So, perhaps the question is whether, in the RDF encoded knowlege base, are *both* the value space and the lexical constraints implied when one assigns the rdf:type of 'xsd:integer' to a given RDF literal? If the answer is 'yes', then one is not free to employ other lexical representations and one must then either abide by the lexical constraints as defined or define another data type which allows/supports the desired lexical form. Now, we can define a taxonomy of data types which includes several notational variants of a given value space, such as integer hexInteger octInteger binInteger etc. But I think we will run into problems there. For e.g. 'hexInteger' to be a subClass of integer, that (at least to me) implies that any valid hexInteger value is also a valid integer value, and is a specialization of integer. Unfortunately, that is not the case for either point. A hexInteger lexical form is not a valid integer lexical form and a hexInteger is not a specialized form of integer (as is e.g. a nonNegativeInteger). Thus, I see the only reasonable solution being either to "toe the line" with regards to the lexical forms defined for a given data type, or come up with a mechanism by which data types can be declared as "equivalent" insofar as the value space is concerned but not necessarily with regards to their lexical representations. Thus what we then end up with is integer ~ hexInteger ~ octInteger ~ binInteger Though that seems rather kludgy to me... Cheers, Patrick -- Patrick Stickler Phone: +358 50 483 9453 Senior Research Scientist Fax: +358 7180 35409 Nokia Research Center Email: patrick.stickler@nokia.com
Received on Monday, 5 November 2001 04:27:42 UTC