- From: Jie Bao <baojie@cs.rpi.edu>
- Date: Wed, 14 Jan 2009 12:21:58 -0500
- To: "Seaborne, Andy" <andy.seaborne@hp.com>
- Cc: "Sandro Hawke" <sandro@w3.org>, "Axel Polleres" <axel.polleres@deri.org>, "Boris Motik" <boris.motik@comlab.ox.ac.uk>, "W3C OWL Working Group" <public-owl-wg@w3.org>
Hi Andy Thank you for your comment [1] on rdf:text [2]. Here is some my personal opinion on the issues you described. Other authors of the document may have further comments. Summary: In short, I believe your concern in mainly on the compatibility between rdf:text and the current specifications including RDF and SPARQL. I agree that rdf:text should not change the current specifications, explicitly or implied, nor have an impact on the behavior of existing tools that are designed to handle RDF. The wording of rdf:text should be changed to make this position clear. On the other hand, other syntaxes of OWL and RIF, without legacy issues, should be required to use rdf:text. =========== "Issue 1: systems that do understand rdf:text may represent information in RDF in two different ways that other RDF systems not upgraded to rdf:text will interpret in two different ways." I agree with your proposal that an RDF/XML implementation must abbreviate "xyz@lang"^^rdf:text into "xyz"@lang. In fact, Sandro had similar thoughts in a previous mail [3], which matches my belief so well that I quote it below "For simplicity of implementation, I think RDF serializations should mandate use of one style of language tagging or the other. In order to handle legacy syntaxes which were created before rdf:text and so could not pick, I think we should probably say rdf:text SHOULD NOT be used in any RDF syntax which has built-in support for language tagging (in order to avoid all the problems you name, below). That is, in RDF/XML, N-Triples, N3, and Turtle, one SHOULD NOT use rdf:text. (Happily, this aligns with rdf-syntax saying "Any other names are not defined and SHOULD generate a warning when encountered, but should otherwise behave normally.") Meanwhile, the various RIF syntaxes and the newer OWL syntaxes do not directly support language tagging, so one has to use rdf:text. Perhaps a Turtle 1.1 would remove type-a language tagging and mandate rdf:text instead. Similarly, APIs are free to pick one or the other (or some other, equivalent) approach, but should probably just provide one, and certainly not distinguish between the two." Thus, I propose to * make the two changes you suggested for this issue * add the following text to the end of the 1st paragraph of section 3. <A language syntax that does not directly support language tagging by RDF's plain literal with language tags, including but not necessarily limited to other OWL and RIF syntaxes, MUST use rdf:text as the datatype for internationalized strings> ================= "Issue 2: The treatment of xs:string is at odds with the current RDF specifications." I agree that in RDF the equivalence of "xyz" and "xyz"^^xs:string is semantically, but syntactical. Thus, the abbreviation suggested in the rdf:text spec should not imply that it introduces this change to the RDF syntax spec. In stead, in addition to your suggestions, we can add a note in 3.2 saying that <Note: the abbreviation of a literal of datatype xs:string is a consequence of the semantic equivalence of the abbreviated and original forms of the literal, as described by the RDF semantics [RDF Semantics]. > Please let me know if the suggested changes sufficiently address your concerns. I'm happy to further exchange ideas with you, and thank again for your constructive comments. [1] http://lists.w3.org/Archives/Public/public-owl-comments/2009Jan/0001.html [2] http://www.w3.org/TR/2008/WD-rdf-text-20081202/ [3] http://lists.w3.org/Archives/Public/public-rdf-text/2008OctDec/0028.html -- Jie http://www.cs.rpi.edu/~baojie
Received on Wednesday, 14 January 2009 17:22:36 UTC