- From: Mark Birbeck <mark.birbeck@x-port.net>
- Date: Sat, 7 Jan 2006 20:20:30 -0000
- To: <public-rdf-in-xhtml-tf@w3.org>
Hi everyone, I hope you all had good breaks, and happy new year. As part of looking at RulesML [1] I was reading a W3C member submission called "Web Rule Language (WRL)" [2] and came across this: An IRI can be abbreviated to an sQName. Note that the term 'QName' has been used, after its introduction in XML [XMLNamespaces], with different meanings. The meaning of the term 'QName' as defined in XML got blurred after the adoption of the term in RDF. In XML, QNames are simply used to qualify local names and thus every name is a tuple <namespace, localname>. In RDF, QNames have become abbreviations for URIs, which is different from the meaning in XML. WRL adopts a view similar to the RDF-like version of QNames, but due to its deviation from the original definition in XML we call them sQNames which is short for 'serialized QName'. This is exactly the motivation we have for CURIEs--that the definitions have become blurred. The only thing I would disagree with the authors on is that the use of 'QNames' in RDF should be blamed--it's hard to find a W3C spec that *isn't* using QNames inappropriately! What also really caught my eye was that the document goes on to present a different syntax to the normal 'QNames' one: An sQName consists of two parts, namely, the namespace prefix and the local part. WRL allows two distinct ways to write sQNames. sQName can be seen as a datatype and thus it has an associated datatype wrapper, namely, _sqname (see also Appendix A), which has two arguments: namespace and localname. Because sQNames are very common in WRL specifications, WRL allows a short syntax for sQNames. An sQName can simply be written using a namespace prefix and a localname, separated by a hash ('#'): namespace_prefix#localname. It is also possible to omit the namespace prefix and the hash symbol. In this case, the name is defined in the default namespace. I'm not suggesting that we stray from using the colon as the separator--I just thought it was interesting that they have chosen to avoid the QName syntax altogether, and it might provoke some thoughts. Regards, Mark [1] www.ruleml.org/spec [2] http://www.w3.org/Submission/WRL/ Mark Birbeck CEO x-port.net Ltd. e: Mark.Birbeck@x-port.net t: +44 (0) 20 7689 9232 w: http://www.formsPlayer.com/ Download our XForms processor from http://www.formsPlayer.com/
Received on Saturday, 7 January 2006 20:21:04 UTC