- From: Harry Halpin <hhalpin@ibiblio.org>
- Date: Thu, 08 Jun 2006 23:50:08 +0100
- To: "Williams, Stuart (HP Labs, Bristol)" <skw@hp.com>
- Cc: Misha Wolf <Misha.Wolf@reuters.com>, www-tag@w3.org, public-rdf-in-xhtml-tf@w3.org, newsml-2@yahoogroups.com
Quick note - One of the objections to microformats is their lack of a namespaces. RDF/A overcomes this by using "role" and so on attributes, but the traditional answer being put forward by the hCal and hCard folks is that they can't use namespaces within a class attribute of a div or span element precisely because that would break CSS's use of the colon, such that this <span class="vCard:Country">UK</span> is broken in CSS. So perhaps if there is to be some "next generation" CURIE that is a superset of QNames, using some other arbitrary character *besides the colon* would be a good idea, giving the microformat people "namespaces for free" as long as they use the "next generation" CURIE and therefore giving this spec a sort of instant user community. cheers, harry Williams, Stuart (HP Labs, Bristol) wrote: > Hello Misha, > > FWIW... a colleague suggested the use of '::' to separate prefix from > suffix ie. prefix::suffix > > Rationale: > 1) Visually/Syntactically distinct from QNames. > 2) Appealingly similar in appearance to QNames. > > Regarding 7(a-h) below: > This seems to me to leave far too many things open for each language > using CURIEs to have to specify - making it difficult to conceive of > generic libraries for handling CURIEs. In particular: > > 7a) there should only be one set of syntactic constraints; > 7b) see '::' suggestion above > 7d) *if* CURIEs are genuinely a compact way of writing a URI, there > should be a *single* mapping from a CURIE to a URI/IRI. > 7e) should have a single answer... which probably (regrettably) means a > CURIE is a tuple of {prefix, suffix, prefixURI, compactedURI} > 7f-g) seems like normal good practice with URIs applies any CURIE spec. > should remain silent. > 7h) again surely a matter for generic URI/IRI syntax. > > Fixing all of that would leave solely the matter of establish a > prefix=>URi mapping on a per language basis (7c), and I would hope there > would be a single approach for XML based languages - other non XML based > languages (N3 (and friends), SPARQL...) would have to define their own > mechanisms. > > 8b) seems troubling because it risks confusing a Qname with a CURIE. > > Just my 2 cents. > > Regards > > Stuart > -- > > > >> -----Original Message----- >> From: www-tag-request@w3.org [mailto:www-tag-request@w3.org] >> On Behalf Of Misha Wolf >> Sent: 02 June 2006 19:14 >> To: www-tag@w3.org >> Cc: public-rdf-in-xhtml-tf@w3.org; newsml-2@yahoogroups.com >> Subject: CURIEs: A proposal >> >> >> Hi folks, >> >> A modest proposal, drawing on ideas from Mark, Henry, Tim, >> Dan, Norm and others: >> >> 1 We agree on a generic syntax and generic rules for Compact URIs >> (CURIEs) in attribute values. >> >> 2 We agree that restricted syntaxes and rules will be (or have >> been) defined for specific purposes. One such purpose is XML >> Namespaces and QNames. >> >> 3 Groups within the W3C and elsewhere will define other restricted >> syntaxes and rules for their own purposes. >> >> 4 The generic syntax for a CURIE in an attribute value will be: >> <foo bar="prefix:suffix"/> >> >> 5 The generic syntax for multiple CURIEs in an attribute value >> will (where permitted) be: >> <foo bar="prefix1:suffix1 ... prefixN:suffixN"/> >> >> 6 Both the prefix and the suffix may (in the generic case) be >> numeric. >> >> 7 Each language must specify: >> >> 7a the syntactic constraints (if any) on the prefix and suffix. >> >> 7b how CURIEs and URIs are distinguished, eg through dedicated >> attributes or through a special syntax. >> >> 7c the mechanism for specifying the prefix-to-IRI mapping. The >> mechanism may use information provided out-of-band. >> >> 7d whether and, if so, how the prefix and suffix are combined to >> form an IRI. >> >> 7e whether the prefix and suffix form a tuple or whether they are >> just a compact representation for an IRI. >> >> 7f whether the IRI mapped to the prefix is required to be >> dereferenceable. >> >> 7g whether the IRI built from the prefix and suffix (and, possibly, >> including also other building blocks) is required to be >> dereferenceable. >> >> 7h whether any fragment identifiers in these IRIs are required to >> be legal XML names. >> >> 8 To avoid confusion with XML Namespaces and QNames: >> >> 8a The xmlns attribute is reserved for use with XML Namespaces and >> QNames. >> >> 8b If a prefix matches an xmlns declaration then the CURIE MUST be >> interpreted as a QName. >> >> Misha >> ------------------- NewsML 2 resources ------------------------------ >> http://www.iptc.org | http://www.iptc.org/std-dev/NAR/1.0 >> http://www.iptc.org/std-dev | http://groups.yahoo.com/group/newsml-2 >> >> >> To find out more about Reuters visit www.about.reuters.com >> >> Any views expressed in this message are those of the >> individual sender, except where the sender specifically >> states them to be the views of Reuters Ltd. >> >> >> >> > > -- -harry Harry Halpin, University of Edinburgh http://www.ibiblio.org/hhalpin 6B522426
Received on Friday, 9 June 2006 03:49:30 UTC