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Re: CURIE proposal ...

From: Sandro Hawke <sandro@w3.org>
Date: Tue, 22 Apr 2008 13:56:11 -0400
To: kifer@cs.sunysb.edu (Michael Kifer)
Cc: Axel Polleres <axel.polleres@deri.org>, "Public-Rif-Wg (E-mail)" <public-rif-wg@w3.org>
Message-ID: <27015.1208886971@ubuhebe>


> As I said, your proposal had a couple of holes, which Jos was trying to
> fix. Most of all, I do not like the fact that you are proposing that ":"
> would macro-expand differently depending on where it appears (after the ^^
> or elsewhere). My second proposal (<prefix:suffix>) was to fix that.

The problem with using "<" and ">" like this:

   In practice, URIs are delimited in a variety of ways, but usually
   within double-quotes "http://example.com/", angle brackets
   <http://example.com/>, or just by using whitespace:

      http://example.com/

   These wrappers do not form part of the URI.

(from RFC 3986 [1]), and the various Semantic Web specs all use <...> in
this way, to delimit URIs.   I think a good middle ground is something
like:

   1.  A "prefix" declaration syntax, as in Turtle:

         @prefix ns:   <http://example.org/ns#> .

       or SPARQL:

         PREFIX ns:   <http://example.org/ns#>

       or, maybe best, something more RIF-PS like:

         PREFIX("ns", "http://example.org/ns#").

   2.  The CURIE a:b syntax is the only syntax that can be used after
       the "^^" operator.   Eg:

         PREFIX("xs", "http://www.w3.org/2001/XMLSchema").
	 PREFIX("rif", "http://www.w3.org/2007/rif#").

         ... "10"^^xsd:integer ...
         ... "http://purl.org/dc/terms/creator"^^rif:iri

   3.  The CURIE a:b syntax MAY also be used as a shortcut for rif:iri
       terms, so givent his PREFIX declatation:

       	 PREFIX("dc", "http://purl.org/dc/terms/").

       the last term in #2 above could also be written as:

          ... dc:creator

I think that's all we really need to make IRI handling in the
presentation syntax relatively comfortable and precise, no?

           -- Sandro

(Note that it seems BLD has the wrong namespace for Dublin Core.  It
should be either "http://purl.org/dc/elements/1.1/" or
"http://purl.org/dc/terms/", with the latter being in some sense
preferred. [2].)

[1] http://www.ietf.org/rfc/rfc3986.txt
[2] http://dublincore.org/documents/dces/
Received on Tuesday, 22 April 2008 17:57:47 GMT

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