W3C home > Mailing lists > Public > semantic-web@w3.org > January 2013

Re: SPIN Syntax simplified

From: David Booth <david@dbooth.org>
Date: Thu, 31 Jan 2013 11:45:23 -0500
To: Holger Knublauch <holger@knublauch.com>
Cc: semantic-web@w3.org
Message-ID: <1359650723.25867.16947.camel@dbooth-laptop>
Hi Holger,

On Thu, 2013-01-31 at 11:06 +1000, Holger Knublauch wrote:
> For those interested in SPIN, I have just published a blog post [1] that 
> introduces a fundamental change to the SPIN syntax. In a nutshell, too 
> many people have complained about the triple-based format to store 
> SPARQL queries. In the updated spec, the property sp:text can be used to 
> store the SPARQL query in textual form. This can happen either in 
> addition to the RDF syntax or alone. Existing SPIN files will of course 
> continue to work - the technical change to the spec was minimal.
> 
> I hope this change is in the best interest of the semantic web community 
> and leads to more SPIN implementations from other vendors than TopQuadrant.
> 
> Regards,
> Holger
> 
> [1] 
> http://composing-the-semantic-web.blogspot.com/2013/01/spin-syntax-simplified.html

That sounds like a good improvement.  And I think it would be great if
SPIN were standardized by W3C at some point.  But I have a question,
which I was not able to post on your blog because it does not allow
public comments.  

The example in the blog includes a CONSTRUCT as the quoted string value
of the spin:text property:

ex:Person a rdfs:Class ;
        ...
      spin:rule
              [ ...
                sp:text """
                    CONSTRUCT {
                        ?this ex:grandParent ?grandParent .
                    }
                    WHERE {
                        ?parent ex:child ?this .
                        ?grandParent ex:child ?parent .
                    }"""
        ...

I notice that the CONSTRUCT query above does not define the "ex:"
namespace prefix.  How are namespace prefixes handled inside the quoted
strings?  I.e., where/how are they defined?  Are there some other RDF
statements somewhere that explicitly define them?  Or are they magically
imported from the enclosing Turtle environment?  Or something else?


-- 
David Booth, Ph.D.
http://dbooth.org/

Aaron's Law, in memory of Web prodigy and open information 
advocate Aaron Swartz: http://bit.ly/USR4rx 

Opinions expressed herein are my own and do not necessarily 
reflect those of my employer.
Received on Thursday, 31 January 2013 16:45:52 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 21:45:53 GMT