W3C home > Mailing lists > Public > public-rdf-dawg-comments@w3.org > May 2005

Re: User defined operations and PREMISES keyword

From: Dan Connolly <connolly@w3.org>
Date: Thu, 12 May 2005 09:36:49 -0500
To: Stephane Fellah <stephanef@imagemattersllc.com>, public-rdf-dawg-comments@w3.org
Message-Id: <1115908609.13402.394.camel@localhost>

Your message of 20 Apr continues...
http://lists.w3.org/Archives/Public/public-rdf-dawg-comments/2005Apr/0038.html

> ISSUE 3: DESCRIPTION OF SUPPORTED FUNCTIONS IN SPARQL PROTOCOL.
>
> The SPARQL <http://www.w3.org/TR/rdf-sparql-protocol/>  Protocol for RDF
> document is not clear how the ServiceDescription describes the supported
> functions and operations by the SPARQL Service. 
>
> For client operations, it is important not only to know the URI of the
> functions and operations but also to get a description of their arguments
> types, cardinality  and order.

Hmm... it's clear to me that a client might recognize the URI of
an extension function, and hence know its purpose/functionality,
as well as its signature (arg types etc). It's hard for me to 
imagine a client that can dynamically make use of just the
signature information. Can you give an example, please?

In any case...

> An additional optional query type could be added to describe Functions and
> Operands such GetOperationDescription and takes an optional parameter name
> which can take a list of operand or function uri,
> 
> http://www.foo.com/sqs?query=GetOperationDescription&name=http://my.example.
org/geo/functor#WithinDistance, http://my.example.org/geo/functor#Intersects
>
> The response should be in RDF format. This assumes an ontology for functors
> and operands needs to be elaborated.

Do you have a design for such an ontology handy? The WG has not discussed
service descriptions that go into that level of detail.


> In conclusion, I would like the DAWG elaborates more the section 11.3 of the
> current SPARQL Query Language for RDF document, because I anticipate many
> user-defined functions would be defined in the future. 

OK, yes, stay tuned for future drafts. We're working on it.

-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
D3C2 887B 0F92 6005 C541  0875 0F91 96DE 6E52 C29E
see you at XTech in Amsterdam 24-27 May?
Received on Thursday, 12 May 2005 14:36:59 GMT

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