W3C home > Mailing lists > Public > public-rdf-dawg@w3.org > April to June 2009

Re: Agenda 2009-06-16

From: Axel Polleres <axel.polleres@deri.org>
Date: Tue, 16 Jun 2009 00:08:21 +0100
Message-ID: <4A36D465.9030406@deri.org>
To: "Seaborne, Andy" <andy.seaborne@hp.com>
CC: 'RDF Data Access Working Group' <public-rdf-dawg@w3.org>
Seaborne, Andy wrote:
>> a) If we can find consensus, I would like to decide on publishing
>> http://www.w3.org/2009/sparql/docs/features/ as FPWD.
>> Particularly, if you CAN'T participate tomorrow and want to raise
>> concerns, please send them, if any possible before the Teleconf.
> 
> What's the status on these comments I've extract below:
> Key ones are:
> 
>   Non-mention of the time-permitting in F&R.[*]


Suggestion:
  cf. http://www.w3.org/2009/sparql/wiki/Features_Introduction_strawman
the sentence

"This current working draft details only the required features."

should be separate after the description (was hidden in the "status" 
bullet before, see
http://www.w3.org/2009/sparql/wiki/index.php?title=Features_Introduction_strawman&diff=894&oldid=892)


>   Negation is not syntax

Suggestion: 2 changes

"Hence, a new syntax is desired, as users requested, which the WG agrees 
with."
-->
"Hence, dedicated language constructs for expressing negation are 
desired, as users requested, which the WG agrees with."


"Yet, this syntax can be difficult to write and learn. Hence, the 
Negation feature to be included will provide the support for testing the 
absence of a match to a query pattern. "
-->
"Yet, this is not very intuitive to write and learn for users nor does 
it cater for efficient implementations of negation. Hence, the Negation 
feature to be included will provide the support for testing the absence 
of a match to a query pattern."



As for pointing to other implementations/syntaxes in order not to raise 
the impression to favor the MINUS syntax, I didn't find UNSAID at [1] 
but a pointer at [2] that UNSAID is supported by ARQ-with-extensions. If 
it is ok to refer to ARQ, we could just add the UNSAID example as well, 
i.e. we could add in the end of section 2.3.3

======================================================================
The same example using 
[http://tech.groups.yahoo.com/group/jena-dev/message/24828 ARQ's UNSAID 
extension]

  PREFIX foaf: <http://xmlns.com/foaf/0.1/>
  SELECT ?x
  WHERE { ?x foaf:givenName ?name
          UNSAID { ?x foaf:knows ?who }
        }
======================================================================


BTW: one more typo fix:

"The following example uses the SeRQL MINUS syntax to find the name of 
all people that does not no anyone, in a similar way to the previous query"
-->
"The following example uses SeRQL's MINUS syntax to find the names of 
all people that do not know anyone, in a similar way to the previous query"

Axel

1. http://jena.sourceforge.net/ARQ/extension.html
2. http://tech.groups.yahoo.com/group/jena-dev/message/24828

> For comments not going into the FPWD doc, could you indicate why, please.
> 
> 	Andy
> 
> [*] "View source" does not count.
> 
> 
> http://lists.w3.org/Archives/Public/public-rdf-dawg/2009AprJun/0346.html
> ----
> 2.2.2 but generally comment:
> 
> """
> That feature could be used, for instance, in the following use cases:
> """
> Not sure "could be used" is helpful without spelling out how it would be done, but that gets into far too much detail. Maybe just stick to the basic point.  
> ---
> 2.3: Negation.
> 
> "Hence, a new syntax is desired."
> 
> 
> The discussions so far have not been able just syntax.  The text implies to me that it is just syntax for writing OPTION/!BOUND.
> 
> The example of MINUS might be taken to imply that is the likely direction of the WG because it's the only example.
> 
> (mentioning SQL EXISTS has been done).
> 
> ----
> 2.4.3:
> 
> "though that might be unparseable or something along the lines of"
> Drifting into discussion?
> 
> --------
> The reply was: Kjetil:
>> Yeah, I don't like this myself. We should also have a review to ensure that we 
>> only have existing implementations here, and it this sounds like speculation.
> 
> 
> =================
> http://lists.w3.org/Archives/Public/public-rdf-dawg/2009AprJun/0346.html
> 
> ------------------
> Will the time-permitting features at least be mentioned?  Especially SPARQL/OWL.
> They don't need as much justification (IMO) - indeed for this publication, just placeholder structure is enough but something should go in.
> 
> Reply: Alex:
>> We've commented them from the TOC / Structure as we didn't have time  
>> to properly define it for the FPWD.
>> Yet, I just added the list of complete features in the introduction,  
>> which lists all of them.
> 
> I still think should list them even if that means empty sections.  It's about being complete to the community (the inline link to FeatureProposal does not count).
> 
> 
> ---
> == 2.4.2 Project expressions / Descriptions
> "ex:substring"
> 
> Use and example from XQuery/XPath F&O (e.g. fn:substring and strings are zero-based) to indicate we will reuse where possible. 
> ------------------
> == 2.4.3 Project expressions / Existing implementation
> 
> """
> This is also useful in CONSTRUCT:
> 
>  CONSTRUCT { ?x foaf:name (concat(?fn, " ", ?sn)) . }
>  WHERE { ?x foaf:firstName ?fn ; foaf:family_name ?sn . }
> """
> This is not a project expression!
> 
> Just keep the section clean and don't discuss CONSTRUCT.  Just need a direct discussion of project expressions.
> 
> 
> =============
> And new one:
> CONSTRUCT { ?x foaf:name ?name }
>  WHERE {
>    (SELECT concat(?fn, " ", ?sn) AS ?name
>     WHERE { foaf:firstName ?fn ; foaf:family_name ?sn . })
>  }
> 
> Suggest change (SELECT ) to {SELECT } as two implementations already do that.
> 


-- 
Dr. Axel Polleres
Digital Enterprise Research Institute, National University of Ireland, 
Galway
email: axel.polleres@deri.org  url: http://www.polleres.net/
Received on Monday, 15 June 2009 23:08:59 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 16:15:39 GMT