Re: is/of feature of N3 in turtle/sparql?

On Sat, May 28, 2005 at 03:47:50PM -0400, Stan Devitt wrote:
> Just to be perfectly clear, 
> 
> the key point I want to raise is that  at the moment depending on how "is" 
> aliased, the statement  ":a is :b of :c."  may or may not
> parse.  Similarly for   ":a is :b."    The "is" tokens in the two 
> statements play entirely different roles. 
> 
> I am commenting specfically on n3 at the moment and need to look at the 
> use on SPARQL before commenting further, other
> than indicating my preference to avoid applying aliasing at tokenization 
> time.

The relevent part of the SPARQL grammar is at
  <http://www.w3.org/2001/sw/DataAccess/rq23/#rTriples1>

The grammar currently inludes:
  . , ;
    s p o . s p o2
    s p o, o2
    s p o; p o2
  [] ()
    [] p o
    [ p o ]
    s p ( i1 i2 )

My opinion as both an editor and working group member is that the
turtle syntax is intuitive and attractive in its simplicity. We have
postponed a number of issues for later versions of the language. I
would postpone the expansion of the graph language to include more of
n3 such as:
  s >- p -> o	# now  s = p => o  ?
  o <- p -< s	# now  o <= p = s  ?
  o is p of s
  has		# which i don't understand. where's the object?
  this
  =		# for owl:sameAs
  is		# without the of
  and the ever-controversial {}


> Stan Devitt
> 05/28/2005 03:24 PM
> 
> 
>         To:     Danny Ayers <danny.ayers@gmail.com>
>         cc:     Dan Connolly <connolly@w3.org>, "Eric Prud'hommeaux" <eric@w3.org>, 
> public-cwm-talk@w3.org, public-cwm-talk-request@w3.org
>         Subject:        Re: is/of feature of N3 in turtle/sparql?
> 
> There are two important things to note:
> 
> 1.  The current n3 grammar defines this four term structure in terms of 
> the tokens @is and @of.  This re-interpretatation in terms of "is" and 
> "of" relies on
> aliasing.
> 
> 2.  Because  @is and @of participate in a very different grammatical 
> structure from (say) simple name tokens this complicates the aliasing 
> mechanism considerably.  There is now more than one possible grammatical 
> role for the target of the alias so the actual tokenizing is changed by 
> the aliasing. 
> 
> I would be happier if either aliasing were not involved, or at least did 
> not change the tokenizing.  Can someone comment on this? 
> 
> Stan Devitt
> Agfa 
> 
> 
> 
> 
> 
> Danny Ayers <danny.ayers@gmail.com>
> Sent by: public-cwm-talk-request@w3.org
> 05/28/2005 05:03 AM
> Please respond to Danny Ayers
> 
>  
>         To:     Dan Connolly <connolly@w3.org>
>         cc:     public-cwm-talk@w3.org, "Eric Prud'hommeaux" <eric@w3.org>, (bcc: Stan 
> Devitt/AWKCT/CAN/AGFA/CA/BAYER)
>         Subject:        Re: is/of feature of N3 in turtle/sparql?
> 
> 
> 
> Dan, I've still not spent any proper time with cwm (for shame!), could
> you please just clarify is/of:
> 
> * It's a convenience rather than introducing anything new? 
> 
> * Would this be correct -
> 
> select ?x where
> {
> :EricDoc dc:creator ?x
> }
> 
> select ?x where
> {
> ?x is dc:creator of :EricDoc
> }
> 
> would produce the same results?
> 
> Cheers,
> Danny.
> 
> 
> On 5/28/05, Dan Connolly <connolly@w3.org> wrote:
> > 
> > I just realized the other day that SPARQL doesn't have is/of,
> > nor does turtle...
> > 
> > 22:48:25 <DanC> ^sparqlquery select ?pg where { [ foaf:nick "DanC"] is
> > cyc:socialParticipants of [ contact:homePage ?pg] }
> > 22:48:25 <julie> Bad query (SPARQL syntax error at 'i')
> > 22:48:38 <dajobe> that's not in sparql - is, of
> > 22:48:38 <DanC> oh frap. no is/of in SPARQL
> > http://www.ilrt.bris.ac.uk/discovery/chatlogs/swig/2005-05-19.html#T22
> > -48-25
> > 
> > Hmm.
> > 
> > I'm hoping the WG will close all the remaining issues, including
> > http://www.w3.org/2001/sw/DataAccess/issues#punctuationSyntax ,
> > in the next week or so. In particular, punctuiationSyntax is pretty
> > much all set to go this Tuesday. So it would be good to get feedback
> > on this right away. In particular, if you want is/of in, send
> > something to public-rdf-dawg-comments@w3.org .
> > 
> > refs:
> > 
> > N3 primer, on is/of etc. http://www.w3.org/2000/10/swap/Primer
> > SPARQL http://www.w3.org/TR/rdf-sparql-query/
> > turtle http://www.ilrt.bris.ac.uk/discovery/2004/01/turtle/
> > 
> > 
> 
> 

-- 
-eric

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