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Re: ISSUE-19: Should TURTLE allow triples like "[ :p 123 ]." as SPARQL does ?

From: Steve Harris <steve.harris@garlik.com>
Date: Sat, 2 Apr 2011 01:39:54 +0100
Cc: Peter Frederick Patel-Schneider <pfps@research.bell-labs.com>, andy.seaborne@epimorphics.com, richard@cyganiak.de, public-rdf-wg@w3.org, sysbot+tracker@w3.org
Message-Id: <5DB79DC1-8C01-4CA4-9B18-E530E707623A@garlik.com>
To: Alex Hall <alexhall@revelytix.com>
On 2011-04-01, at 16:45, Alex Hall wrote:

> On Fri, Apr 1, 2011 at 11:22 AM, Peter Frederick Patel-Schneider <pfps@research.bell-labs.com> wrote:
> From: Andy Seaborne <andy.seaborne@epimorphics.com>
> Subject: Re: ISSUE-19: Should TURTLE allow triples like "[ :p 123 ]." as SPARQL does ?
> Date: Fri, 1 Apr 2011 10:08:14 -0500
> 
> > http://www.w3.org/TR/sparql11-query/#grammar
> >
> > [21] TriplesBlock ::=
> >       TriplesSameSubject ( '.' TriplesBlock? )?
> > [32] TriplesSameSubject ::=
> >       VarOrTerm PropertyListNotEmpty | TriplesNode PropertyList
> > [34] PropertyList ::=
> >       PropertyListNotEmpty?
> > [38] TriplesNode ::=
> >       Collection | BlankNodePropertyList
> > [39] BlankNodePropertyList ::=
> >       '[' PropertyListNotEmpty ']'
> >
> > A lot of this is to exclude "[] ."
> >
> > http://www.sparql.org/query-validator.html ==>
> >
> > http://www.sparql.org/query-validator?query=PREFIX+%3A+%3Chttp%3A%2F%2Fexample%2F%3E%0D%0A%0D%0ASELECT+%3Fbook+%3Ftitle%0D%0AWHERE%0D%0A+++{+[+%3Ap+123+]+}%0D%0A&languageSyntax=SPARQL&outputFormat=sparql&linenumbers=true
> >
> >       Andy
> 
> 
> Ah, now I see it.  Tricky.
> 
> The extra complexity and lack of uniformity is a strong point against
> this syntax.
> 
> peter
> 
> I see your point here.  The name 'TriplesNode' implies a production that generates a [node, triples] tuple, so the triples always get added to the enclosing BGP and the node can be added to a surrounding triple context if present.  That is extra complexity, and doesn't allow you to write anything that you couldn't before.
> 
> But it does allow you to write statements about a blank node without having to give that node a label, even if nothing else in the graph refers to that node.  A common example from OWL:
> 
> [ a owl:AllDifferent; owl:distinctMembers (:a :b :c) ] .

I do think that we should add this form, but not for this reason, what's wrong with

   [] a owl:AllDifferent; owl:distinctMembers (:a :b :c) .

In this case?

- Steve

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Received on Saturday, 2 April 2011 00:40:35 GMT

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