On 21.12.20 12:21, Andy Seaborne wrote:
>
>
> On 21/12/2020 07:47, Lorenz Buehmann wrote:
>>
>> On 20.12.20 17:19, Andy Seaborne wrote:
>>>
>>>
>>> On 20/12/2020 09:20, Lorenz Buehmann wrote:
>>>>
>>>> On 19.12.20 21:14, Laura Morales wrote:
>>>>> Is this
>>>>>
>>>>> << :a :b :c >> :d ; :e .
>>>>>
>>>>> the equivalent of this?
>>>>>
>>>>> << :a :b :c >> :d .
>>>>> << :a :b :c >> :e .
>>>>>
>>>>> Will Fuseki/Jena store them and treat them the same exact way?
>>>> https://w3c.github.io/rdf-star/rdf-star-cg-spec.html#turtle-star-grammar
>>>>
>>>
>>> Yes - there is no changes to Turtle except to add <<>> as a new kind
>>> of RDF term. For syntax, the new annotation syntax (in issue 9) is
>>> likely to happen and is a way to write <<>> and assert the triple in
>>> one form.
>>
>> Yep - something that I think might be confusing for people start using
>> RDF* might be the fact that
>>
>> << :a :b :c >> :d .
> >
>> is just an annotation but doesn't add the triple itself.
>
> << :a :b :c >> :d "object" .
>
> is a triple. It is a triple about another ":a :b :c" These <<>> things
> behave like literals in the sense that their representation tells you
> everything you need to know about them.
>
> The subject is the (new) RDF term << :a :b :c >>.
I might have been unclear - that was exactly my point: it does not add
the triple itself but "talks" about the other triple, i.e. <:a :b :c> in
G is false.
People have to be aware of this fact and should use the new annotation
syntax in case the want to add both the fact and the annotation about it
in one step - this should heavily be mentioned in the final specs. But
I'm sure you guys are already aware of this fact.
>
>> I'm also
>> wondering how triple stores will handle this if the triple itself
>> doesn't exist
>
> << :a :b :c >> is a new kind of Node in Jena (Node_Triple).
>
>> - will it simply be dropped after parsing the whole
>> document is done? Given that the triple could occur after the annotation
>> in a stream, this needs some more effort for triple stores, right?
>
> Not in Jena the <<>> is a new RDF Term (node) and is a first-class
> object in the system. It does not need triple ":a :b :c" to exist.
>
> Annotations are not stored directly with the triple they annotate.
> There is an indirection through the <<>> term.
>
>> Also,
>> what happens if a SPARQL INSERT does add just the annotation? I guess
>> nothing, or will the annotation be kept nevertheless - I don't think so?
>>
>> On the other hand, the annotation syntax will add both, the triple and
>> the annotation in a step - this is nice.
>
> For our readers: this is annotation syntax:
>
> :a :b :c {| :d "object" |}
>
> it is syntax for two triples:
>
> :a :b :c .
> << :a :b :c >> :d "object" .
>
> Modelling in the data is used for complex use cases -
> Here is a larger example where we have two separate sources for a triple:
>
> PREFIX : <http://example/>
> PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
>
> :s :p :o {| :source [ :graph <http://host1/> ;
> :date "2020-01-20"^^xsd:date
> ] ;
> :source [ :graph <http://host2/> ;
> :date "2020-12-31"^^xsd:date
> ]
> |} .
>
> It is:
>
> @prefix : <http://example/> .
> @prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
>
> :s :p :o .
>
> << :s :p :o >>
> :source [ :date "2020-12-31"^^xsd:date ;
> :graph <http://host2/>
> ] .
> << :s :p :o >>
> :source [ :date "2020-01-20"^^xsd:date ;
> :graph <http://host1/>
> ] .
>
> or (same triples)
>
> << :s :p :o >>
> :source [ :date "2020-12-31"^^xsd:date ;
> :graph <http://host2/>
> ] ;
> :source [ :date "2020-01-20"^^xsd:date ;
> :graph <http://host1/>
> ] .
>
> Like every use of "1"^^xsd:integer or <http://example/> is the same
> RDF term (and unliek the []-syntax) , every use of <<:s :p :o>> is the
> same term.
>
> Andy
>
>>
>>>
>>> Everything else is left untouched.
>>>
>>> ";" and "," are just syntactic sugar in Turtle.
>>>
>>> How the triples are written makes no difference - a graph is a set of
>>> triples.
>>>
>>> Syntax test suite:
>>>
>>> https://w3c.github.io/rdf-star/tests/turtle/syntax/manifest.html
>>>
>>> Andy
