Re: Annotation syntax [was: SPARQL* test suite]

On 02/09/2020 09:04, Olaf Hartig wrote:
> Dear all,
> 
> I am intrigued by the idea to add a second option to the Turtle* syntax such
> that PG mode and SA mode can be explicitly distinguished from one another. In
> fact, now I wonder whether such a distinction can even be built into the RDF*
> data model (it can, see below).
> 
> The only issue with this new "PG mode option" for Turtle* is that it works
> only for annotations that have the annotated triple in the subject position.
> Take, for instance, Holger's example:
> 
>> ... instead of
>>
>>       :bob :age 23 .
>>       <<:bob :age 23>> :certainty 0.9 .
>>
>> we can simply (alternatively) write
>>
>>      :bob :age 23 {| :certainty 0.9 |} .
> 
> That works. However, the following Turtle* expression (assuming SA mode)
> cannot be written by using the proposed alternative syntax option.
> 
>       :bob :age 23 .
>       :alice :disbelieves <<:bob :age 23>> .
> 
> Perhaps this limitation is not an issue. The notion of edge properties in
> Property Graphs has the same limitation after all. What do you think?

I see {|...|} as convenience syntax.

The same happens with bnodes in the object position - if a bnode is 
object in two triples, you can't use [] notation, you have to use _:label.

On the syntax :

what about:

:bob :age 23 {| :origin
                    [ :source <http://bob.name/> ;
                      :retrieved "2020-09-02"^^xsd:date ]
              |} .

> Ignoring this potential issue, I thought a bit about my question from above:
> Can such an explicit distinction between SA mode and PG mode be built into the
> RDF* data model itself?

I need to work though the details in your message but could I ask what I 
do wonder what the value of having the distinction in the formal model, 
compared with, say, a data design pattern "PG mode is SA where each 
referenced <<>> triple is also in the data graph".

     Andy

Received on Wednesday, 2 September 2020 12:56:01 UTC