Re: Is there a way to self-reference a named graph? [was: Re: Is <> a legal way to self-reference a named graph in a dataset in TriG?]

On 18/09/2022 10:03, Thomas Lörtsch wrote:
> [Changing the subject line as the subject changed]
> 
>> Am 18.09.2022 um 09:15 schrieb Lorenz Buehmann <buehmann@informatik.uni-leipzig.de>:
>>
>> Hi,
>>
>>
>>> Thank you very much, that answered one part of my question exhaustively! But it doesn’t solve my problem: how would I refer to a named graph in a dataset from inside that named graph without knowing its name? It now seems to me that that’s simply not possible.
>>
>> When and why would you not know the name of the named graph? Who is producing the RDF dataset? What means "refer to a named graph inside the named graph"?
> 
> You could aks all those questions just as well about the '<>' reference to a document or a dataset, and you’ll find uses of the '<>' self reference often enough "in the wild" to give you an idea of possible use cases.

This is a web concept, not an RDF concept.

<> is a relative URI.

It is resolved - RFC 3986, Section 5.

The base URI can be provided in several ways. Often it is "(5.1.3) URI 
used to retrieve the entity".


Fragments can be used:

GRAPH <#xyz> {
   <#xyz> :property ...
}


The only RDF thing is that there is syntax to set the base URI during 
parsing. And it can change within the document.

[[
BASE <http://example/someBase>
PREFIX : <http://example/>

<> :p "ABC" .

BASE <http://example/someBase2>

<> :p "ABC" .
]]

is two triples.

Uncommon, but this can be useful when collecting and concatentating 
Turtle documents.

     Andy

> 
>> What do you want to achieve?
> 
> My use case is rather special - declaring the semantics of a graph from within the graph - and I don’t want discussions if that makes sense to get into the way of discussing the issue at hand.
> 
> Best,
> Thomas
> 
> 
>>
>> Cheers,
>>
>> Lorenz
>>
>>
>>>
>>> Thomas
>>>
>>>
>>>> best
>>>>
>>>>> Best,
>>>>> Thomas
>>>>>
>>>>>
>>>>>
>>>>> [0] The example glosses over the fact that the rest of this document is not valid RDF. A similar example can be found in the heading of <http://infomesh.net/2002/notation3/>
>>>> <OpenPGP_0x9D1EDAEEEF98D438.asc>
>>>
>>>
>>
> 
>

Received on Sunday, 18 September 2022 09:48:01 UTC