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Re: ACTION 2001-10-12#5: frankm respond to gk text

From: Pat Hayes <phayes@ai.uwf.edu>
Date: Sun, 14 Oct 2001 17:42:05 -0500
Message-Id: <p05101023b7efc47c511b@[205.160.76.193]>
To: Frank Manola <fmanola@mitre.org>
Cc: w3c-rdfcore-wg@w3.org
>Pat Hayes wrote:
>
>>......
>>
>>>A clearer explanation of how our resolution affected the questions 
>>>that were originally raised would explicitly address the existence 
>>>of the locally-generated names we talk about (at least in 
>>>Ntriples), and would go something like this:
>>>
>>>"This resolves specific questions in the original issue raised thus:
>>>
>>>[1.] Should anonymous resources have URI's?
>>>  -- No (point 1 above).  However, they are assigned local names, 
>>>of the form '_:name'.  These names are not URIs, and their scope 
>>>is the N-triples document in which they appear.
>>
>>
>>Er... be careful. Those are names for NODES, not for the resources 
>>that the nodes refer to in the RDF semantics. We really should be 
>>careful not to say anything that could be read as saying that these 
>>'_:name' thingies are names of anything in the RDF semantic domain. 
>>They are entirely to do with the Ntriples-to-graph mapping, which 
>>is a mapping between two different syntaxes. By the time one gets 
>>to talking about resources (the ones that the RDF graph is talking 
>>about) those bNode names are completely gone. An unlabeled node 
>>really has NO label. (Which is why it makes perfect sense that they 
>>should not be URIs, by the way.)
>
>
>Point taken.  How about this?
>
>[1.] Should anonymous resources have URI's?
>  -- No (point 1 above).  However, in order to refer to bNodes in 
>N-triples, the bNodes  are assigned local names, of the form 
>'_:name' (point 2 above).  These names are not URIs, and their scope 
>is the N-triples document in which they appear.
>
>It also might be worthwhile, in order to nail this point down, to 
>change point 2 from starting "To reflect un-named descriptions in 
>N-triples" to "To refer to bNodes in N-triples".

I'm happy with both of these.

>
>
>>
>>>[2.] If so, should they be clearly distinguishable as parser 
>>>generated URI's?
>>>  -- Stricly speaking, the parser is not required to generate URIs. 
>>>The parser *is* required to generate local names (that are not 
>>>URIs) for anonymous resources. These names *are* distinguishable 
>>>from URIs.
>>
>>
>>What exactly is 'the parser' here? (Parser of what?) If the parser 
>>is parsing an Ntriples document, then the bNode ids are in the 
>>document already and nothing needs to be generated. If the parser 
>>is dealing directly with the graph syntax, then there is no need 
>>for the bNode labels at all, and nothing needs to be generated. If 
>>the parser is reading RDF/XML and constructing a graph, no new 
>>names need to be generated. The only case that requires generating 
>>any new names is when something is reading either a graph or 
>>RDF/XML, and *generating* an N-triples document. In that case, and 
>>that case alone, it needs to generate some bNode names (since the 
>>Ntriples syntax requires them and they aren't present in any other 
>>version of RDF.)  But that is an issue with Ntriples, not 
>>(centrally) with RDF itself, and I think we should keep those 
>>issues separate. Our remit, after all, is to clarify RDF; 
>>N-triples is only a handy notation we have invented for describing 
>>RDF graphs, right? The graph is central.
>>
>
>
>Graham's point 1 starts off talking about "Resources that are 
>described but not
>named in an XML serialization", so I had assumed that the parser in 
>question was
>an XML parser.  Also, as you say, any "parser" reading a graph and generating
>N-triples would also need to generate bNode names.  I think one of the things
>we need to keep in mind in constructing this (and some other) text 
>is that people who had issues with the M&S don't necessarily have 
>this "graph is
>central" point of view that we've adopted;  they may very well think
>(encouraged by various statements in previous writings about RDF) 
>that the XML syntax is what's central, and the graph is just an 
>expository mechanism.   We're going to have to make sure we get the 
>"graph is central" idea across.
>

Right, but that is a more global effort; and in the meantime, lets 
just make sure we always say 'XML parser' or whatever. I honestly was 
not sure what you meant here, hence the screed.

Pat
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Received on Sunday, 14 October 2001 18:42:26 EDT

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