StreamRDF is an interface called by parsers (and other things) based on what it sees.

If in, say Turtle, teh pasrer sees a "BASE" then base(...) is called.

StreamRDF (it is an interface) does not do anything - its a stream of incoming RDF for the implementation to deal with.

StreamRDFLib.writer writes N-quads.  No way to say "BASE".

Triples sent to triple() should be already resolved - a parser responsibility.

    Andy

On 14/08/2019 09:28, Claude Warren wrote:
The StreamRDF just passed the base() argument on to the sink so that the
sink would have the base in order to set create the FQ URI from local
URIs.

StreamRDFLib simply ignores the base() call.

Did you mean StreamRDFBase?

StreamRDFLib is a colelction of fucntiosn and isn't itself does not have the StreamRDF interface.

 I assume this is because it
is intended to process fully qualified RDF.

I think the assumption is that if you are streaming into the graph you
would need the base() to resolve any inbound local URIs while if you are
streaming out from the graph the URIs are already fully resolved.

I didn't write this code so I am not certain but if that is the case
perhaps we should note it in the javadocs.

I do note that StreamRDF says it is for output, in which case I am not
certain why the base() is needed at all.

Claude



On Tue, Aug 13, 2019 at 11:46 PM Martynas Jusevičius <marty...@atomgraph.com>
wrote:

Hi,

I'm trying to understand what the purpose/usage of StreamRDF.base() is.

Isn't it supposed to set the base URI that relative URIs in the stream
resolve against?

I've made a simple test:

     StreamRDF rdfStream = StreamRDFLib.writer(new BufferedWriter(new
OutputStreamWriter(System.out)));
     rdfStream.start();
     rdfStream.base("http://localhost/";);
     rdfStream.triple(new Triple(NodeFactory.createBlankNode(),
NodeFactory.createURI("relative"), NodeFactory.createBlankNode()));
     rdfStream.finish();

The output I get:

_:Bf410fc50X2De0baX2D464eX2D996eX2Dbb3207090baa <relative>
_:B4b65b796X2D3561X2D4bf3X2Dbf31X2D1154aac0c816 .

Why is the property URI <relative> and not <http://localhost/relative>?
Doesn't that make the output invalid N-Triples? Or am I writing it wrong?

Martynas
atomgraph.com



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