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Re: Scope

From: Sean B. Palmer <sean@mysterylights.com>
Date: Fri, 9 Nov 2001 16:45:53 -0000
Message-ID: <00ad01c1693e$14a17920$01ed93c3@localhost>
To: <www-rdf-rules@w3.org>
Cc: "Dan Brickley" <danbri@w3.org>
> First, I'd love to know what people have been building...

My turn...

Aaron Swartz and I have been working on the beginnings of an RDF API
written in Python, and we have written a query component (Gofyniad).
It's a simple query engine, viz. it takes triples out of the store
once it has matched them.

http://lists.w3.org/Archives/Public/www-archive/2001Oct/att-0040/01-go
fyniad
=>
http://cvs.plexdev.org/viewcvs/viewcvs.cgi/plex/plex/plexrdf/query.py
(1.1)

You'll need RDF API to run it (which is only about 2KB):-

http://cvs.plexdev.org/viewcvs/viewcvs.cgi/plex/plex/plexrdf/rdfapi.py
(1.4)

and we have an NTriples parser as well:-

http://cvs.plexdev.org/viewcvs/viewcvs.cgi/plex/plex/plexrdf/ntriples.
py (1.6)

Bijan Parsia gave a critique of the Query engine on RDF IG:-

http://ilrt.org/discovery/chatlogs/rdfig/2001-10-30.txt

To make it run:-

python query.py input.nt query.nt > out.nt

The query format is actually an extended NTriples, with ?x, ?y etc.
being universally quantified variables. Example query:-

input.nt:-
[[[
<#Sean> <#likes> <#TheSimpsons> .
<#Sean> <#likes> <#SemanticWeb> .
<#Sean> <#name> "Sean" .
]]]

query.nt:-
[[[
<#Sean> <#likes> ?x .
]]]

out.nt:-
[[[
@prefix : <tag:infomesh.net,2001-08-07:> .
@prefix rdfs: <http://www.w3.org/2001/01/rdf-schema#> .
:Result rdfs:subClassOf rdfs:Resource .

{
<rdfapi.Node instance at 007CA9BC> = #TheSimpsons .
} a :Result .

<#Sean> <#likes> <#TheSimpsons> .

{
<rdfapi.Node instance at 007CA82C> = #SemanticWeb .
} a :Result .

<#Sean> <#likes> <#SemanticWeb> .
]]]

as you can tell, we need to tweak the output function a little bit,
but the meat of the thing is done.

Cheers,

--
Kindest Regards,
Sean B. Palmer
@prefix : <http://webns.net/roughterms/> .
:Sean :hasHomepage <http://purl.org/net/sbp/> .
Received on Friday, 9 November 2001 11:46:24 UTC

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