Re: CWM Bug: bNodes Mistakenly Converted to URIs

That bug was caused by a missing line in query.py due to me being
confused at some point. The cwm CVS has it fixed (I ran into the same
thing about a month ago and just fixed it). I should add you testcase (I
have not done so yet).

Thanks for the feedback. It would be nice to feel confident about cwm
enough for me to make a release.


Yosi


Sean B. Palmer wrote:
> CWM is converting some bNodes to URIs when it shouldn't be, having
> used a filter which ironically is intended to convert formulae to
> bNodes.
>
> The motivation for the filter is that I've converted notation3.py to
> run as a standalone N3 to N-Triples converter. Now I need to get CWM
> to spit out some kind of reference output to test against, but the
> standalone notation3.py preserves triples with formulae in them,
> turning the formulae into bNodes.
>
> Since cwm --ntriples removes statements with formulae, that's no good
> as reference output. I've already filed a bug about cwm --flatten
> breaking; that's no good either. I was going to file a bug about cwm
> --reify, but its output is just too awful to get into at this stage,
> and so I wrote this filter instead:
>
> $ cat normalise.n3
> @prefix log: <http://www.w3.org/2000/10/swap/log#> .
>
> { ?s ?p ?o . ?s log:rawType log:Formula }
>  => { _:s ?p ?o } .
>
> { ?s ?p ?o . ?o log:rawType log:Formula }
>  => { ?s ?p _:o } .
>
> { ?s ?p ?o .
>   ?s log:rawType [ log:notEqualTo log:Formula ] .
>   ?o log:rawType [ log:notEqualTo log:Formula ] }
>  => { ?s ?p ?o } .
>
> Here's my test input:
>
> $ cat test.n3
> @prefix : <http://example.org/#> .
> @prefix foaf: <http://xmlns.com/foaf/0.1/> .
>
> [ :p :q, _:r, "r" ] .
> ("a" "b" "c") a :List .
> { ?p ?q ?r } a :Formula .
>
> # EOF
>
> And here's what happens:
>
> $ cwm test.n3 --filter=normalise.n3
> #Processed by Id: cwm.py,v 1.189 2006/08/02 16:59:14 syosi Exp
>
> #  Notation3 generation by
> #       notation3.py,v 1.191 2006/08/01 01:14:04 syosi Exp
>
>      @prefix : <http://example.org/#> .
>     @prefix test: <#> .
>
>       ( "a"
>         "b"
>         "c" )
>          a :List .
>
>     test:_g0     :p "r",
>                 :q,
>                 test:_g1 .
>       [      a :Formula ].
>
> #ENDS
>
> This is probably due to the fact that bNodes are stored internally as
> URIs at the most ancient and therefore the most ingrained layer of the
> API. Kinda hard to change. It would be nice, though, since this is
> also behind one of the things that makes the --reify output unusable.
>
> I'm using cwm-1.2.0a1 for this.
>
> Just in case the universals' local name space was conflicting with
> that of the bNodes, I tried it using this instead:
>
> { ?s ?p ?o . ?s log:rawType log:Formula }
>  => { [] ?p ?o } .
>
> { ?s ?p ?o . ?o log:rawType log:Formula }
>  => { ?s ?p [] } .
>
> But the same problem occurs.
>
> Thanks,
>
>

Received on Saturday, 13 October 2007 23:55:17 UTC