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Re: evaluating SPARQL w.r.t an RDF query language survey

From: <jos.deroo@agfa.com>
Date: Wed, 6 Apr 2005 22:13:39 +0200
To: connolly@w3.org
Cc: RDF Data Access Working Group <public-rdf-dawg@w3.org>
Message-ID: <OF2BE3B9F7.B1188C25-ONC1256FDB.006C9A4B-C1256FDB.006F1CBA@agfa.com>

picking out just one case.. (have tested 11 cases a while back)

> 10 Namespace
> Return all resources whose namespace starts with
> "http://aifb.uni-karlsruhe.de/".
> seems to have a typo in the question...
> missing www.
> select ?R where
>  { ?R ?x ?y.
>    FILTER regex(str(?R), "http://www.aifb.uni-karlsruhe.de/")
> }

why not simply

WHERE {?R a rdfs:Class;
          log:uri ?S.
       ?S str:matches "http://www\.aifb\.uni-karlsruhe\.de/.*"}

or some such (I don't have enough regex experience)

I'm even more convinced after reading

Built-in Functions and operators: Use RDF Properties

... All this speaks against built-in functions being
brought out as special syntax, and supports the use of
RDF properties for them.

The point is also about that separate FILTER, I'm not
convinced at all and basically a query is already a
filter rule

{where-triple-pattern} => {construct-or-select-triple-pattern}

I just don't see the benefit of having FILTER in filter..

Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/
Received on Wednesday, 6 April 2005 20:13:49 UTC

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