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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

SELECT ?R
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
http://www.w3.org/2005/03/position2.html

[[
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 GMT

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