test for DATATYPE on plain literals, please

"It returns <xsd:string> if the argument is an untyped literal."
 -- http://www.w3.org/2001/sw/DataAccess/rq23/#func-datatype


SPARQLer doesn't seem to agree; I tried this query:

SELECT ?book ?title WHERE { ?book dc:title ?title FILTER
( DATATYPE(?title)) }

http://sparql.org/books?query=PREFIX+books%3A+++%3Chttp%3A%2F%
2Fexample.org%2Fbook%2F%3E%0D%0APREFIX+dc%3A++++++%3Chttp%3A%2F%
2Fpurl.org%2Fdc%2Felements%2F1.1%2F%3E%0D%0ASELECT+%3Fbook+%3Ftitle
+WHERE+%7B+%3Fbook+dc%3Atitle+%3Ftitle+FILTER+%28+DATATYPE%28%3Ftitle%
29%29+%7D%0D%0A&stylesheet=xml-to-html.xsl

and got no results.

I suspect SPARQLer is not quite caught up there. To make sure
developers learn about this detail, let's make sure there's a test,
please.

Steve, would you please add a test or get somebody to do it?
Or if one is already there, point me to it?

I looked, and the closest I see is something with doubles.
http://www.w3.org/2001/sw/DataAccess/tests/#datatype-1

-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
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