RE: data-r2 version of SPARQL tests

Hello Lee,

> http://www.w3.org/TR/rdf-concepts/ says that "A plain literal is a
string
> combined with an optional language tag."
> http://www.w3.org/TR/rdf-sparql-query/ , 11.4.7, says that "datatype ...
> returns the datatype IRI of typedLit; returns xsd:string if the the 
> parameter is a simple literal."

"simple literal" is defined in
http://www.w3.org/TR/rdf-sparql-query/#operandDataTypes :

"""
# simple literal denotes a plain literal with no language tag.
"""
"string"@en has a datatype, and so is not of an acceptable type for
datatype(). Therefore, datatype() returns an error which propagates to the
top of the FILTER and eliminates :x3 as a possible binding for ?x.



Thank you for explaination, now I understand why I don't have a bug.
Nevertheless I see a small problem: there's no way to destinguish "string"
and "string"^^xsd:string using only built-in functions.

Best Regards,
IvAn.