SSFS & Direct Semantics clarification: Invalid or inconsistent literals

I am trying to resolve ambiguity with respect to literals for which
the lexical value is not permitted by the datatype.  E.g.,

"string"^^xsd:decimal
"1.5"^^xsd:integer

The question is whether such literals are (1) prohibited by the
structural specification or (2) inconsistent according to the Direct
Semantics.

I find (2) to be more intuitive and I think it more closely aligns
with the RDF Based Semantics (to which I defer to Michael Schneider).
But...

I believe that the intent of the current specifications is (1).  SSFS,
section 5.7 says "The lexical form MUST conform to restrictions of the
datatype, and it is mapped to a data value as specified by the
datatype." And in the Direct Semantics document, the literal
interpretation function is undefined for such literals.

If (1) is correct, then I suggest rewording the quoted sentence to
remove confusion due to the phrase "restrictions of the datatype".
E.g., I believe the following is less ambiguous and reuses the wording
from the definition of datatype map.

"The lexical form MUST be an element of the lexical space of the
datatype, and it is mapped to a data value as specified by the
datatype."


If (2) is correct, then the quoted sentence should be removed and the
Direct Semantics should be extended to handle this case (which I
believe would be a relatively minor change).


-- 
Mike Smith

Clark & Parsia

Received on Friday, 12 June 2009 16:34:03 UTC