yet more on RDF XML literals (and NFC)

It appears to me that the processing for rdf:parsetype="Literal" can result
in illegal RDF graphs.

I believe that there is no requirement in processing RDF/XML that the
literal in production 7.2.17 of RDF/XML syntax must be in NFC or is
transformed to NFC by production 7.2.33. 

Similar issues affect the treatment of RDF XML literals in RDF Concepts.
The lexical space of RDF XML literals as defined in Section 5.1 does not
have any NFC requirement as far as I can see.   However, the lexical form
of a typed literal must be in NFC (Section 6.5).


I suggest that the limitation to NFC be dropped from RDF.  Not all
sources of XML will be in NFC, so RDF should not limit itself by requiring
non-NFC to be illegal.  It would be fine, and probably preferable, to
suggest that RDF processors produce warnings when they encounter *plain
literals* that are not in NFC.  Non-NFC in typed literals should not
produce warnings, as there may be types that usefully employ non-NFC.


Peter F. Patel-Schneider

Received on Tuesday, 26 August 2003 12:30:42 UTC