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ISSUE-45 (termtype-iris): IRIs instead of literals for rr:termType choices [R2RML]

From: RDB2RDF Working Group Issue Tracker <sysbot+tracker@w3.org>
Date: Mon, 20 Jun 2011 11:36:14 +0000
To: public-rdb2rdf-wg@w3.org
Message-Id: <E1QYcm6-0004UA-RM@barney.w3.org>

ISSUE-45 (termtype-iris): IRIs instead of literals for rr:termType choices [R2RML]

http://www.w3.org/2001/sw/rdb2rdf/track/issues/45

Raised by: Richard Cyganiak
On product: R2RML

Raised by Drew Perttula:
http://lists.w3.org/Archives/Public/public-rdb2rdf-comments/2011Jun/0000.html


http://www.w3.org/TR/2011/WD-r2rml-20110324/#ObjectMapClass_termType_Property
currently says:
rr:termtype rdfs:range {"IRI", "BlankNode", "Literal"} .

I was expecting those choices to be URIs themselves, not strings. http://www.w3.org/TR/rdf-schema/#ch_literal is already a well-known id for "Literal" that I think has the right meaning for this context. I'm less sure what existing URIs to use for the other two, but it seems like they ought to exist or be added to a more core spec. rdfs:Resource, maybe?

Some reasons it would be better to use URIs than strings:
1. The values will be able to link to their own metadata, notably documentation
2. It's a good habit to promote. People will be copying r2rml's practices in their own RDF data.
3. If you want, you can make up superclasses for the allowed values (something like "Term" in this case and "Reference" in the SubjectMapClass case) and potentially simplify the rr:termtype definitions. UIs for r2rml are probably making some equivalent of those superclasses (aka enums) anyway.
Received on Monday, 20 June 2011 11:36:16 GMT

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