- From: Hugh Glaser <hugh@glasers.org>
- Date: Mon, 2 Dec 2013 12:35:36 +0000
- To: public-lod community <public-lod@w3.org>
Hmm, My head is spinning a bit now - I’m trying to understand something simple - "1"^^xsd:boolean. So my reading says that is a valid lexical form (in the lexical space) for the value ’true’ (in the value space). (http://www.w3.org/TR/rdf11-concepts/#dfn-lexical-space ) I think that ‘value space’ is where the other documents talk about 'RDF term’, but I’m not sure. And I also I read: "Literal term equality: Two literals are term-equal (the same RDF literal) if and only if the two lexical forms, the two datatype IRIs, and the two language tags (if any) compare equal, character by character.” (http://www.w3.org/TR/rdf11-concepts/#section-Graph-Literal ) So the language processor will (must) take my lexical form "1"^^xsd:boolean and make it an RDF term “true" And then if I ask the store (sorry, I am rather engineering in this) if 2 terms are equal, it will always be comparing two similar terms (from the literal space), (probably, but see below): “true"^^xsd:boolean And I can expect a sensible querying engine to consider "1"^^xsd:boolean as a shorthand for “true" It could be confusing, which it was for a bit for me, because the equality constraint says "the two lexical forms”, but in this case there is more than one lexical from for the value form. So I think it means that a processor must always choose the same lexical form for any given value form. I am guessing that processors could consistently choose "1"^^xsd:boolean as the value form for “true" but that would be pretty perverse. A little further confusion for me arises as to whether the datatype IRI is part of the value space. I have taken off any ^^xsd:boolean from my rendering of the “true” in the value space because the documentation seems to leave it out. (The table says: '<“true”, xsd:boolean>’ and ‘true’ are the literal and value.) So I am left assuming that the datatype IRI is somewhere in the RDF term world, although we know it isn’t in the graph. Not something I need to worry about as a consumer, as it is all an internal issue, I think, but I thought I would mention it. Best Hugh -- Hugh Glaser 20 Portchester Rise Eastleigh SO50 4QS Mobile: +44 75 9533 4155, Home: +44 23 8061 5652
Received on Monday, 2 December 2013 12:36:05 UTC