- From: Peter Frederick Patel-Schneider <pfps@research.bell-labs.com>
- Date: Mon, 21 Nov 2011 14:43:19 -0500
- To: <richard@cyganiak.de>
- CC: <public-rdf-wg@w3.org>
From: Richard Cyganiak <richard@cyganiak.de> Subject: XML literals poll Date: Mon, 21 Nov 2011 13:32:01 -0600 > Below are six questions on XML literals. Please help the WG get a > feeling for the general opinion within the group by answering the > questions. Answers in the usual +1/±0/-1 style are appropriate. > Thanks, > Richard > > > > Q1. Should the specs define a way to compare XML literals based on value? > > In other words, in the same way that integers 7 and 007 have the same > value, should <foo/> and <foo></foo> be defined as having the same > value? This is inherent in being a datatype, so +1 > Q2. Should the specs say that RDF implementations MUST support value-based comparison? > > In other words, assuming the specs define a value space that answers > Q1 in the affirmative, is it required that all RDF toolkits implement > some sort of canonicalization somewhere in the process? What is an RDF implementation? > Q3. Should the *lexical* space be in canonical form? > > In other words, should > <> ex:value "<foo/>"^^rdf:XMLLiteral. > <> ex:value "<foo></foo>"^^rdf:XMLLiteral. > > result in a graph with one triple (canonicalize) or two (don't > canonicalize)? Note that if you answer “two”, then it is unavoidable > that round-tripping an XML literal, or storing the same XML literal in > two different formats (say, RDF/XML and Turtle) and reading it again, > will sometimes result in a different triple (with the same value > though). -1 > Q4. Should *invalid XML* be allowed in the lexical space? > > In other words, should "</bar !!!>"^^rdf:XMLLiteral be ill-typed (just > like "AAA"^^xsd:integer) or well-typed (just like "</bar > !!!>"^^xsd:string)? +1 > Q5. Should the specs say that RDF/XML parsers MUST canonicalize when > handling parseType="literal"? > > RDF/XML parsers are often implemented on top of an XML parser, and > hence they don't have access to a low-level representation of the XML > literal, e.g., did it use single or double quotes in the attributes, > what order where the attributes in, or how many spaces were between > them? If they don't canonicalize, then two different RDF/XML parsers > would be pretty much guaranteed to parse the same RDF/XML file into > different triples (or even different runs of the same parser over the > same file could yield different triples). =0 > Q6. Should it be required that producers of XML literals in concrete > syntaxes (Turtle, N-Triples, other parseTypes in RDF/XML) canonicalize > the literals themselves? > > If the lexical space is canonicalized (see Q3), then it means that > canonicalization either has to be done by parsers (see Q5), or by > content producers. -1
Received on Monday, 21 November 2011 19:45:11 UTC