- From: Dan Connolly <connolly@w3.org>
- Date: Sun, 08 Jan 2006 08:54:15 -0600
- To: Dave Beckett <dave@dajobe.org>
- Cc: public-rdf-dawg-comments@w3.org
On Sat, 2006-01-07 at 20:01 -0800, Dave Beckett wrote: > Dan Connolly wrote: > > On Sat, 2006-01-07 at 12:38 -0800, Dave Beckett wrote: > > > >>SPARQL refers to: > >> > >>[[ > >> [UNICODE] > >> The Unicode Standard, Version 4. ISBN 0-321-18578-1, as updated from > >> time to time by the publication of new versions. The latest version of > >> Unicode and additional information on versions of the standard and of > >> the Unicode Character Database is available at > >> http://www.unicode.org/unicode/standard/versions/. > >> > >>]] > >> > >>which cites a moving target. Please define SPARQL in terms of a > >>particular version of Unicode only, and no other. Otherwise if or when > >>this Unicode consortium makes some incompatible changes, all existing > >>implementations become invalid. > > > > > > How so? How is conformance to SPARQL sensitive to changes in Unicode? > > The SPARQL query syntax is defined on Unicode characters: > > [[ > A. SPARQL Grammar > > A SPARQL query string is a Unicode character string (c.f. section 6.1 > String concepts of [CHARMOD]) > ... > ]] > > although the grammar defines precise ranges of codepoints for particular > things such as names of variables (based on XML 1.1 I think). > > If the definition of a Unicode character string changes in some future > Unicode revision, such as for example by allowing additional codepoints, > then there will be additional codepoints allowed in a SPARQL query > string, following the sentence above. I believe that's by design, following... "C063 [S] A generic reference to the Unicode Standard MUST be made if it is desired that characters allocated after a specification is published are usable with that specification". http://www.w3.org/TR/2005/REC-charmod-20050215/#C063 I suppose I should check with the WG. > Any part of the grammar that uses an negated range such as with '[^...]' > will allow such codepoints. Examples include: > http://www.w3.org/TR/rdf-sparql-query/#rQ_IRI_REF > and all string literals. > > These codepoints may be refused by something implementing Unicode 4.0 > and no more. I suppose we need a test case that uses a codepoint that isn't currently allocated in Unicode 4.0. I still can't think of any reason why changes in Unicode specs would make any difference to SPARQL producers/consumers. It's not like they need to reference the Unicode tables to check the grammar or anything. > Dave -- Dan Connolly, W3C http://www.w3.org/People/Connolly/ D3C2 887B 0F92 6005 C541 0875 0F91 96DE 6E52 C29E
Received on Sunday, 8 January 2006 14:54:20 UTC