- From: Eric Prud'hommeaux <eric@w3.org>
- Date: Tue, 12 Jun 2007 10:40:05 -0400
- To: Lee Feigenbaum <feigenbl@us.ibm.com>
- Cc: public-rdf-dawg@w3.org
- Message-ID: <20070612144005.GA6160@w3.org>
* Lee Feigenbaum <feigenbl@us.ibm.com> [2007-06-12 03:06-0400] > ACTION: ericP to walk through one full example of representing an > algebraic expression using the XPath-based facet stuff chimezie and i went over this at the end of the telecon. i just noticed that i had said i'd do this for everyone. i think it's slightly more useful for the audience if i don't couch it terms of the folded algebraic expressions but instead a simple "does SPARQL do X?" question. Suppose you want to find the tests for { A OPT B OPT C }. Go to http://www.w3.org/2005/01/yacker/uploads/SPARQL and dream up a query: SELECT * WHERE { ?s1 ?p1 ?o1 OPTIONAL { ?s1 ?p1 ?o1 } OPTIONAL { ?s1 ?p1 ?o1 } } stick it in the "Input some text to test" box and submit Submit SUBMIT!!! http://w3.org/brief/NDY= A trimmed view of the parse tree (as XML) looks like: <Query> <SelectQuery> <WhereClause> <GroupGraphPattern> <TriplesBlock> </TriplesBlock> <GraphPatternNotTriples> <OptionalGraphPattern> <GroupGraphPattern> <TriplesBlock> </TriplesBlock> </GroupGraphPattern> </OptionalGraphPattern> </GraphPatternNotTriples> <GraphPatternNotTriples> <OptionalGraphPattern> <GroupGraphPattern> <TriplesBlock> </TriplesBlock> </GroupGraphPattern> </OptionalGraphPattern> </GraphPatternNotTriples> </GroupGraphPattern> </WhereClause> </SelectQuery> </Query> http://www.w3.org/2007/06/12-A-OPT-B-OPT-C.xml The pattern /Query/SelectQuery/WhereClause/GroupGraphPattern [TriplesBlock] [GraphPatternNotTriples[1]/OptionalGraphPattern] [GraphPatternNotTriples[2]/OptionalGraphPattern] will detect that pattern. An XSLT like http://www.w3.org/2007/06/12-A-OPT-B-OPT-C.xsl http://www.w3.org/2005/08/online_xslt/xslt?xslfile=++http%3A%2F%2Fwww.w3.org%2F2007%2F06%2F12-A-OPT-B-OPT-C.xsl&xmlfile=++http%3A%2F%2Fwww.w3.org%2F2007%2F06%2F12-A-OPT-B-OPT-C.xml&content-type=&submit=transform (or, briefly, http://w3.org/brief/NDc= ) shows the match. -- -eric office: +1.617.258.5741 NE43-344, MIT, Cambridge, MA 02144 USA mobile: +1.617.599.3509 (eric@w3.org) Feel free to forward this message to any list for any purpose other than email address distribution.
Received on Tuesday, 12 June 2007 14:40:08 UTC