- From: Alexandre Passant <alexandre.passant@deri.org>
- Date: Wed, 31 Mar 2010 11:55:59 +0100
- To: Andy Seaborne <andy.seaborne@talis.com>
- Cc: SPARQL Working Group <public-rdf-dawg@w3.org>
On 31 Mar 2010, at 11:35, Andy Seaborne wrote: > > > On 31/03/2010 11:11 AM, Alexandre Passant wrote: >> >> On 31 Mar 2010, at 09:13, Andy Seaborne wrote: >> >>> Should the syntax of MINUS be like UNION with {} on the left-hand side >>> >>> { { ?s a foaf:Person >>> ?s foaf:name ?name >>> } >>> MINUS >>> { ?s foaf:knows ?other } >>> } >>> >>> or without: >>> >>> { ?s a foaf:Person . >>> ?s foaf:name ?name . >>> MINUS { ?s foaf:name ?name } >>> } >> >> My preference for the second one, saves a few editing process when adding / removing a MINUS clause from an existing query. > > For the record, we could change UNION to allow {}-less LHS > > A chain of UNIONs would be > > pattern UNION { pattern } UNION { pattern } Would be nice indeed. Alex. > > This has no effect on SPARQL 1.0 style queries. > > { pattern } UNION { pattern } UNION { pattern } > > is still legal and the same semantics. It's just a tweak to the grammar - the same AST and same algebra would result. > > (Ditto any future INTERSECTION which would presumably be the same as doing a join and projecting to common variables in SPARQL). > > Andy > -- Dr. Alexandre Passant Digital Enterprise Research Institute National University of Ireland, Galway :me owl:sameAs <http://apassant.net/alex> .
Received on Wednesday, 31 March 2010 11:00:16 UTC