- From: Richard Newman <r.newman@reading.ac.uk>
- Date: Thu, 18 Aug 2005 13:26:54 -0700
- To: Tim Berners-Lee <timbl@w3.org>
- Cc: public-rdf-dawg-comments@w3.org, Yosi Scharf <syosi@mit.edu>
As I recall from discussions with Andy Seaborne while I was implementing twinql[1], the grammar in the SPARQL docs are directly generated from a JavaCC grammar file. The source, therefore, is machine-consumable -- at least, if you're using JavaCC! However, the output is not a particular friendly grammar to work with -- optional dots after productions, for example, tripped up my tool (so twinql makes them compulsory), and it took a bit of work to get it into a usable state (as I detailed in a previous email[2]). -R [1] <http://www.holygoat.co.uk/projects/twinql/> [2] <http://lists.w3.org/Archives/Public/public-rdf-dawg-comments/ 2005Aug/0055.html> On 18 Aug 2005, at 11:28, Tim Berners-Lee wrote: > > This is a followup from a discussion between Yosi Scharf, > implementer of SPARQL in cwm, currently on vacation, and Eric > P'dH, co-editor of the spec, several weeks ago. > > Yosi has built his implementation of SPARQL from a file which is > almost the one generated from the TR, but with a slight tweak to > make the file grammar able to be parsed by a predictive parser [1] > a simple form of LL(1) recursive descent parser. I understood that > the tweak was editorial in that the it didn't change the language, > just the way it was expressed as a context-free grammar. > > A situation in which code can be generated directly from the spec > is a very strong position to be in. I am not aware of any time > this has previously happened for a W3C language, but I may be > wrong. As it is demonstrably simple to make the step here I would > request it be done at last call stage before the call for > implementation at CR. > > [1] http://www.inf.ed.ac.uk/teaching/courses/cs2/LectureNotes/CS2Ah/ > LangProc/lp10.pdf > > Tim Berners-Lee > MIT/CSAIL/DIG > > >
Received on Thursday, 18 August 2005 20:27:06 UTC