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Re: Review of Query document

From: Nico Michaelis <nico.michaelis@sohard.de>
Date: Tue, 21 Sep 2010 15:56:56 +0200
Message-ID: <4C98B9A8.8000505@sohard.de>
To: Andy Seaborne <andy.seaborne@epimorphics.com>, public-rdf-dawg@w3.org
> That's easy to address - the grammar wasn't up to date.
>
> The master copy is
>
> http://www.w3.org/2009/sparql/docs/sparql-grammar-11.html

Two little thoughts regarding the grammer:

1)

ExistsFunc  	  ::=    	'EXISTS' GroupGraphPattern
NotExistsFunc 	  ::=   	'NOT EXISTS' GroupGraphPattern

Doesn't the rule

ExistsFunc  	  ::=    	'NOT'? 'EXISTS' GroupGraphPattern

suffice? Anyways, the NotExistsFunc definition forces the lexer to look 
exactly for ' EXISTS' after any 'NOT', which will make the lexer more 
complex, since you can't assume that any keyword ends with a whitespace 
- both rules even force a specific whitespace. The same holds for the 
'NOT IN' in the RelationalExpression rule.

2)

WhereClause  	  ::=    	'WHERE'? GroupGraphPattern

Never noticed that the 'WHERE' is optional. I didn't find a place where 
that would lead to ambiguities, but is it intended?

Best

Nico
Received on Tuesday, 21 September 2010 13:57:29 GMT

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