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Re: N-triples white space question

From: Eric Prud'hommeaux <eric@w3.org>
Date: Fri, 18 May 2012 08:12:50 -0400
To: Richard Cyganiak <richard@cyganiak.de>
Cc: Andy Seaborne <andy.seaborne@epimorphics.com>, RDF-WG <public-rdf-wg@w3.org>
Message-ID: <20120518121250.GB5291@w3.org>
* Richard Cyganiak <richard@cyganiak.de> [2012-05-18 12:35+0100]
> 
> On 18 May 2012, at 11:34, Eric Prud'hommeaux wrote:
> > Does the existing body of N-Triples permit a grammar with no default whitespace rules?
> > 
> >  triples: triple (LF triple)* LF?
> >  triple: subject HWS predicate HWS object '.'
> > 
> > I.e, do all the N-Triples out there look like "<s> <p> <o>."?
> 
> This is what N-Triples as currently defined requires. Isn't that sufficient?
> 
> ntripleDoc	::=	line*
> line		::=	ws* ( comment | triple )? eoln	
> triple		::=	subject ws+ predicate ws+ object ws* '.' ws*
> ws		::=	space | tab	
> eoln		::=	cr | lf | cr lf	

I was just interested to see how much your SHOULD:
[[
* Richard Cyganiak <richard@cyganiak.de> [2012-05-18 11:06+0100]
> I would even go one step further and add some SHOULD-level guidance on where to put what whitespace. Perhaps something like: exactly one space between s and p; exactly one space between p and o; no WS before or after the period; no WS at
the start of a line; CR+LF as EOL.
]]
could be turned into a MUST.


> Richard
> 
> 
> 
> > I note that Oracle has been vigilent about preserving backwards-compatibility. Souri, do you have a sense of what Oracle has been using?
> > 
> >> I also note that RDF 2004 N-Triples allows comments (only at the start of a line). This makes sense for the use as a test case format, but not much sense for the use as a dump format.
> >> 
> >> Best,
> >> Richard
> >> 
> >> 
> >> [1] http://www.w3.org/TR/rdf-testcases/#ntriples
> >> 
> >> 
> >> 
> >> On 18 May 2012, at 10:04, Andy Seaborne wrote:
> >> 
> >>> Gavin, Eric,
> >>> 
> >>> rdf-turtle says:
> >>> 
> >>> [1] ntriplesDoc	::= (triple)? (EOL triple)* (EOL)?
> >>> [2] triple	::= subject predicate object '.'
> >>> [8] EOL		::= ([#xD#xA])+
> >>> 
> >>> What are the white space rules?
> >>> 
> >>> Does it inherit white space processing from the rest of Turtle? Comments seem to come from Turtle.
> >>> 
> >>> If it does not inherit white space rules,
> >>>   what about horizontal white space inside triples?
> >>> 
> >>> If it does inherit white space rules,
> >>>  that includes newlines within triples between S/P or P/O.
> >>> 
> >>> The simplest solution is to add text in section 12.3 to say that horizontal white space outside tokens is discarded (which is different to Turtle).
> >>> 
> >>> 	Andy
> >>> 
> >> 
> >> 
> > 
> > -- 
> > -ericP
> > 
> 

-- 
-ericP
Received on Friday, 18 May 2012 12:13:25 GMT

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