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Re: SPARQL paths and N3 paths: some quick thoughts.

From: Tim Berners-Lee <timbl@w3.org>
Date: Tue, 26 Jan 2010 12:39:21 +0100
Cc: public-cwm-talk@w3.org
Message-Id: <44E8FFBD-8C6A-430E-BA7C-C4EB56117661@w3.org>
To: Dan Connolly <connolly@w3.org>
Paths have been in N3 for a long time and much
discussed.

The characters used are "!" and "^".
A discussion of the options is in 
http://www.w3.org/DesignIssues/N3Alternatives#Syntax

It would be a really bad idea not to use the same punctuation in SPARQL.

Could you pass that on?

Tim

PS: Note also ^ is related to ^^ in that ^^ can be regarded 
as ^ if you want to reify datatypes -- to make an RDF
system which uses only strings.

On 2010-01 -22, at 22:10, Dan Connolly wrote:

> The SPARQL WG is looking at paths...
> http://www.w3.org/2009/sparql/docs/property-paths/Overview.xml
> 
> ... which is quite important for querying, e.g. lists:
> 
> select ?elt where { <alist> rdf:rest*/rdf:first ?elt }
> 
> Meanwhile, they're using / where n3 uses ., I think.
> 
> They use ^ both as N3 uses it and to do the is/of thing.
> 
> They also include regex syntax such as +,*, ? and {n,m}
> and ()s (but not for match groups).
> 
> It's pretty hard to argue against this in SPARQL; people
> have been asking for it from the very start of the SPARQL
> design.
> 
> Perhaps N3 should adapt in this direction?
> 
> The one place I'm inclined to push on is is/of; I'd
> hate to lose that from N3. Though... with the @keywords
> mechanism, maybe it's not so much of a conflict.
> 
> -- 
> Dan Connolly, W3C http://www.w3.org/People/Connolly/
> gpg D3C2 887B 0F92 6005 C541  0875 0F91 96DE 6E52 C29E
> 
> 
Received on Tuesday, 26 January 2010 11:36:32 GMT

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