W3C home > Mailing lists > Public > public-rdf-dawg@w3.org > October to December 2011

Re: Escape sequences (SPARQL and Turtle)

From: Steve Harris <steve.harris@garlik.com>
Date: Wed, 30 Nov 2011 11:15:06 +0000
Cc: public-rdf-dawg@w3.org
Message-Id: <24BD9DF1-4D20-4C95-831F-750F3B539F3F@garlik.com>
To: Andy Seaborne <andy.seaborne@epimorphics.com>
On 27 Nov 2011, at 21:18, Andy Seaborne wrote:

> RDF-WG is still discussing escape sequences.  One of the areas of debate is being able to put additional characters into prefixed names, motivated by (1) Facebook Open Graph Protocol, which naturally lead to ":" in the local part of prefix names and (2) convenience working with generated IRIs, e.g. R2RML.
> 
> OGP:
> <html xmlns:og="http://ogp.me/ns#">
> ....
>    <meta property="og:audio:title" content="Amazing Song" />
> ....
> 
> R2RML IRI template:
> http://data.example.com/employee={EMPNO}/department={DEPTNO}
> 
> 
> An original proposal to use unicode escapes (\u....) for this has resulted in some pushback.
> 
> A recent character-escape approach is also in this space [1].
> 
> PREFIX og:  <http://ogp.me/ns#>
> ...
>  og:audio\:title
> ...
> 
> == Progressing SPARQL 1.1
> 
> I don't think that "at risk" in CR works very well for "A or B" choices because whichever we choose, some implementation might have to change. If it's "A or not A" feature, then anything implementing A isn't made non-conformant, it's merely has an extension.
> 
> A way forward??
> 
> 1/ SPARQL's \u processing remains the same.  This means we are either adding something or not  We are not changing something - so closer to the charter.
> 
> 2/ Decide close to 2LC whether to put in an at-risk feature for \: etc. into 2LC.  Do this as close to 2LC as possible, seeing if RDF-WG has made progress.
> 
> If it gets through 2LC, we keep this feature in CR still "at-risk". Again, at CR, review whether RDF-WG is settled in this area.
> 
> 
> We can put some advice in the SPARQL/RDF-1.1 page if the feature is pulled.  As this advice page has no status, it won't get much prominence.
> 
> 	Andy
> 
> PS I have prototyped [1] in SPARQL and nothing broke nor were any tests affected.

OK, good to know. Does it do anything the the class of parser required to tackle SPARQL? I don't know how lexers etc. tackle escapes.

I imagine that adding a load of characters to what you're allowed to put right of the : in a qname in SPARQL will break things?

- Steve

> [1]
> http://lists.w3.org/Archives/Public/public-rdf-wg/2011Nov/0234.html
> 

-- 
Steve Harris, CTO, Garlik Limited
1-3 Halford Road, Richmond, TW10 6AW, UK
+44 20 8439 8203  http://www.garlik.com/
Registered in England and Wales 535 7233 VAT # 849 0517 11
Registered office: Thames House, Portsmouth Road, Esher, Surrey, KT10 9AD
Received on Wednesday, 30 November 2011 11:15:53 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 16:15:47 GMT