W3C home > Mailing lists > Public > public-rdf-wg@w3.org > August 2011

Re: RDF-ISSUE-74: Prefixed names and slashes [RDF Turtle]

From: Richard Cyganiak <richard@cyganiak.de>
Date: Mon, 15 Aug 2011 11:24:57 +0100
Cc: RDF Working Group WG <public-rdf-wg@w3.org>
Message-Id: <29311E5C-903E-4307-B31D-23EBAE4D5665@cyganiak.de>
To: Gavin Carothers <gavin@topquadrant.com>
On 15 Aug 2011, at 05:36, Gavin Carothers wrote:
> On Sat, Aug 13, 2011 at 12:08 PM, Richard Cyganiak <richard@cyganiak.de> wrote:
>> Gavin,
>> 
>> On 12 Aug 2011, at 19:14, RDF Working Group Issue Tracker wrote:
>>> New Turtle:
>>> 
>>> Allowed:
>>> @prefix bob: http://example.org/bob/ .
>>> bob:goldfish\u002F1
>> 
>> Is that allowed? Section 4.3 [1] says that all the backslash escapes are only allowed inside strings and IRI_REF. I don't see anything that allows them inside prefixed names.
> 
> Then section 4.3 doesn't agree with the grammar:
> 
> http://www.w3.org/TR/turtle/#term-turtle2-PN_CHARS_BASE
> 
> One of them gets to give.

\u and \U escapes shouldn't be allowed in prefixed names. This has been discussed on the list before. Prefixed names are syntactic sugar to make reading and writing of IRIs easier. Escapes like \u0021 are neither easy to read nor easy to write, so they defeat the purpose of prefixed names.

> Specific example:
> 
> @prefix turtleDocLoc: <http://www.w3.org/TR/2011/WD-turtle-20110809/>
> 
> turtleDocLoc:examples/example1.ttl
> 
> It's very surprising not to be able to write that.

If you know about XML prefixes, then it isn't surprising.

> You can get around
> it by using @base a lot more, or by defining a LOT of prefixes. :\
> Neither solution is very readable.

If you have a lot of IRIs that don't share a common base, then you'll end up having a lot of <full_absolute_IRIs> in your file. What's so strange about that? It's no different from HTML.

I think there is consensus in the group that we should not add extensions to Turtle at this point. We should just standardize it as it is already implemented (modulo SPARQL alignment).

Personally I am very strongly opposed to extending Turtle in ways that are incompatible with SPARQL.

Best,
Richard
Received on Monday, 15 August 2011 10:25:33 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 16:25:44 GMT