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Re: Turtle implementation report for RDF::Trine

From: Gregory Williams <GREG@EVILFUNHOUSE.COM>
Date: Thu, 4 Jul 2013 11:01:12 +0300
Cc: public-rdf-comments@w3.org
Message-Id: <CB25AB69-550C-4674-8295-6FAE12FCA9AB@EVILFUNHOUSE.COM>
To: Eric Prud'hommeaux <eric@w3.org>
On Jul 3, 2013, at 5:44 PM, Eric Prud'hommeaux <eric@w3.org> wrote:

> * Gregory Williams <GREG@EVILFUNHOUSE.COM> [2013-03-01 14:04-0500]
>> I've posted EARL results for my turtle parser at:
>> 
>> http://kasei.us/code/rdf-trine/rdf-trine-turtle-2013-03-01.ttl
>> 
>> I'd like to take this opportunity to provide feedback on the inclusion of SPARQL BASE and PREFIX syntax in the new Turtle grammar. I think this is a mistake, adding complexity for both users and implementors. I'm sympathetic to the desire to align syntax for triples between Turtle and SPARQL, but don't believe the alignment is necessary or recommended for the top-level language syntax (as the need for backwards compatibility with pre-REC Turtle means that alignment requires two different syntaxes for the same declarations).
>> 
>> If the WG thinks that this alignment is absolutely necessary, I object to the needless complexity of having two different rules regarding trailing DOTs depending on the lexical form used. For example, as written the grammar requires a trailing DOT after "@base", but forbids it after "BASE". I can't think of a reason why having these different rules would be a benefit to anyone. One solution to this might be to allow an optional DOT after either form, but as I said, I think the best thing would be to keep just a single syntax for these declarations.
> 
> Thank you for your feedback regarding the PREFIX and BASE directives
> in Turtle. The RDF Working Group has had extensive discussion and
> considering the long-term compatibility between Turtle and SPARQL, we
> have opted to include keep both forms with the current case
> sensitivity, with the goal of eventually favoring the form compatible
> with SPARQL. We appreciate that this is a frustrating transition but
> hope that it will lead to improved user experience in the long run.
>  <http://www.w3.org/2013/meeting/rdf-wg/2013-05-29#Turtle>
> 
> Please see <http://www.w3.org/mid/20130703143355.GA25039@w3.org> for
> more discussion.
> 
> If this resolution addresses your issues, please respond to this
> message with a subject line which starts with "[RESOLVED]". Thank you
> for your help in improving the Turtle specification.

Hi Eric,

I will accept this decision, but remain very unhappy about it as Turtle is an existing language in widespread use, and this feels like the WG making changes that add complexity with very little benefit. (I have similar complaints about the upcoming changes to N-Triples, which I'll address in that comment thread.)

However, this response does not address the second part of my comment, which was an objection to the needless complexity surrounding the grammar rules for the DOT following prefix/base statements. I didn't find much relevant about this issue in the mailing list archive (though very well could have missed it), and so am not sure if this was discussed within the WG before the decision was made. I'm not sure how believing that this is a "frustrating transition but hope that it will lead to improved user experience in the long run" aligns with requiring users in the near term to remember two different grammar rules. Why not have "@prefix" and "PREFIX" (similarly for "@base" and "BASE") be simply a syntactic variation with no difference in the grammar?

thanks,
.greg
Received on Thursday, 4 July 2013 08:01:38 UTC

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