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Re: Turtle: Prefixes now can contain colons (":")?

From: David Booth <david@dbooth.org>
Date: Tue, 17 Jul 2012 09:43:07 -0400
To: Mathias Hasselmann <mathias@taschenorakel.de>
Cc: Gavin Carothers <gavin@carothers.name>, public-rdf-comments@w3.org
Message-ID: <1342532587.2728.12848.camel@dbooth-laptop>
On Tue, 2012-07-17 at 09:22 +0200, Mathias Hasselmann wrote:
> Am Montag, den 16.07.2012, 20:43 -0700 schrieb Gavin Carothers:
> > On Sat, Jul 14, 2012 at 1:40 PM, Mathias Hasselmann
> > <mathias@taschenorakel.de> wrote:
> > > Hello,
> > >
> > > When adopting code for the updated grammar I've noticed that that
> > > addition of colons to local names also injected colons to PN_PREFIX:
> > >
> > > http://dvcs.w3.org/hg/rdf/raw-file/default/rdf-turtle/index.html#grammar-production-PN_PREFIX
> > >
> > > [167s]  PN_PREFIX       ::=     PN_CHARS_BASE ((PN_CHARS | '.')* PN_CHARS)?
> > > [166s]  PN_CHARS        ::=     PN_CHARS_U | '-' | [0-9] | #00B7 | [#0300-#036F] | [#203F-#2040]
> > > [164s]  PN_CHARS_U      ::=     PN_CHARS_BASE | '_' | ':'
> > >                                                      ^^^^^
> > > Is that intentional?
> > 
> > Yes.
> > http://dvcs.w3.org/hg/rdf/raw-file/default/rdf-turtle/index.html#sec-changelog
> > 
> > The other major grammar addition is the support for PREFIX (without
> > the @) as seen in SPARQL.
> 
> Sure, it says: "Local part of prefix names can now include ":"".
> But the way I understand the sentence this is about the local part, not
> the prefix name itself. Am I missing something.
> 
> To illustrate the problem consider this prefixed name:
> 
> 	abc:def:ghi
> 
> What part is the prefix, what part is the local name? Especially if the
> document also contains this directives:
> 
> 	@prefix abc: "http://www.example.com/first"
> 	@prefix abc:def: "http://www.example.com/second"
> 
> Not saying this is impossible to implement, but I expect unnecessarily
> inefficient implementations, and also interoperability issues by
> allowing colons in the prefix name. What's actually the use case for
> permitting colons in the prefix name?

I completely agree with Mathias.  Colons should not be allowed in the
prefix.  That would be awful.



-- 
David Booth, Ph.D.
http://dbooth.org/

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Received on Tuesday, 17 July 2012 13:43:46 UTC

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