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Re: Escaped characters in RDF-1.1 N-Triples literals for Canonical documents

From: Andy Seaborne <andy@apache.org>
Date: Fri, 06 Dec 2013 12:11:35 +0000
Message-ID: <52A1BEF7.5090106@apache.org>
To: Peter Ansell <ansell.peter@gmail.com>, "Booth, Jonathan" <J.Booth@nature.com>
CC: "public-rdf-comments@w3.org" <public-rdf-comments@w3.org>
Peter,
David,

Thank you for your comments regarding the rules for using ECHAR in 
Canonical N-Triples documents.

The wording on use of ECHARS has been clarified:

"""
* Characters MUST NOT be represented by UCHAR.

* Within STRING_LITERAL_QUOTE, only characters not allowed directly in 
STRING_LITERAL_QUOTE (U+0022, U+005C, U+000A, U+000D) should use ECHAR. 
For all other characters, ECHAR MUST NOT be used.
"""

https://dvcs.w3.org/hg/rdf/raw-file/default/rdf-turtle/n-triples.html#canonical-ntriples

Please could both of you reply with "[RESOLVED]" in the subject line to 
acknowledge handling of this comment.

	Andy



On 28/11/13 22:28, Peter Ansell wrote:
> Hi Andy,
>
> Thank for working through the ECHAR issue. Having ECHAR consistent
> across the variations is definitely useful.
>
> Could you also clarify the main issue that I am raising here about the
> Canonical form for N-Triples and which characters are expected to be
> escaped? It isn't completely clear whether "\" escapes should be used
> for all 8 represented characters in ECHAR or just the 4 that are
> disallowed in STRING_LITERAL_QUOTE [1].
>
> If only the 4 that are disallowed can be used, then one would need to
> use the raw character, as the last rule in Canonical N-Triples says
> that the \u form isn't allowed to be used either, but it isn't
> completely clear whether that is the intention.
>
> If the goal of Canonical N-Triples is to be fairly close to the RDF
> Test Cases format (with the exception of UTF-8 being preferred against
> \u|\U) then having at least the 5 escaped ASCII characters that it
> specifies [2] (and hopefully all 8 from RDF-1.1 N-Triples ECHAR) may
> make sense.
>
> Thanks,
>
> Peter
>
> [1] http://www.w3.org/TR/2013/CR-n-triples-20131105/#grammar-production-STRING_LITERAL_QUOTE
> [2] http://www.w3.org/TR/rdf-testcases/#ntrip_strings

On 03/12/13 22:52, David Booth wrote:
 > 1. http://www.w3.org/TR/n-triples/#dfn-canonical-n-triple-document
 > says: "Characters MUST be represented directly and not by UCHAR."
 >
 > Shouldn't that be something like: "Characters allowed directly in
 > STRING_LITERAL_QUOTE MUST be represented directly and not by UCHAR." ?
Received on Friday, 6 December 2013 12:12:11 UTC

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