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Re: Comments on WD-rdf-testcases-20010912

From: Bjoern Hoehrmann <derhoermi@gmx.net>
Date: Tue, 18 Sep 2001 21:48:25 +0200
To: Dave Beckett <dave.beckett@bristol.ac.uk>
Cc: www-rdf-comments@w3.org, barstow@w3.org
Message-ID: <8n7fqtkaq83qgm44532mieob69a6kgiq39@4ax.com>
* Dave Beckett wrote:
>> The specification should clearly state that four characters must follow
>> the \u and eight characters the \U. ...
>
>I thought that was what we wrote:
>  \uxxxx      Hexadecimal digits xxxx encoding character ...
>  \Uxxxxxxxx  Hexadecimal digits xxxxxxxx encoding character ...

That leaves out whether x represents an optional or a required digit...

>[U+10FFFF vs. 0xFFFFFFFF]
>It doesn't say we should exclude code points beyond that range.

Code points beyond U+10FFFF are invalid. I've posted a comment on this
to the www-i18n-comments@w3.org mailing list...

>It is easier to have a fixed size field, since this is meant to be a
>simple format; which is why we require absolute URIs, line-by-line
>handling and other simple structures.  Furthermore, it should be
>useful to retain the chance to expand this field later to encode the
>32 bits if Unicode grew to require that (and there is plenty of
>growth there).

N-Triples should allow characters that can't be represented in RDF?
I don't think so.

>> I _really_ wonder why #20, #3C and #3E should be additionally allowed
>> for absoluteURIs. They have to be URI-escaped, the WD implies I should
>> use
>> 
>>   http://www.example.org/test\u0020case/
>> 
>> instead of 
>> 
>>   http://www.example.org/test%20case/
>> 
>> That's IMO pure nonsense.
>
>It is not nonsense

Unescaping the above string results in an invalid URI reference, thus...

>- it has a meaning - but as I say above, given the
>requirements of CHARMOD in this area, I expect we will change to the
>second example.  Those particular characters are escaped since they
>were used in the syntax: 
>  uriref ::= '<' absoluteURI '>'

As I said, absoluteURI should be the absoluteURI in RFC 2396 as updated
by RFC 2732. The characters ' ', '<' and '>' must not appear literally
inside an absoluteURI.

>> I don't see no need for the trailing '.' character required for each
>> n-triple line.
>
>This is compatibility with the existing N3 format
>  http://www.w3.org/DesignIssues/Notation3 
>which remains useful to retain.

Well, Notation3 is underspecified... refer to my recent comments on
www-rdf-interest@w3.org if you like.

>This N-Triples format is meant to be simple, complete format for
>encoding RDF graphs, compatible with existing tools and is proving
>very useful in our work.

Maybe it would be a good idea to change the name of the Working Draft to
"N-Triples and RDF Test Cases" if it is meant to formally specify
N-Triples.
-- 
Björn Höhrmann { mailto:bjoern@hoehrmann.de } http://www.bjoernsworld.de
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Received on Tuesday, 18 September 2001 15:49:37 GMT

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