W3C home > Mailing lists > Public > w3c-rdfcore-wg@w3.org > July 2001

Re: N-Triples V1.6 Character Encoding and Escaping

From: pat hayes <phayes@ai.uwf.edu>
Date: Thu, 26 Jul 2001 13:51:58 -0700
Message-Id: <v04210108b78631ca0081@[130.107.66.237]>
To: Graham Klyne <Graham.Klyne@Baltimore.com>
Cc: w3c-rdfcore-wg@w3.org
>At 12:22 PM 7/25/01 +0100, Dave Beckett wrote:
>>One way to escape a character.  Check.
>>
>>  [[* Explicit end delimiters MUST be provided. Escapes such as
>>  \uABCD where the end delimiter is a space or any character other
>>  than [01-9A-F] SHOULD be avoided: it is not clear visually, and it
>>  can cause an editor to insert spurious line-breaks when
>>  word-wrapping on spaces. Forms like SPREAD's &UABCD; [SPREAD] or
>>  XML's &#xhhhh;, where the escape is explicitly terminated by a
>>  semicolon, are much better. Escaped characters SHOULD be
>>  acceptable wherever unescaped characters are. In particular, they
>>  SHOULD be acceptable in identifiers and comments.
>>  ]]
>>
>>Oh dear; the python style things \uABCD are mentioned as should be
>>avoided.  This is only a recommendation though.
>>
>>So I propose we provide one way to escape:
>>  '\u' [A-Fa-f0-9]{1,8} ';'
>>which generates the appropriate Unicode code point from 1-8 hex digits.
>
>Which falls foul of another rule, i.e. inventing a new escaping 
>mechanism.  (I assert that adding the ';' terminator changes the 
>escape mechanism.)
>
>It is not clear to me that a fixed-length form like \uxxxx or 
>\Uxxxxxxxx actually breaks the rule given above:  it depends on 
>one's interpretation of "delimiter":  counting is a well-established 
>way of delimiting values in some kinds of structure.

I concur. My reading of the rule is that the use of a special 
character as an 'end' delimiter should be avoided.

BTW, are N-triples really only an in-group convenience, or are people 
thinking that we are going to endorse it as a public standard? If so, 
I would like to reconsider the line-oriented nature of the syntax, 
which strikes me as being archaic for a serious standard these days, 
and will break immediately the language is extended to anything more 
complicated.

Pat

---------------------------------------------------------------------
(650)859 6569 w
(650)494 3973 h (until September)
phayes@ai.uwf.edu 
http://www.coginst.uwf.edu/~phayes
Received on Thursday, 26 July 2001 16:51:49 EDT

This archive was generated by hypermail pre-2.1.9 : Wednesday, 3 September 2003 09:38:18 EDT