- From: Tim Berners-Lee <timbl@w3.org>
- Date: Sun, 25 Nov 2007 20:04:45 -0500
- To: Dan Brickley <danbri@danbri.org>
- Cc: Public CWM <public-cwm-talk@w3.org>, Ivan Herman <ivan@w3.org>, Dave Beckett <dave@dajobe.org>, Eric Prud'hommeaux <eric@w3.org>
>
> One thing I was thinking about, comparing with SPARQL
> is the difference in quoting for literals. SPARQL allows
> 'foo' and '''foo''' as well as "foo" and """foo"" but
> Turtle only uses double quotes. I need more information
> on whether to add this, does this causes N3/cwm problems?
>
Cwm has always had triple-double-quote, which are like python and, I
think,
invaluable for multi-line strings.
The single quotes and back quotes were reserved.
I wish they had been reserved in SPARQL too.
It is the sort of thing that, once you've allowed them, you can't
reclaim them --
and then you find you want to extend the language and you are hosed as
you have no characters left.
Single quotes could for example be used as:
- a different sort for string, one in which variable substitution occurs
as in { ?x name ?y; phone ?z } => { 'You can call $y on the phone
at $z for more information' }.
- Nested quotes of some form with backquote, such as `foaf:Person'
meaning the string of the URI of that symbol, as in myStatemet
rdf:predicateURI `foaf:knows'.
- Embedding XML as a shorter syntax for XML literals
foo s:comment '<em>Don't try this at home</em>'
etc
What do people think? The SPARQL design seems to have been to just
use up the language space with no thought for the future expansion.
Also using up the $sign as a synonym for ?.
Tim
> The other SPARQL issue to consider is the allowed
> characters in prefixed names. SPARQL has slightly
> different rules that allow numbers and '.'s in different
> places.
>
> See
> Turtle - Terse RDF Triple Language 20 November 2007
> http://www.dajobe.org/2004/01/turtle/
>
> All changes:
> http://www.dajobe.org/2004/01/turtle/#sec-changelog
>
> Dave
>
>
>
>
Received on Monday, 26 November 2007 01:05:06 UTC