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Re: minor technical comment on 2.1.3 Syntax of variables [OK?]

From: Dan Connolly <connolly@w3.org>
Date: Thu, 12 Jan 2006 17:50:50 -0600
To: Fred Zemke <fred.zemke@oracle.com>
Cc: public-rdf-dawg-comments@w3.org
Message-Id: <1137109850.19546.469.camel@dirk.w3.org>

On Thu, 2006-01-12 at 09:30 -0800, Fred Zemke wrote:
> 2.1.3 Syntax of variables
> Why permit '$' as a synonym for '?'?  Judging from the examples,
> it seems that you expect people to prefer '?'.  Since every keyboard
> to my knowledge has '?', there seems to be no need to define an alternate
> symbol.

This is another detail that the WG discussed under the puncutationSyntax
issue.
  http://www.w3.org/2001/sw/DataAccess/issues#punctuationSyntax

The history of that issue includes...

  Draft: open issues around '?' use. Dirk-Willem van Gulik 25 Oct 2004
  http://lists.w3.org/Archives/Public/public-rdf-dawg/2004OctDec/0160

[[
...

We believe that allowing developers to access to SPARQL through their
well
known ODBC and JDBC interfaces speeds up adoption considerably.

This allows for a wide range of things; at the low end direct integration
into Microsoft Excel or similar right off the bat - and at the high end
leveraging of fail over interfaces and caches.

Given the already messy situation around vendor specific escaping and the
use of stored procedures or other functions to define escpae characters on
the fly we do not believe that escaping at SQL solves this issue.
Especially as this is more an adoption/curve steepness issue that a hard
tecnical one; everything (but for the *DBC leverage) has work arounds.

With respect to the '?' issue; we therefore propose the following

->	Investigate if it is possible to change/tighten the syntax to
	allow the engine to distinguish between a VAR and QNAME without
	needing the ? prefix.

-> 	Replace the '?' by a '$' or '_' or at the very least allow the use
	of a '$' or '_' as a synomym for the '?'.

...
]]

Please let us know whether you find this explanation satisfactory.

> 
> Fred Zemke
-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
D3C2 887B 0F92 6005 C541  0875 0F91 96DE 6E52 C29E
Received on Thursday, 12 January 2006 23:50:56 GMT

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