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RE: [www-ql] <none>

From: Jonathan Robie <Jonathan.Robie@SoftwareAG-USA.com>
Date: Thu, 01 Mar 2001 17:28:17 -0500
Message-Id: <5.0.2.1.0.20010301172139.07c30910@pop.mindspring.com>
To: "Ingo Macherius" <macherius@darmstadt.gmd.de>, <www-ql@w3.org>
At 11:28 PM 2/28/2001 +0100, Ingo Macherius wrote:
> > From: www-ql-request@w3.org [mailto:www-ql-request@w3.org]On Behalf Of
> > Jonathan Robie
>
> > First, our requirements document says that we have to produce an XML
> > representation. I would like to see this be semantically identical to the
> > XQuery representation, so that one could automatically be
> > converted to the  other. Using that approach, they would not be two
>different
> > languages, but > two different syntaxes for the same language.
>
>I'm a bit confused. FLWR-XQuery is syntactic shugar for XML Algebra. And of
>course any other syntax for XML Query is just that, too. Thus semantic
>identity MUST be always given when transforming FLWR-XQuery to XML Query
>Algebra expressions and from there to another syntax. There can not be more
>power in XQuery or any other syntax then there is in the Algebra. I hope I
>got this right ?

I am not sure I understand what you mean by FLWR-XQuery. Do you mean 
XQuery? There is only one language named XQuery, and FLWR is just one of 
the ten or so expression types in XQuery.

I am also not sure that you and I mean the same thing by the phrases 
"semantic sugar" and "semantic identity". If I convert an XQuery expression 
into the algebra, I may not be able to convert back from the algebra to the 
original XQuery expression. If I convert an XQuery expression into the XML 
representation of the parse tree, the information content in the two 
syntaxes is identical.

Jonathan

These are my opinions right now. They may be quite different from the 
opinions of Software AG, the W3C XML Query Working Group, or the opinions 
that I will have after reading and considering your response.
Received on Friday, 2 March 2001 08:48:09 GMT

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