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XQuery & XSLT was RE: Verboseness - XML Syntax for XQuery 1.0 (XQueryX)
- From: Dylan Walsh <Dylan.Walsh@Kadius.Com>
- To: xml-dev@lists.xml.org, www-xml-query-comments@w3.org
- Date: Tue, 19 Jun 2001 12:10:08 +0100
I'd like to respond to a number of comments, and clear up what I believe
is needed. The verboseness is not the issue - XQueryX is not really
meant for human consumption. Instead this is about the normal syntax for
XQuery - consistency with XSLT and whether this concise format should be
available as XML as well as or instead of the text syntax.
There is nothing more confusing than having two similar but subtly
different syntaxes to remember. XQuery serves a different purpose to
XSLT and needs a different syntax to reflect these differences. However,
where the two standards overlap they should be more consistent. In
particular, I believe the XSLT template body format should be used for
query results.
From: Michael Champion [SMTP:mike.champion@softwareag-usa.com]
Sent: Sunday, June 17, 2001 10:38 PM
>Finally, on the question of whether XQuery should be more SQL-like than
>XSLT-like, I think that question is moot: XSLT *is* a fairly
reasonable
>query language, and those who are happy with it will probably be able
to
>get along without XQuery. The whole point of XQuery (as I see it) is to
>provide those who need it with a more SQL-like XML query language.
My understanding of the point of XQuery was that it provides querying
across collections of XML documents, with new features for this task and
better scope for optimization than XSLT.
Making it more "SQL-like" seems pointless to me, as the language is
different anyway, and the model is not relational. It uses different
keywords and different syntax.
-----Original Message-----
From: Jonathan Robie [SMTP:Jonathan.Robie@SoftwareAG-USA.com]
Sent: Saturday, June 16, 2001 11:23 AM
>>True, but I think it should be, or that they should have a human
>>writeable XML syntax available as well.
>How important is this, and why is it important? Why would humans prefer
to
>write queries in an XML syntax?
The users editor can ensure well-formedness.
The syntax for results is itself XML, making it more intuitive.
The syntax for results can be similar to that of XSLT, meaning
programmers only have to learn one syntax.
>>However, I'm not saying that they should use XSLT, just that:
>>1. for the results part of the query, they should adopt the XSLT
>>template body format or something similar.
>
>I think that our element constructors are quite similar to XSLT's
template
>bodies, and more so in the latest Working Draft of XQuery.
They appear to not be well-formed XML in XQuery.
>In this message I argue that ease of use, offering conventional
database
>functionality, optimizability, and strong typing are important reasons
for
>developing XQuery, and these needs are not adequately satisfied by XSLT
1.0.
I am not opposed to XQuery, and I am aware that it provides
functionality distinct from that of XSLT. I am not implying you should
all use XSLT and forget about XQuery. My point is that there are atleast
two areas where they overlap:
1. They select parts of an XML document, specified mostly using XPath.
2. They construct new XML elements by example.
I believe they should try to be consistent in these areas. In some
cases, for (1), this would mean changing XSLT to align with XQuery, as
XQuery is better. In other areas XQuery is merely different. For area
(2), I believe the XSLT format should be used.
It has been stated more than once, that the workings groups are
co-ordinating their efforts for consistency, but based on
http://xmlportfolio.com/xsltuk/slides/ that does not appear to be
working perfectly.