[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message]

Re: What niche is XQuery targeting?

• To: jonathan.robie@d...
• Subject: Re: What niche is XQuery targeting?
• From: David Carlisle <davidc@n...>
• Date: Thu, 9 Dec 2004 16:34:03 GMT
• Cc: xml-dev@l...
• In-reply-to: <41B87B63.9070900@d...> (message from Jonathan Robie onThu, 09 Dec 2004 11:20:51 -0500)
• References: <E1CcKwt-0000ZR-00@u...> <41B87B63.9070900@d...>

 Why condemn one language because it does use an XML syntax, or condemn 
 the other because it does not? 

The problem with Xquery is not that it doesn't use XML syntax, no one
moans that C doesn't use XML syntax. The problem is that it uses (or one
could say abuses) XML syntax when it isn't XML.
<foo> &#666; </foo>
_looks_ for all the world like XML, and people will put it in XML
documents, or try to write it with XML editors, but if in fact that it
is Xquery rather than XML then things will go wrong, and worryingly they
won't go wrong straight away, they will just go wrong sometimes when you
hit the obscure (or not so obscure)  edge cases where the XML and Xquery
grammars parse the same string in different ways (most of these are
related to entity or character references which expand at completely
different times in XPath-in-XML-attributes or XQuery, even though
superficially these two cases look much the same).

Despite suggestions in a draft of XqueryX to the contrary it really
isn't safe to just "inline" XQuery into an XML document.


  Why condemn one language because it has 
  FLWOR expressions but not templates, or the other because it has 
  templates but not FLWOR expressions?

Because in one case it's losing almost all of the functionality of the
language, but in the other it is (mainly) just a syntax change
substituting xsl:for-each and xsl:variable for FLWOR

David

________________________________________________________________________
This e-mail has been scanned for all viruses by Star. The
service is powered by MessageLabs. For more information on a proactive
anti-virus service working around the clock, around the globe, visit:
http://www.star.net.uk
________________________________________________________________________

• References:
  • RE: What niche is XQuery targeting?
    • From: "Michael Kay" <mike@s...>
  • Re: What niche is XQuery targeting?
    • From: Jonathan Robie <jonathan.robie@d...>

• Prev by Date: RE: What niche is XQuery targeting?
• Next by Date: Re: XSLT syntax (was: Re: What niche is XQuerytargeting?)
• Previous by thread: RE: What niche is XQuery targeting?
• Next by thread: Re: What niche is XQuery targeting?
• Index(es):
  • Date
  • Thread