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

Re: why is "(chapter//footnote)[1]" illegal?

Subject: Re: why is "(chapter//footnote)[1]" illegal?
From: "Dimitre Novatchev" <dnovatchev@xxxxxxxxx>
Date: Sat, 23 Aug 2003 18:21:08 +0200
chapter footnote
"Robert P. J. Day" <rpjday@xxxxxxxxxxxxxx> wrote in message
news:Pine.LNX.4.44.0308230904470.1866-100000@xxxxxxxxxxxxxxxxxxxxxxxx
>
>   boning up on my predicates and patterns, i'm reading
> kay, p. 443, which states:
>
>   "(chapter//footnote)[1] is not a valid pattern.  (Why not?
> No good reason, it's just that the spec doesn't allow it."

It cannot be derived from the syntax of "Patterns" as specified in

http://www.w3.org/TR/xslt#patterns

If you remove the brackets you'll get a valid match pattern.

>
>   but on p. 408, there is an explanation of the (apparently
> acceptable) path expression "(chapter/para)[1]".
>
>   so is it just the difference between using the child axis
> and the descendant-or-self axis?  it's not obvious to me
> why the first should be illegal while the second is legal.

Because the first is illegal *pattern* (it is a legal XPath expression).

Patterns are a strict subset of XPath expressions.

Patterns were introduced (in my opinion) to allow for some optimization
opportunities as well as for sanity in the template matching and
instantiation process.


So, the brief answer is: Because patterns are not the same as XPath
expressions.



=====
Cheers,

Dimitre Novatchev.
http://fxsl.sourceforge.net/ -- the home of FXSL




 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list


Current Thread

PURCHASE STYLUS STUDIO ONLINE TODAY!

Purchasing Stylus Studio from our online shop is Easy, Secure and Value Priced!

Buy Stylus Studio Now

Download The World's Best XML IDE!

Accelerate XML development with our award-winning XML IDE - Download a free trial today!

Don't miss another message! Subscribe to this list today.
Email
First Name
Last Name
Company
Subscribe in XML format
RSS 2.0
Atom 0.3
Site Map | Privacy Policy | Terms of Use | Trademarks
Free Stylus Studio XML Training:
W3C Member
Stylus Studio® and DataDirect XQuery ™are products from DataDirect Technologies, is a registered trademark of Progress Software Corporation, in the U.S. and other countries. © 2004-2013 All Rights Reserved.