Re: exsl:node-set and Saxon 6.5.5

Ah, now I remember to have read some time ago about
"extension functions are allowed to have side-effects".

The references I found useful
2002-05-18 http://lists.fourthought.com/pipermail/exslt/2002-May/000468.html
2002-11-12 http://www.exslt.org/exsl/functions/node-set/

The implementation of exsl:node-set() in Saxon 6.x is a bit of a hack. A
result tree fragment in Saxon 6.x is a document node, with a special bit set
to say "I am a result tree fragment": this bit artifically disables
operations such as "/" applied to the document node. The effect of
exsl:node-set() is to unset this bit in situ, thus enabling such operations.
A bit dirty, but the XSLT spec allows extension functions to do anything you
like, so it's not technically non-conformant.

Michael Kay
http://www.saxonica.com/

> -----Original Message-----
> From: Manfred Staudinger [mailto:manfred.staudinger@xxxxxxxxx]
> Sent: 21 February 2007 22:21
> To: xsl-list@xxxxxxxxxxxxxxxxxxxxxx
> Subject:  exsl:node-set and Saxon 6.5.5
>
> Hi All,
>
> As I rely heavily on the superb diagnostics of Saxon when
> testing client-side (browser) XSLT 1.0 I would like to
> understand the following.
>
> When I run the stylesheet below with SAXON 6.5.5 (with two
> <xsl:copy-of statements) then the (unexpected) output is
>
> <?xml version="1.0" encoding="utf-8"?>
> <test>
>    <Title>From exsl:node-set($rtf)/a/b:</Title>
>    <b>
>       <c>
>          <d/>
>       </c>
>    </b>
>    <Title>Directly from $rtf/a/b/c:</Title>
>    <c>
>       <d/>
>    </c>
> </test>
>
> However, if I delete the first <xsl:copy-of then I get this
> error message from the other one
>    To use a result tree fragment in a path expression, either
>    use exsl:node-set() or specify version='1.1'
> as I think correctly.
>
> Did I miss something XSLT-wise ?
>
> Regards, Manfred
>
> <?xml version="1.0" encoding="UTF-8" ?>
> <xsl:stylesheet version="1.0"
>       xmlns:exsl="http://exslt.org/common"
>       exclude-result-prefixes="exsl"
>       xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
> <xsl:output indent="yes"/>
>
> <xsl:template match="/">
>       <xsl:variable name="rtf">
>               <a>
>                       <b>
>                               <c>
>                                       <d />
>                               </c>
>                       </b>
>               </a>
>       </xsl:variable>
>       <test>
>               <Title><xsl:text>From
> exsl:node-set($rtf)/a/b:</xsl:text></Title>
>               <xsl:copy-of select="exsl:node-set($rtf)/a/b"/>
>               <Title><xsl:text>Directly from
> $rtf/a/b/c:</xsl:text></Title>
>               <xsl:copy-of select="$rtf/a/b/c"/>
>       </test>
> </xsl:template>
> </xsl:stylesheet>