It's actually giving different results under Saxon-B and Saxon-SA (the join
optimizer in Saxon-SA is kicking in and getting something wrong). I'll look
into it.

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

> -----Original Message-----
> From: alan.painter@xxxxxxxxx [mailto:alan.painter@xxxxxxxxx] 
> Sent: 11 May 2006 17:30
> To: xsl-list@xxxxxxxxxxxxxxxxxxxxxx
> Subject:  surprised about the results of a filter 
> expression in XSLT2.0
> 
> I'm surprised to see that a filter expression, applied in 
> this case to a variable, produces more elements in the result 
> than there are elements in the variable.  In this case, it 
> produces the cartesian product of the number of elements in 
> the variable and the number of combinations in the list that 
> comprises the predicate.  I'm assuming that this is normal.
> Where can I find this behavio(u)r described in the XSLT spec? 
>  Thanks for any pointers.
> 
> In Saxon 8.7.1 (perhaps elsewhere but haven't tested), in the 
> below stylesheet, the instruction
> 
>       <xsl:copy-of select="$idElements[@id=$hrefs]"/>
> 
> produces
> 
>    <idElement id="_123"/>
>    <idElement id="_123"/>
>    <idElement id="_123"/>
>    <idElement id="_456"/>
>    <idElement id="_456"/>
>    <idElement id="_456"/>
> 
> whereas the instruction
> 
>       <xsl:copy-of select="$idElements[@id=distinct-values($hrefs)]"/>
> 
> produces
> 
>    <idElement id="_123"/>
>    <idElement id="_456"/>
> 
> Here's the stylesheet
> 
> <?xml version="1.0" encoding="UTF-8"?>
> 
> <xsl:stylesheet xmlns:xs="http://www.w3.org/2001/XMLSchema"
>                 xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
>                 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
>                 version="2.0">
> 
>       <xsl:output method="xml" encoding="ISO-8859-1" indent="yes"/>
> 
>       <xsl:variable name="testdoc">
>             <root>
>                   <refElement name="element1"> <ref 
> href="_123"/> </refElement>
>                   <refElement name="element2"> <ref 
> href="_123"/> </refElement>
>                   <refElement name="element3"> <ref 
> href="_123"/> </refElement>
>                   <refElement name="element4"> <ref 
> href="_456"/> </refElement>
>                   <refElement name="element5"> <ref 
> href="_456"/> </refElement>
>                   <refElement name="element6"> <ref 
> href="_456"/> </refElement>
>                   <idElement id="_123"/>
>                   <idElement id="_456"/>
>                   <idElement id="_789"/>
>             </root>
>       </xsl:variable>
> 
>       <xsl:variable name="idElements" select="$testdoc//idElement"/>
> 
>       <xsl:template match="/">
>             <xsl:apply-templates select="$testdoc" mode="inTestDoc"/>
>       </xsl:template>
> 
>       <xsl:template match="*" mode="inTestDoc">
>             <xsl:variable name="hrefs" as="xs:string*"
> select="$testdoc//@href"/>
>             <xsl:copy>
>                   <!-- Case 1 -->
>                   <xsl:copy-of select="$idElements[@id=$hrefs]"/>
>                   <!-- Case 2 -->
>                   <!-- <xsl:copy-of
> select="$idElements[@id=distinct-values($hrefs)]"/> -->
>             </xsl:copy>
>       </xsl:template>
> 
> </xsl:stylesheet>
> 
> Output of case 1:
> 
> <?xml version="1.0" encoding="ISO-8859-1"?> <root 
> xmlns:xs="http://www.w3.org/2001/XMLSchema"
>       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
>    <idElement id="_123"/>
>    <idElement id="_123"/>
>    <idElement id="_123"/>
>    <idElement id="_456"/>
>    <idElement id="_456"/>
>    <idElement id="_456"/>
> </root>
> 
> Output of case 2:
> 
> <?xml version="1.0" encoding="ISO-8859-1"?> <root 
> xmlns:xs="http://www.w3.org/2001/XMLSchema"
>       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
>    <idElement id="_123"/>
>    <idElement id="_456"/>
> </root>
> 
> -alan
> **************************************************************
> ***********
> This message and any attachments (the "message") are 
> confidential and intended solely for the addressee(s).
> Any unauthorised use or dissemination is prohibited. E-mails 
> are susceptible to alteration.   
> Neither SOCIETE GENERALE nor any of its subsidiaries or 
> affiliates shall be liable for the message if altered, 
> changed or falsified.
>                               ************ Ce message et 
> toutes les pieces jointes (ci-apres le "message") sont 
> confidentiels et etablis a l'intention exclusive de ses 
> destinataires. Toute utilisation ou diffusion non autorisee 
> est interdite. Tout message electronique est susceptible 
> d'alteration. 
> La SOCIETE GENERALE et ses filiales declinent toute 
> responsabilite au titre de ce message s'il a ete altere, 
> deforme ou falsifie.
> **************************************************************
> ***********