Actually, the spec of fn:function-lookup says:
If the arguments to fn:function-lookup identify a function that is present in
the static context of the function call, the function will always return the
same function that a static reference to this function would bind to. If there
is no such function in the static context, then the results depend on what is
present in the dynamic context, which is ·implementation-defined·.
I seem to recall there was a fair bit of discussion about situations that might
lead to the dynamic context containing functions not present in the static
context, but I don't recall the details - I think a number of people had
different reasons for suggesting this could be useful. For Saxon, certainly,
it's useful not to have to impose what would be a completely artificial
restriction.
Michael Kay
Saxonica
On 16 Jan 2017, at 14:35, Martin Honnen martin(_dot_)honnen(_at_)gmx(_dot_)de
<xsl-list-service(_at_)lists(_dot_)mulberrytech(_dot_)com> wrote:
Both the latest internal draft of the XSLT 3.0 spec in
https://www.w3.org/XML/Group/qtspecs/specifications/xslt-30/html/#dynamic-xpath
as well as the official https://www.w3.org/TR/xslt-30/#element-evaluate say
about the function signatures in the context of dynamic XPath evaluation
using xsl:evaluate: "Note that this set deliberately excludes XSLT-defined
functions in the standard function namespace".
Based on that I would expect the XSLT "document" function not to be available
in dynamic XPath evaluation using xsl:evaluate. So I wrote a test case doing
<xsl:stylesheet version="3.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform";
xmlns:xs="http://www.w3.org/2001/XMLSchema";
xmlns:fn="http://www.w3.org/2005/xpath-functions";
xmlns:math="http://www.w3.org/2005/xpath-functions/math";
xmlns:array="http://www.w3.org/2005/xpath-functions/array";
xmlns:map="http://www.w3.org/2005/xpath-functions/map";
exclude-result-prefixes="array fn map math xs">
<xsl:output method="xml"/>
<xsl:template name="main" match="/">
<xsl:sequence
select="
let $f := function-lookup(xs:QName('fn:document'), 1)
return
if (exists($f)) then
$f('')
else
'not found'"/>
<xsl:variable name="path" as="xs:string">
let $f := function-lookup(xs:QName('fn:document'), 1)
return
if (exists($f)) then
$f('')
else
'not found'</xsl:variable>
<xsl:evaluate xpath="$path"/>
</xsl:template>
</xsl:stylesheet>
and expected that to return the stylesheet code for the xsl:sequence and 'not
found' for the xsl:evaluate.
However, only Exselt gives me that result, both Saxon 9.7 EE as well as
Altova XMLSpy return the stylesheet code twice which seems to indicate they
make the 'document' function available to xsl:evaluate. Isn't that a bug? Or
does the spec need to allow it if an implementer wants to go beyond pure
XPath support?
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