Indeed this suggests a generalization using higher-order functions:
<xsl:function name="has-duplicates" as="xs:boolean">
<xsl:param name="nodes" as="node()*"/>
<xsl:param name="hashCode" as="function(node()) as xs:anyAtomicType"/>
<xsl:param name="equals" as="function(node(), node()) as xs:boolean"/>
<xsl:variable name="groups" as="map(xs:string, node()*)"
select="map:merge($nodes ! map{$hashCode(.) : .},
map{'duplicates':'combine'})"/>
<xsl:sequence select="some $k in map:keys($groups) satisfies
( let $g := $groups($k) return
count($g) gt 1 and some $i in $g, $j
in ($g except $i) satisfies $equals($i, $j) )"/>
</xsl:function>
so you can supply the functions for computing signatures and determining node
equality as parameters.
Michael Kay
Saxonica
On 21 Jan 2020, at 15:42, Piez, Wendell A. (Fed)
wendell(_dot_)piez(_at_)nist(_dot_)gov
<xsl-list-service(_at_)lists(_dot_)mulberrytech(_dot_)com> wrote:
Hi,
Another solution not yet suggested in this thread is to avoid deep-equal()
and rely on a signature function.
So for example,
<xsl:function name="f:signature" as="xs:string">
<xsl:param name="who" as="node()"/>
<xsl:value-of select="string-join($who/(first, last), ' ')"/>
</xsl:function>
Then your list of author-directors is
//author[f:signature(.)=parent::film/child::director/f:signature(.)]
(Or the other way around.)
Wrap the expression in the filter in not() to retrieve authors who did not
direct, etc.
One advantage of this approach is it's easy to adjust the signature logic to
real-world exigencies.
Cheers, Wendell
-----Original Message-----
From: Wolfhart Totschnig
wolfhart(_dot_)totschnig(_at_)mail(_dot_)udp(_dot_)cl
<xsl-list-service(_at_)lists(_dot_)mulberrytech(_dot_)com>
Sent: Sunday, January 19, 2020 4:22 PM
To: xsl-list(_at_)lists(_dot_)mulberrytech(_dot_)com
Subject: Re: [xsl] compare two node sets
Thank you, David, Michael, and Liam for the prompt replies! Michael's
solution seems to be the simplest to implement. I use Saxon 9 HE, so XPath
2.0 should be okay. And, indeed, quadratic performance should not be an
issue. However, Saxon throws the following error:
XPST0003: Unexpected token "every" at start of expression
Is there a typo in the expression? I used the expression as given:
<xsl:when test="count(//director) eq count(//author) and every $d in
//director satisfies some $a in //author satisfies deep-equal($d/*, $a/*)">
To clarify, the context node is the <film> element.
Wolfhart
On 19.01.20 17:55, Liam R. E. Quin liam(_at_)fromoldbooks(_dot_)org wrote:
On Sun, 2020-01-19 at 20:37 +0000, Wolfhart Totschnig
wolfhart(_dot_)totschnig(_at_)mail(_dot_)udp(_dot_)cl wrote:
Hello,
I have an XSL/XPath problem to which I cannot find the solution. I
have an xml file with data about films, in the following form
(simplified):
[..]
. By contrast, in the following example the test should return
<false>:
<film>
<title>M</title>
<director>
<first>Fritz</first>
<last>Lang</last>
</director>
<author>
<first>Thea von</first>
<last>Harbou</last>
</author>
<author>
<first>Fritz</first>
<last>Lang</last>
</author>
</film>
Why?
As stated,
<xsl:mode on-no-match="shallow-copy" />
<xsl:template match="/">
<xsl:apply-templates select="/films/film[
some $a in author satisfies
(
($a/first = director/first)
and ($a/last = director/last)
)
]"/>
</xsl:template>
Liam
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