Re: [xsl] XQuery/XPath 3.1: Node List to Node Set ("distinct nodes")

["Dimitre Novatchev dnovatchev@xxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

A pure XPath solution:

let $ids := distinct-values($nodes ! generate-id(.))
   return  $ids ! (function($id) {$nodes[generate-id(.) eq $id][1]})(.)

Happy New Year to all !

On Tue, Dec 28, 2021 at 2:39 PM Wendell Piez wapiez@xxxxxxxxxxxxxxx <
xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:

> Eliot and XSL-List,
>
> Along similar lines to $nodes | (), consider
>
> $nodes except ()
> $nodes intersect $nodes
>
> I'm finding it difficult to argue what's most intuitive but I kind of like
> 'intersect'. Can't vouch for performance though. :-)
>
> Best wishes for 2022 --
> Wendell
>
>
>
>
> On Tue, Dec 28, 2021 at 4:56 PM Michael Kay mike@xxxxxxxxxxxx <
> xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:
>
>> You might consider
>>
>> $nodes | ()
>>
>> a bit more intuitive.
>>
>> Michael Kay
>> Saxonica
>>
>> On 28 Dec 2021, at 19:23, Eliot Kimber eliot.kimber@xxxxxxxxxxxxxx <
>> xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:
>>
>> Hmph.
>>
>> That is certainly much more efficient p
 but is not necessarily obvious
>> (at least not to me).
>>
>> Thanks!
>>
>> E.
>>
>> _____________________________________________
>> *Eliot Kimber*
>> Sr Staff Content Engineer
>> O: 512 554 9368
>>
>> M: 512 554 9368
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>>
>> *From: *Martin Honnen martin.honnen@xxxxxx <
>> xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>
>> *Date: *Tuesday, December 28, 2021 at 1:15 PM
>> *To: *xsl-list@xxxxxxxxxxxxxxxxxxxxxx <xsl-list@xxxxxxxxxxxxxxxxxxxxxx>
>> *Subject: *Re: [xsl] XQuery/XPath 3.1: Node List to Node Set ("distinct
>> nodes")
>>
>> [External Email]
>>
>>
>> On 28.12.2021 20:10, Eliot Kimber eliot.kimber@xxxxxxxxxxxxxx wrote:
>> > I couldnbt find an answer in my google and markmail searching so I
>> > thought Ibd ask here:
>> >
>> > Given an arbitrary list of nodes that may contain duplicates, what is
>> > the most efficient way to reduce the node list to a set?
>> >
>> > The solution I came up with is a recursive function:
>> >
>> > (:
>> >
>> > Get the unique nodes from the supplied sequence
>> >
>> > @param nodes The sequence of nodes to evaluate
>> >
>> > @return A sequence of nodes such that each node in $nodes exists exactly
>> > once.
>> >
>> > :)
>> >
>> > declare function dutils:distinctNodes($nodes as node()*) as node()* {
>> >
>> >    dutils:_getDistinctNodes($nodes, ())
>> >
>> > };
>> >
>> > declare function dutils:_getDistinctNodes($nodes as node()*, $resultList
>> > as node()*) as node()* {
>> >
>> >    if (exists($nodes))
>> >
>> >    then
>> >
>> >    let $node := head($nodes)
>> >
>> >    return dutils:_getDistinctNodes(tail($nodes), ($resultList | $node))
>> >
>> >    else $resultList
>> >
>> > };
>> >
>> > Which works but I feel like Ibm missing some obvious way to do this
more
>> > directly, but Ibm not seeing it.
>> >
>> > Am I missing a better solution?
>>
>> $nodes/.
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>
>
> --
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--
Cheers,
Dimitre Novatchev
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