Re: XQuery/XPath 3.1: Node List to Node Set ("distinct

> - If order of the sequence must be maintained, consider fold-left() or
fold-right() I suppose
>   - but test it!

I would definitely prefer the index-of() - based solution: for being:
  -  shortest
  - with least moving parts and surface
  - shown in actual performance measurements to be not slower (actually,
was slightly faster) than the fold - based solutions provided in this thread
  - shown to work with both BaseX and Saxon (while one of the fold-based
solutions was being evaluated incorrectly in Saxon due to a bug)

Thanks Eliot and everyone! Happy New Year!
Dimitre

On Thu, Dec 30, 2021 at 6:46 AM Wendell Piez wapiez@xxxxxxxxxxxxxxx <
xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:

> Hmm....
>
> Takeaways for me seem to be:
>
> - For the operation in question, prefer "$nodes/." or perhaps
> "$nodes/self::node()" or $nodes/self::* as appropriate, plus a comment
> - If order of the sequence must be maintained, consider fold-left() or
> fold-right() I suppose
>   - but test it!
> - except and intersect (to say nothing of union) also have some
> interesting uses and applications
>
> Meanwhile it is very reassuring and an education to see these things
> worked out. This problem actually has real-world applications for me too -
> and the $nodes in question could be documents....
>
> Thanks Eliot! Happy New Year!
> Wendell
>
>
> On Wed, Dec 29, 2021 at 6:25 PM Dimitre Novatchev dnovatchev@xxxxxxxxx <
> xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:
>
>> > No, it doesn't seem to be fixed, Mike's implementation seems to try be
>> > smarter than the spec allows and his own coding assumes :)
>>
>> Seems BaseX rules!
>>
>> And glad to be a contributor to the eventual future improvement of Saxon
>> :)
>>
>> Cheers,
>> Dimitre
>>
>> On Wed, Dec 29, 2021 at 12:17 PM Martin Honnen martin.honnen@xxxxxx <
>> xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:
>>
>>> On 29.12.2021 20:59, Dimitre Novatchev dnovatchev@xxxxxxxxx wrote:
>>> >   document (fragments?) are involved.
>>> >
>>> > Yes, bugs happen...
>>> >
>>> > Just trying to evaluate Dr. Kay's fold-left solution with Saxon
>>> (EE9.1.7
>>> > via Oxygen) I am getting a result of 20 nodes but the correct must be
>>> > just 3 nodes. BaseX correctly evaluates the XPath expression and
>>> > produces the right 3-nodes result.
>>> >
>>> > Xml document:
>>> > <t>
>>> >    <a/>
>>> >    <b/>
>>> >    <c/>
>>> > </t>
>>> >
>>> > XSLT stylesheet:
>>> >
>>> > <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform
>>> > <http://www.w3.org/1999/XSL/Transform>" version="3.0">
>>> >    <xsl:output omit-xml-declaration="yes"/>
>>> >    <xsl:template match="/">
>>> >      <xsl:sequence select=
>>> >        "let $xml := /,
>>> >        $nodes := (/*/a, /*/c, /*/b, /*/a, /*/b, /*/a, /*/c, /*/b, /*/a,
>>> > /*/b,
>>> >        /*/a, /*/c, /*/b, /*/a, /*/b, /*/a, /*/c, /*/b, /*/a, /*/b,
>>> >        /*/a, /*/c, /*/b, /*/a, /*/b, /*/a, /*/c, /*/b, /*/a, /*/b,
>>> >        /*/a, /*/c, /*/b, /*/a, /*/b, /*/a, /*/c, /*/b, /*/a, /*/b,
>>> >        /*/a, /*/c, /*/b, /*/a, /*/b )
>>> >        return
>>> >          $nodes => fold-left((), function($all, $this) {$all, $this
>>> > except $all})"/>
>>> >    </xsl:template>
>>> > </xsl:stylesheet>
>>> >
>>> > Result produced when run with Saxon-EE (and also PE) 9.9.1.7 via
>>> Oxygen:
>>> >
>>> >
>>> <a/><c/><b/><b/><b/><b/><b/><b/><b/><b/><b/><b/><b/><b/><b/><b/><b/><b/><b/><b/>
>>> >
>>> > Evaluating the below expression with Saxon-EE XQuery9.9.1.7 also
>>> > produces the same unexpected result:
>>> >
>>> > let $xml := parse-xml("<t><a/><b/><c/></t>"),
>>> >      $nodes := ($xml/*/a, $xml/*/c, $xml/*/b, $xml/*/a, $xml/*/b,
>>> > $xml/*/a, $xml/*/c, $xml/*/b, $xml/*/a, $xml/*/b, $xml/*/a, $xml/*/c,
>>> > $xml/*/b, $xml/*/a, $xml/*/b, $xml/*/a, $xml/*/c, $xml/*/b, $xml/*/a,
>>> > $xml/*/b, $xml/*/a, $xml/*/c, $xml/*/b, $xml/*/a, $xml/*/b, $xml/*/a,
>>> > $xml/*/c, $xml/*/b, $xml/*/a, $xml/*/b,$xml/*/a, $xml/*/c, $xml/*/b,
>>> > $xml/*/a, $xml/*/b, $xml/*/a, $xml/*/c, $xml/*/b, $xml/*/a, $xml/*/b,
>>> > $xml/*/a, $xml/*/c, $xml/*/b, $xml/*/a, $xml/*/b )
>>> >    return
>>> >      $nodes => fold-left((), function($all, $this) {$all, $this except
>>> > $all})
>>> >
>>> > Hopefully this is fixed in the next versions of Saxon?
>>>
>>> No, it doesn't seem to be fixed, Mike's implementation seems to try be
>>> smarter than the spec allows and his own coding assumes :)
>>>
>>> Saxon-JS 2.3 gets
>>>
>>> <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
>>> version="3.0">
>>>    <xsl:output omit-xml-declaration="yes"/>
>>>    <xsl:template match="/">
>>>      <xsl:sequence select=
>>>        "let $xml := /,
>>>        $nodes := (/*/a, /*/c, /*/b, /*/a, /*/b, /*/a, /*/c, /*/b, /*/a,
>>> /*/b,
>>>        /*/a, /*/c, /*/b, /*/a, /*/b, /*/a, /*/c, /*/b, /*/a, /*/b,
>>>        /*/a, /*/c, /*/b, /*/a, /*/b, /*/a, /*/c, /*/b, /*/a, /*/b,
>>>        /*/a, /*/c, /*/b, /*/a, /*/b, /*/a, /*/c, /*/b, /*/a, /*/b,
>>>        /*/a, /*/c, /*/b, /*/a, /*/b )
>>>        return
>>>          fold-left($nodes, (), function($all, $this) {$all, $this except
>>> $all})"/>
>>>    </xsl:template>
>>> </xsl:stylesheet>
>>>
>>> right but SaxonCS and Saxon HE 10.6 don't.
>>>
>>>
>>>
>>
>> --
>> Cheers,
>> Dimitre Novatchev
>> ---------------------------------------
>> Truly great madness cannot be achieved without significant intelligence.
>> ---------------------------------------
>> To invent, you need a good imagination and a pile of junk
>> -------------------------------------
>> Never fight an inanimate object
>> -------------------------------------
>> To avoid situations in which you might make mistakes may be the
>> biggest mistake of all
>> ------------------------------------
>> Quality means doing it right when no one is looking.
>> -------------------------------------
>> You've achieved success in your field when you don't know whether what
>> you're doing is work or play
>> -------------------------------------
>> To achieve the impossible dream, try going to sleep.
>> -------------------------------------
>> Facts do not cease to exist because they are ignored.
>> -------------------------------------
>> Typing monkeys will write all Shakespeare's works in 200yrs.Will they
>> write all patents, too? :)
>> -------------------------------------
>> Sanity is madness put to good use.
>> -------------------------------------
>> I finally figured out the only reason to be alive is to enjoy it.
>>
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>>
>
>
> --
> ...Wendell Piez... ...wendell -at- nist -dot- gov...
> ...wendellpiez.com... ...pellucidliterature.org... ...pausepress.org...
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>


-- 
Cheers,
Dimitre Novatchev
---------------------------------------
Truly great madness cannot be achieved without significant intelligence.
---------------------------------------
To invent, you need a good imagination and a pile of junk
-------------------------------------
Never fight an inanimate object
-------------------------------------
To avoid situations in which you might make mistakes may be the
biggest mistake of all
------------------------------------
Quality means doing it right when no one is looking.
-------------------------------------
You've achieved success in your field when you don't know whether what
you're doing is work or play
-------------------------------------
To achieve the impossible dream, try going to sleep.
-------------------------------------
Facts do not cease to exist because they are ignored.
-------------------------------------
Typing monkeys will write all Shakespeare's works in 200yrs.Will they write
all patents, too? :)
-------------------------------------
Sanity is madness put to good use.
-------------------------------------
I finally figured out the only reason to be alive is to enjoy it.