Re: [xsl] What does //distinct-values(...) mean?

["Costello, Roger L. costello@xxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

Hi Martin,

But, but, but, ...

I thought that // operates on nodes. The distinct-values function doesn't
return nodes, does it? I thought it returns a sequence of strings. If so, then
how can // operate on a sequence of strings?

/Roger

-----Original Message-----
From: Martin Honnen martin.honnen@xxxxxx
<xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>
Sent: Wednesday, April 8, 2020 8:25 AM
To: xsl-list@xxxxxxxxxxxxxxxxxxxxxx
Subject: [EXT] Re: [xsl] What does //distinct-values(...) mean?

Am 08.04.2020 um 14:19 schrieb Costello, Roger L. costello@xxxxxxxxx:
> Hi Folks,
>
> I executed this XPath query in Oxygen:
>
> //distinct-values(//Row[matches(Advertiser, 'TS3', 'i')]/Subscribers)
>
> The two slashes at the beginning were an accident. At the bottom of the
screen Oxygen shows the matches. All of a sudden it showed 111,000 matches,
then a moment later 438,000 matches, and then finally 525,946 matches.
>
> "Yikes!" I thought, "What is going on? There is supposed to be around 17
matches. How can there be half a million matches?"
>
> Then I saw the two slashes at the start.
>
> "Hmm, what is the meaning of two slashes preceding the distinct-values
function?" I thought.
>
> So, I ask you: what is the meaning of two slashes preceding the
distinct-values function? Why does its evaluation result in so many matches?

// is short for /descendant-or-self::node()/ so
   //distinct-values(//Row[matches(Advertiser, 'TS3', 'i')]/Subscribers)
is
   /descendant-or-self::node()/distinct-values(//Row[matches(Advertiser,
'TS3', 'i')]/Subscribers)
meaning it returns
   distinct-values(//Row[matches(Advertiser, 'TS3', 'i')]/Subscribers)
as many times as the document has any nodes selectable by
/descendant-or-self::node().