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

Subject: Re: [xsl] What does //distinct-values(...) mean?
From: "G. Ken Holman g.ken.holman@xxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>
Date: Wed, 8 Apr 2020 13:21:51 -0000
Martin didn't say that it operated on a sequence of strings.

He explained that the "//" operator expands to address a bunch of nodes, and then the distinct-values() function is evaluated from each of those nodes.

XPath is evaluated from left to right and the "//" is evaluated before the distinct-values() function is evaluated.

I hope this helps.

. . . . . . Ken

At 2020-04-08 13:13 +0000, Costello, Roger L. costello@xxxxxxxxx wrote:

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?


-----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)



'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


Contact info, blog, articles, etc. |
Check our site for free XML, XSLT, XSL-FO and UBL developer resources |
Streaming hands-on XSLT/XPath 2 training class @ US$45 (5 hours free) |
Essays (UBL, XML, etc.) |

Current Thread