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Re: what functions should we include in SPARQL 1.1?

From: Steve Harris <steve.harris@garlik.com>
Date: Tue, 2 Nov 2010 22:25:54 +0000
Cc: SPARQL Working Group <public-rdf-dawg@w3.org>
Message-Id: <483CAC78-976D-4726-AF92-293DE23F3783@garlik.com>
To: Lee Feigenbaum <lee@thefigtrees.net>
It's not in XPath (as far as I can tell), but I'd like a RAND() function, it's incredibly useful, e.g.

SELECT ?s WHERE { ?s a <Foo> } ORDER BY RAND() LIMIT 10

SQL's RAND() returns a floating point number between 0 and 1, which works fine. You can also pass it a constant seed value as an argument, but that always struck me as a bit of a strange way of doing it.

- Steve

On 2010-11-02, at 21:16, Lee Feigenbaum wrote:

> (This email discharges my ACTION-305, http://www.w3.org/2009/sparql/track/actions/305)
> 
> Two months ago we all agreed that we want to move forward with the function library work, and we agreed that we need two things:
> 
> 1) A set of functions to include
> 2) URIs for these functions
> 
> This email is to begin a discussion #1 above. AndyS already did much of this work on the wiki page, so I'm pretty much transplanting that here for discussion. Please reply with either concurrence, suggestions & reasons for things to remove or suggestions & reasons for additional things to include.
> 
> This references functions from http://www.w3.org/TR/xpath-functions/ .
> 
> 
> Numeric functions:
> 
>       6.4.1 fn:abs
>       6.4.2 fn:ceiling
>       6.4.3 fn:floor
>       6.4.4 fn:round
>       6.4.5 fn:round-half-to-even
> 
> String functions:
> 
>       7.3.2 fn:compare
>       7.4.1 fn:concat
>       7.4.3 fn:substring
>       7.4.4 fn:string-length
>       7.4.7 fn:upper-case
>       7.4.8 fn:lower-case
>       7.4.10 fn:encode-for-uri
>       7.5.1 fn:contains     (collation form optional)
>       7.5.2 fn:starts-with
>       7.5.3 fn:ends-with
> 
> DateTime functions:
> 
>       10.4.6 op:dateTime-equal
>       10.4.7 op:dateTime-less-than
>       10.4.8 op:dateTime-greater-than
>       10.5.7 fn:year-from-dateTime
>       10.5.8 fn:month-from-dateTime
>       10.5.9 fn:day-from-dateTime
>       10.5.10 fn:hours-from-dateTime
>       10.5.11 fn:minutes-from-dateTime
>       10.5.12 fn:seconds-from-dateTime
>       10.5.13 fn:timezone-from-dateTime
> 
> Misc functions:
> 
> 	3. fn:error
> 
> 
> Lee
> 
> 
> 

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Received on Tuesday, 2 November 2010 22:26:30 GMT

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