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Re: Dealing with empty aggregates?
On Thu, 2011-05-19 at 15:46 +0100, Bryn M. Reeves wrote:
> On 05/19/2011 03:36 PM, Frank Ch. Eigler wrote:
> > The canonical construct doesn't require a hand-maintained flag:
> >
> > probe timer.ms(1000) {
> > if (@count(stuff))
> > printf("Sum of stuff: %d\n", @sum(stuff))
> > else
> > printf("No stuff.")
> > }
>
> Exactly what I was looking for, thanks! A count is not especially useful for the
> stuff I'm looking at (nfsd operations fwiw) and it didn't occur to me to gate on
> count (obvious really since it's the only one defined on an empty aggregate.. duh!).
>
> Cheers,
> Bryn.
Another way: If all you're interested in is the sum, then you can
initialize it with
stuff <<< 0
and then it'll never be empty.
Jim