Thanks, that works! One question below, though: On Mon, 2013-03-25 at 18:32 +0000, Siwek, Jonathan Luke wrote: > function histogram_default(index: count): count > { > return 0; > } > > const new_histogram: HistogramType = table() &default=histogram_default; Why not just do &default=0 instead of histogram_default? That works for me.