Thanks Steven for fixing this. (If you pass them keyword arguments, then they pretty much have to return a > full array, rather than try to be clever and return another range, for > type-stability. e.g. sort(-5:5, by=abs) can't be expressed in terms of a > range.)
At first I didn't understand this, until I came around to understanding that keyword arguments don't participate in dispatch. So it's not possible to specialise on a *particular* keyword. It's all or nothing. I guess this make keyword arguments slightly less useful in some circumstances. For my purpose, I defined my own reverse sort so that I could specialise: sortrev(v::AbstractVector) = sort(v, rev=true) sortrev(r::Range) = issorted(r) ? reverse(r) : r
