The thing that gets me is that the first argument is the argument that is overwritten in memory as the return value. Since the return value would be placed in memory location one, which is the same as the first argument I would assume that you would get a small performance difference in favor of swapping the order from the current implementation.
We would only get the benefit of the argument pattern if we changed Erlang since Enum.reduce/3 delegates straight to :list.foldl/3 id the first argument is a list.
I haven’t tested this so I’m speculating. It is what I do.
