Elixir recursion comparision

Mix.install([
  {:benchee, "~> 1.0"}
])

defmodule TestRecursion do
  def sum([]), do: 0
  def sum([h|t]), do: h + sum(t)
end

defmodule TestTailRecursion do
  def sum(list, acc \\ 0)
  def sum([], acc), do: acc
  def sum([h|t], acc), do: sum(t, acc + h)
end

list = Stream.repeatedly(fn -> :rand.uniform(50) end) |> Enum.take(10_000)

Benchee.run(
  %{
    "sum recursion" => fn -> TestRecursion.sum(list) end,
    "sum tail recursion" => fn -> TestTailRecursion.sum(list) end
  },
  time: 10,
  memory_time: 2
)