tco_benchmark.exs

Mix.install([:benchee])

defmodule Test do
  def benchmark() do
    vector1 = Enum.map(1..1536, fn _ -> :rand.uniform() end)
    vector2 = Enum.map(1..1536, fn _ -> :rand.uniform() end)

    Benchee.run(
      %{
        "dot_product_enum" => fn -> dot_product_enum(vector1, vector2) end,
        "dot_product_recursion" => fn -> dot_product_recursion(vector1, vector2) end,
        "dot_product_tco" => fn -> dot_product_tco(vector1, vector2) end
      },
      time: 5,
      memory_time: 2
    )
  end

  def dot_product_enum(vector1, vector2) do
    vector1
    |> Enum.zip(vector2)
    |> Enum.reduce(0, fn {x, y}, acc -> acc + x * y end)
  end

  def dot_product_recursion([], []), do: 0

  def dot_product_recursion([x | vector1], [y | vector2]) do
    x * y + dot_product_recursion(vector1, vector2)
  end

  def dot_product_tco(vec1, vec2, acc \\ 0)
  def dot_product_tco([], [], acc), do: acc

  def dot_product_tco([x | vector1], [y | vector2], acc) do
    dot_product_tco(vector1, vector2, x * y + acc)
  end
end

Test.benchmark()