map_bench.ex

defmodule MapBench do
  use Benchfella

  def map_cons([], _fun), do: []
  def map_cons([head | tail], fun), do: [fun.(head) | map_cons(tail, fun)]

  def map_recurse(list, fun, acc \\ [])
  def map_recurse([], _fun, acc), do: :lists.reverse(acc)
  def map_recurse([head | tail], fun, acc), do: map_recurse(tail, fun, [fun.(head) | acc])

  def map_for(list, fun), do: for i <- list, do: fun.(i)

  @list100 1..100 |> Enum.to_list
  @list1000 1..1000 |> Enum.to_list
  @list10000 1..10000 |> Enum.to_list
  @list100000 1..100000 |> Enum.to_list

  bench "cons 100" do
    @list100 |> map_cons(fn x -> x * 2 end)
  end

  bench "cons 1000" do
    @list1000 |> map_cons(fn x -> x * 2 end)
  end

  bench "cons 10000" do
    @list10000 |> map_cons(fn x -> x * 2 end)
  end

  bench "cons 100000" do
    @list100000 |> map_cons(fn x -> x * 2 end)
  end

  bench "recurse 100" do
    @list100 |> map_recurse(fn x -> x * 2 end)
  end

  bench "recurse 1000" do
    @list1000 |> map_recurse(fn x -> x * 2 end)
  end

  bench "recurse 10000" do
    @list10000 |> map_recurse(fn x -> x * 2 end)
  end

  bench "recurse 100000" do
    @list100000 |> map_recurse(fn x -> x * 2 end)
  end

  bench "for 100" do
    @list100 |> map_for(fn x -> x * 2 end)
  end

  bench "for 1000" do
    @list1000 |> map_for(fn x -> x * 2 end)
  end

  bench "for 10000" do
    @list10000 |> map_for(fn x -> x * 2 end)
  end

  bench "for 100000" do
    @list100000 |> map_for(fn x -> x * 2 end)
  end
end