Elixir binary parsing test

test_binary_parse.exs

defmodule Foo do
  def foo1(bin, arg \\ 0) do
    case do_foo1(bin) do
      {:end, bin} = r ->
        {r, arg}
      {a, rest} ->
        foo1(rest, arg + 1)
    end
  end

  def do_foo1(<<a::8, rest::bits>>) do
    {a, rest}
  end

  def do_foo1(_) do
    {:end, <<>>}
  end


  def foo2(bin, times \\ 0) do
    do_foo2(bin, times)
  end

  def do_foo2(<<a::8, rest::bits>>, times) do
    do_foo2(rest, times + 1)
  end

  def do_foo2(_, times) do
    {:end, times}
  end
end

IO.inspect Foo.foo1(String.duplicate(<<1>>, 10240))
IO.inspect Foo.foo2(String.duplicate(<<1>>, 10240))
start = System.monotonic_time(:millisecond)
Enum.each(1..1000, fn _ ->
  Foo.foo1(String.duplicate(<<1>>, 10240))
end)
finish = System.monotonic_time(:millisecond)
IO.puts "Slow avg for 10KB: #{finish - start}ms"

start = System.monotonic_time(:millisecond)
Enum.each(1..1000, fn _ ->
  Foo.foo2(String.duplicate(<<1>>, 10240))
end)
finish = System.monotonic_time(:millisecond)
IO.puts "Fast avg for 10KB: #{finish - start}ms"