Elixir tuple map function

gistfile1.ex

  # Map over a tuple in normal order
  def tuple_map1(tuple, function), do:
    tuple_map(tuple, function, 0, [])

  def tuple_map1(tuple, function, index, acc) when index < tuple_size(tuple) do
    item = function.(elem(tuple, index))
    tuple_map1(tuple, function, index + 1, [item | acc])
  end
  def tuple_map1(tuple, function, index, acc) do
    Enum.reverse(acc)
  end

  # Map over a tuple in inverse order to avoid reversing the list
  def tuple_map2(tuple, function), do:
    tuple_map(tuple, function, tuple_size(tuple), [])

  def tuple_map2(tuple, function, index, acc) when index > 0 do
    item = function.(:erlang.element(index, tuple))
    tuple_map2(tuple, function, index - 1, [item | acc])
  end
  def tuple_map2(tuple, function, index, acc) do
    acc
  end