reverse.ex

defmodule Example do
  def reverse(list, acc \\ [])

  def reverse([], acc) do
    acc
  end

  def reverse([head|tail], acc) do
    reverse(tail, [head | acc])
  end
end

defmodule Example do
  def reverse([head]) do
    [head]
  end

  def reverse([head|tail]) do
    reverse(tail) ++ [head]
  end
end