defmodule Main do
  def traverse(name \\ "", struct)
  def traverse(root, map) when is_map(map), do: Enum.each(map, fn {key, value} -> traverse("#{root}.#{key}", value) end)
  def traverse(key, value), do: IO.puts "#{key} --> #{value}"

  def main do
    traverse(%{a: 1, b: %{c: 2, d: %{e: 3, f: 4}}})
  end
end

Main.main