elixirplayground.com code share

code.exs

defmodule Crutches.Map do
  def deep_key_change(map, fun), do: deep_key_change(map, fun, %{})
  def deep_key_change(map, _, acc) when map == %{}, do: acc
  def deep_key_change(map, fun, acc) do
    map
    |> Enum.reduce acc, fn(submap, akk) ->
      case submap do
        {key, value} when is_map(value) -> 
          Map.put(akk, fun.(key), deep_key_change(value, fun, %{}))
        {key, value} ->
          Map.put(akk, fun.(key), value)
      end
    end
  end
end

map1 = %{"hello" => %{"goodbye" => 1}, "akuna" => "matata"}
map2 = %{"hello" => %{"goodbye" => 1, "akuna" => "matata", "hello" => %{"goodbye" => 1, "akuna" => "matata"}}, "akuna" => "matata"}

map1 |> Crutches.Map.deep_key_change(fn(key) -> String.to_atom(key) end) |> inspect |> IO.puts
map2 |> Crutches.Map.deep_key_change(fn(key) -> String.to_atom(key) end) |> inspect |> IO.puts