tree_transform_keys.ex

defmodule Util.Tree do
  def transform_keys(map, transform) when is_map(map) do
    Map.new(
      Enum.map(map, fn {k, v} ->
        {transform.(k) |> IO.inspect(label: "transformed"), transform_keys(v, transform)}
      end)
    )
  end

  def transform_keys(list, transform) when is_list(list) do
    Enum.map(list, &transform_keys(&1, transform))
  end

  def transform_keys(value, _transform) do
    value
  end
end