hugs

defmodule Hugs.Cast do
  def string_to_existing_atom(string) when is_binary(string) do
    {:ok, String.to_existing_atom(string)}
  catch
    :error, :badarg -> {:error, {:unexisting_atom, string}}
  end

  def string_to_existing_atom(atom) when is_atom(atom) do
    {:ok, atom}
  end

  def datetime_from_iso8601(string) when is_binary(string) do
    case DateTime.from_iso8601(string) do
      {:ok, value, _calendar_offset} -> {:ok, value}
      {:error, _} = err -> err
    end
  end

  def datetime_from_iso8601(%DateTime{} = dt) do
    {:ok, dt}
  end

  def datetime_from_iso8601(_string) do
    {:error, "not a string"}
  end

  def in_out(cast_in, cast_out) when is_function(cast_in, 1) and is_function(cast_out, 1) do
  end
end