types.ex

defmodule Types do
  def typeof(nil), do: nil
  def typeof(false), do: false
  def typeof(true), do: true
  def typeof(atom) when is_atom(atom) do
    if function_exported?(atom, :__info__, 1) || Code.ensure_loaded?(atom) do
      if function_exported?(atom, :__struct__, 0), do: :struct, else: Module
    else
      Atom
    end
  end
  def typeof(list) when is_list(list) do
    if Keyword.keyword?(list), do: Keyword, else: List
  end
  def typeof(string) when is_binary(string) or is_bitstring(string), do: String
  def typeof(number) when is_integer(number), do: Integer
  def typeof(float) when is_float(float), do: Float
  def typeof(tuple) when is_tuple(tuple), do: Tuple
  def typeof(function) when is_function(function), do: Function
  def typeof(pid) when is_pid(pid), do: Process
  def typeof(port) when is_port(port), do: Port
  def typeof(reference) when is_reference(reference), do: :reference
  def typeof(%{__struct__: exception_struct} = exception) when is_exception(exception), do: exception_struct
  def typeof(exception) when is_exception(exception), do: Exception
  def typeof(%{__struct__: struct}), do: struct
  def typeof(struct) when is_struct(struct), do: :struct
  def typeof(map) when is_map(map), do: Map
  def typeof(_), do: :unknown
end