get_all_elixir_submodules.ex

def answer_types do
    :code.all_loaded()
    # turn everything into a string
    |> Enum.map(&(elem(&1, 0) |> to_string))
    # take only the modules that are scoped under AnswerType
    |> Enum.filter(&Regex.match?(~r/YourModuleName./, &1))
    # take the last element from the list (i.e ["ModuleParent", "Child"]) 
    |> Enum.map(&(String.split(&1, ".") |> Enum.take(-1)))
    # there may be duplicates
    |> Enum.uniq()
    # there may be nested lists
    |> List.flatten()
end

Thank you so much for this function!

welcome @talismandev!