Elixir: Module names with dot and nested modules - are they equivalent?

Question

Are below codes equivalent? As to invoke a module method, in both cases, one will use Utilities.StringUtils.some_method(...)

Nested modules

defmodule Utilities do
   defmodule StringUtils do
   end
end

Modules with dot in the name

defmodule Utilities.StringUtils do
end

Answer 1

Yes and no. The first definition automatically defines an alias based on the module name:

defmodule Utilities do
  defmodule StringUtils do
  end

  # Can access the module as StringUtils
end

While the second:

defmodule Utilities.StringUtils do
  # Cannot access the module as StringUtils
end

Other than that, the code and module defined by both are exactly the same.

Answer 2

Yes, both are translated exactly to the symbol (in Erlang a module is referenced by its symbol):

:"Elixir.Utilities.StringUtils"

There aren't really nested modules in Erlang, it's just something Elixir simulated.