Private imports in ruby versus elixir

private_imports.ex

iex(1)> defmodule Foo do
...(1)>   defp bar do
...(1)>     "bar"
...(1)>   end
...(1)> end
iex:2: warning: function bar/0 is unused
{:module, Foo,
 <<70, 79, 82, 49, 0, 0, 3, 168, 66, 69, 65, 77, 69, 120, 68, 99, 0, 0, 0, 94, 131, 104, 2, 100, 0, 14, 101, 108, 105, 120, 105, 114, 95, 100, 111, 99, 115, 95, 118, 49, 108, 0, 0, 0, 4, 104, 2, ...>>,
 {:bar, 0}}
iex(2)> defmodule Derp do
...(2)>   import Foo
...(2)>   def herp do
...(2)>     bar
...(2)>   end
...(2)> end
** (CompileError) iex:5: function bar/0 undefined
    (stdlib) lists.erl:1337: :lists.foreach/2
    (stdlib) erl_eval.erl:669: :erl_eval.do_apply/6
       (iex) lib/iex/evaluator.ex:117: IEx.Evaluator.handle_eval/5

private_imports.rb

[4] pry(main)> module Foo
[4] pry(main)*   private
[4] pry(main)*   def bar
[4] pry(main)*     "bar"
[4] pry(main)*   end
[4] pry(main)* end
=> :bar
[5] pry(main)> class Derp
[5] pry(main)*   include Foo
[5] pry(main)*   def herp
[5] pry(main)*     bar
[5] pry(main)*   end
[5] pry(main)* end
=> :herp
[6] pry(main)> Derp.new.herp
=> "bar"