Proof of concept?

bubble.ex

defmodule Dialog do

  ## grove vertaling van:
  # dialog main do
  #  say "Hello"
  #  say "How are you?"
  #  ask "What is your name?"
  #  say "Hello #{answer}!""
  # end
  #
  # dialog trigger: "hi|hello" do
  #  say "Hello to you too!"
  # end

  # dialog main do
  def main(parent) do

    say("Hello", parent, 2000)
    say("How are you?", parent, 400)
    {:ok, answer} = ask("What is your name", parent, :infinity)
    say("Hello #{answer}!", parent, 400)

    stop(parent)
  end

  # dialog trigger: "hello|hi"
  def hello(message, parent) do
    say("Hello there to you too!", parent, 400)
  end

  defp dialog_matcher({:text, message}, parent) do
    cond do
      Regex.match?(~r/hello|hi/, message) ->
        hello(message, parent)
    end
  end

  defp say(message, parent, timeout) do
    send parent, {:message, message}
    receive do
      message ->
        dialog_matcher(message, parent)
    after
      timeout ->
        :ok
    end
  end

  defp ask(message, parent, timeout) do
    send parent, {:message, message}
    receive do
      {:text, text} ->
        {:ok, text}
    after
      timeout ->
        {:ok, nil}
    end
  end

  defp stop(parent) do
    send parent, :stop
  end

end

defmodule Runner do
  def run(dialog) do
    parent = self()
    bot = spawn(fn -> dialog.main(parent) end)
    spawn(fn -> input_loop(bot) end)
    output_loop()
  end

  defp output_loop do
    receive do
      {:message, message} ->
        IO.puts message
        output_loop()
      :stop -> :ok
    end
  end

  defp input_loop(bot) do
    text = IO.gets("") |> String.trim()
    send bot, {:text, text}
    input_loop(bot)
  end
end


Runner.run(Dialog)