Elixir experiments

service.exs

defmodule Listener do
  def on(event, message)

  def on(:do_this, message) do
    IO.puts "Yes #{message}"
  end

  def on(:do_that, _message) do
    IO.puts "No, I'm ignoring the message"
  end
end

defmodule Service do
  def call(data, listener) do
    listener.(:do_this, data.this)
    listener.(:do_that, data.that)
  end
end

data = %{this: "awesome", that: "go away"}
callback = &Listener.on/2
Service.call data, callback