TodoServer

register.ex

Process.register(self, :some_name)
send(:some_name, :msg)
receive do
  msg -> IO.puts "received #{msg}"
end

todo_server.ex

defmodule TodoServer do
  def start do
    spawn(fn -> loop(TodoList.new) end)
  end
  
  def add_entry(todo_server, new_entry) do
    send(todo_server, {:add_entry, new_entry})
  end
  
  defp process_message(todo_list, {:add_entry, new_entry}) do
    TodoList.add_entry(todo_list, new_entry)
  end
  
  def entries(todo_server, date) do
    send(todo_server, {:entries, self, date})
    
    receive do
      {:todo_entries, entries} -> entires
    after 5000 ->
      {:error, :timeout}
    end
  end
  
  defp process_message(todo_list, {:entries, caller, date}) do
    send(caller, {:todo_entries, TodoList.entries(todo_list, date)})
    todo_list
  end
  
  defp loop(todo_list) do
    new_todo_list = receive do
      message ->
        process_message(todo_list, message)
    end
    
    loop(new_todo_list)
  end
  
end