brain.ex

defmodule Edgar.Brain do
  def start_link do
    Agent.start_link(fn -> Map.new end, name: __MODULE__)
  end

  @doc "memorize something"
  def memorize(key, info) do
    Agent.update(__MODULE__, &Map.put(&1, key, info))
  end

  @doc "remember"
  def remember(key) do
    Agent.get(__MODULE__, &Map.get(&1, key))
  end

  @doc "forget"
  def forget(key) do
    Agent.update(__MODULE__, &Map.pop(&1, key))
  end
end

NotNot.ex

defmodule Edgar.Responder.NotNot do

  @moduledoc """
  resays what has been said
  """

  use Hedwig.Responder

  @usage """
  <text> (!!) - resays what has been said
  """

  respond ~r/(.*)/i, msg do
    case msg.matches[1] do
      "!!" -> ""
      _ ->
        Edgar.Brain.memorize(:lastmsg, msg.matches[1])
    end

  end

  respond ~r/!!/i, msg do
    send msg, Edgar.Brain.remember(:lastmsg)
  end
end