todo.exs

defmodule Todo do
  import String, only: [split: 3, trim: 1];
  @t :todos
  @d :dets
  def prompt() do IO.write("todo> "); split(trim(IO.binread(:line)), " ", parts: 2) end
  def run(:start) do @d.open_file(@t, type: :set); run(">")  end
  def run(:goodbye), do: @d.close(@t)
  def run(_) do
    case prompt() do
      [c] when c in ["", "ls"] -> @d.match_object(@t, {:"$1", false})
      ["ls", "done"] -> @d.match_object(@t, {:"$1", true})
      ["ls", "all"] -> @d.match_object(@t, {:"$1", :_})
      ["add", item] -> @d.insert(@t, {item, false})
      ["done", item] -> @d.insert(@t, {item, true})
      ["rm", item] -> @d.match_delete(@t, {item, :_})
      ["reset"] -> @d.delete_all_objects(@t)
      ["exit"] -> :goodbye
      c -> {:invalid_command, c}
    end
    |> IO.inspect(pretty: true) |> run()
  end
end
Todo.run(:start)