Esos Locos Bajitos (by Joan Manuel Serrat)

crazy_shorties.erl

-module crazy_shorties.
-author(joan_manuel).

-export [new/0, teach/1, direct/1].

new() ->
  Child = spawn_link(fun live/0),
  timer:send_interval(1000, Child, tick),
  Child.

live() ->
  live(#{direction => undefined, carried_stuff => [], age_in_seconds => 0}).

live(State) ->
  NewState =
    receive
      {compare, Parent} ->
        ParentInfo = erlang:process_info(Parent),
        ChildInfo = erlang:process_info(self()),
        Similarities = ParentInfo -- ChildInfo,
        Parent ! {satisfied, Similarities},
        State;
      {gesture, Gesture, Context} ->
        Stuff = context:get_nearby(Context),
        child:shake_with(Gesture, Stuff),
        State;
      {stand_up, _Time, _Traditions} ->
        child:open_eyes(full_width),
        child:stand_up(),
        State;

      {shout, Stuff} ->
        child:learn(Stuff),
        State;

      {god, God} ->
        State#{carried_stuff := [God | maps:get(carried_stuff, State)]};
      {learn, Word} ->
        State#{carried_stuff := [Word | maps:get(carried_stuff, State)]};
      {grudge, Grudge} ->
        State#{carried_stuff := [Grudge | maps:get(carried_stuff, State)]};
      {future, Future} ->
        State#{carried_stuff := [Future | maps:get(carried_stuff, State)]};
      {tale, Tale} ->
        child:listen_to(Tale),
        timer:sleep(1000),
        State;

      {go, Direction} ->
        State#{direction := Direction};
      {drink, Milk, Context} ->
        child:drink(Milk),
        Frustrations = context:get_frustrations(Context),
        State#{carried_stuff := [Frustrations | maps:get(carried_stuff, State)]};
      {listen, Song, Context} ->
        child:listen_to(Song),
        Frustrations = context:get_frustrations(Context),
        State#{carried_stuff := [Frustrations | maps:get(carried_stuff, State)]};

      tick ->
        try
          State#{
            direction := child:choose_direction(),
            age_in_seconds := maps:get(age_in_seconds, State) + 1
          }
        catch
          _:Error ->
            State#{
              carried_stuff := [Error | maps:get(carried_stuff, State)],
              age_in_seconds := maps:get(age_in_seconds, State) + 1
            }
        end

    end,
  case child:is_adult(State) of
    true ->
      {links, [ParentPid]} = erlang:process_info(self(), links),
      ParentPid ! good_bye,
      unlink(ParentPid),
      adult:live(State);
    false ->
      live(NewState)
  end.

teach(Child) ->
  Child ! {shout, "quit pestering with the ball!"},
  Child ! {shout, "don't say that!"},
  Child ! {shout, "don't do that!"},
  Child ! {shout, "don't touch that!"}.

direct(Child) ->
  Child ! {go, lists:nth(rand:uniform(4), [up, down, left, right])}.