anchor.diff: +%% @doc The libspotify Erlang Interface. 
  +%%
  +%% <h3>Callback messages</h3> Many calls will at some point in time an
  +%% asynchronous callback message. For this purpose, the start/3
  +%% function has a pid() argument, and a set_pid/1 function is provided
  +%% to later change the callback pid.
  +%%
  +%% Callback messages are tagged tuples of the form
  +%% <pre>{'$spotify_callback', CallbackName::atom(), term()}</pre>,
  +%% where CallbackName is an atom named after the C function that
  +%% triggered the message; and term is a result term.
  +%%
  +%% @author Arjan Scherpenisse
   -module(espotify_nif).
   
   -export([
  
positive.code: stop() ->
      ?NOT_LOADED.
      
  set_pid(_) ->
      ?NOT_LOADED.
  
  player_load(_Track) ->
      ?NOT_LOADED.
  
  player_prefetch(_Track) ->
      ?NOT_LOADED.
  
  player_play(_Play) ->
      ?NOT_LOADED.
  
  player_seek(_Offset) ->
      ?NOT_LOADED.
  
  player_unload() ->
      ?NOT_LOADED.
  
negative.code:              end,
      ok = erlang:load_nif(SoName, 0).
  
  %% @doc Login to Spotify and start the main event loop. Only one
  %% Spotify session per VM is supported; this is a limitation of
  %% libspotify. The pid given will receive callback messages.
  %%
  %% On successful login, a message <pre>{'$spotify_callback', logged_in, {ok, #sp_user{}}} </pre> will be sent back.
  -spec start(string(), string(), pid()) -> ok | {error, already_started}.
  start(_, _, _) ->
      ?NOT_LOADED.
  