anchor.diff:  %%% handled in some other place.
   %%%
   %%% Among other things process state contains:
  -%%% - current set of room with their descriptions
  +%%% - current set of rooms with their descriptions
   %%% - information about connectivity between rooms
   %%% - set of commands currently available to user
   %%%
  
positive.code: %% Very simple console user UI. 
  -export([console_play/0]).
  
  %% This is external exports for hot-reloading of console user UI.
  -export([console_play/1]).
  
  %% We are storing our gen_server state in map.
  
negative.code: %%% erl -eval 'compile:file(text_adv_game)' -eval 'text_adv_game:console_play()' -eval 'init:stop()' -noinput
  %%% '''
  %%%
  %%% @end
  %%%-------------------------------------------------------------------
  -module(text_adv_game).
  
  -behaviour(gen_server).
  
  %% Public API
  -export([start_link/0, command/3]).
  
  %% gen_server callbacks
  