anchor.diff:      byte_size(Text).
   
   -spec sprintf(context(), line(), [var_value()]) -> binary().
  -
  +%% @doc generate a string using a format.
   sprintf(Context, Line, Values) when length(Values) < 2 ->
       File = ephp_context:get_active_file(Context),
       Error = {error, efewargs, Line, File, ?E_WARNING, {<<"sprintf">>}},
  
positive.code: ].
  
  -spec init_config() -> ephp_func:php_config_results().
  
  init_config() -> [].
  
  -spec init_const() -> ephp_func:php_const_results().
  
  init_const() -> [].
  
  -spec handle_error(ephp_error:error_type(), ephp_error:error_level(),
                     Args::term()) -> string() | ignore.
  
  handle_error(ehexeven, _Level, {Function}) ->
      io_lib:format("~s(): Hexadecimal input string must have an even length",
                    [Function]);
  
negative.code: 
  
  -spec strlen(context(), line(), String :: var_value()) -> integer().
  %% @doc retrieve the lenght of the string.
  strlen(_Context, _Line, {_,String}) when is_binary(String) ->
      byte_size(String);
  
  