anchor.diff:      undefined.
   
   -spec chr(context(), line(), Integer :: var_value()) -> binary().
  -
  +%% @doc obtain the character giving the number as a param.
   chr(_Context, _Line, {_,C}) when is_integer(C) ->
       <<C:8/integer>>;
   
  
positive.code: 
  
  -spec strlen(context(), line(), String :: var_value()) -> integer().
  
  strlen(_Context, _Line, {_,String}) when is_binary(String) ->
      byte_size(String);
  
  
negative.code: 
  -spec implode(context(), line(),
      Glue :: var_value(), Pieces :: var_value()) -> binary().
  %% @doc join the array with the glue passed as a param.
  implode(Context, Line, {_,Glue}=VarGlue, _Pieces) when ?IS_ARRAY(Glue) ->
      File = ephp_context:get_active_file(Context),
      Error = {error, earrayconv, Line, File, ?E_NOTICE, {<<"string">>}},
  