anchor.diff:  escape_uri([], Result) ->
       Result.
   
  +parse_host(undefined) ->
  +    undefined;
   parse_host(Host) ->
       case parse_host(Host, "") of
           {_, Host1, Port, _, _} -> {Host1, Port};
  
positive.code: parse_scheme([], _) ->
      undefined.
  
  parse_host(undefined, Scheme) ->
      parse_host("", Scheme);
  parse_host([$[ | Rest], Scheme) ->
      parse_host_rfc2732(Rest, "", Scheme);
  parse_host(String, Scheme) ->
  
negative.code: %% URI parsing.
  %% -------------------------------------------------------------------
  
  parse_uri([$/ | _] = String) ->
      parse_path(String, undefined, undefined, undefined);
  parse_uri(String) ->
      parse_scheme(String, "").
  
  