anchor.diff:  print1_string1([C|Cs], Q) ->
       string_char(C, Q, print1_string1(Cs, Q)).
   
  -string_char(Q, Q, Tail) -> [$\\,Q|Tail];    %Must check these first!
  +string_char(Q, Q, Tail) -> [$\\,Q|Tail];        %Must check these first!
   string_char($\\, _, Tail) -> [$\\,$\\|Tail];
   string_char(C, _, Tail) when C >= $\s, C =< $~ ->
       [C|Tail];
   string_char(C, _, Tail) when C >= $\240, C =< $\377 ->
       [C|Tail];
  -string_char($\n, _, Tail) -> [$\\,$n|Tail];    %\n = LF
  -string_char($\r, _, Tail) -> [$\\,$r|Tail];    %\r = CR
  -string_char($\t, _, Tail) -> [$\\,$t|Tail];    %\t = TAB
  -string_char($\v, _, Tail) -> [$\\,$v|Tail];    %\v = VT
  -string_char($\b, _, Tail) -> [$\\,$b|Tail];    %\b = BS
  -string_char($\f, _, Tail) -> [$\\,$f|Tail];    %\f = FF
  -string_char($\e, _, Tail) -> [$\\,$e|Tail];    %\e = ESC
  -string_char($\d, _, Tail) -> [$\\,$d|Tail];    %\d = DEL
  -string_char(C, _, Tail) ->            %Other control characters.
  -    C1 = hex(C bsr 4),
  -    C2 = hex(C band 15),
  -    [$\\,$x,C1,C2,$;|Tail].
  -
  -hex(C) when C >= 0, C < 10 -> C + $0;
  -hex(C) when C >= 10, C < 16 -> C + $a.
  +string_char($\n, _, Tail) -> [$\\,$n|Tail];     %\n = LF
  +string_char($\r, _, Tail) -> [$\\,$r|Tail];     %\r = CR
  +string_char($\t, _, Tail) -> [$\\,$t|Tail];     %\t = TAB
  +string_char($\v, _, Tail) -> [$\\,$v|Tail];     %\v = VT
  +string_char($\b, _, Tail) -> [$\\,$b|Tail];     %\b = BS
  +string_char($\f, _, Tail) -> [$\\,$f|Tail];     %\f = FF
  +string_char($\e, _, Tail) -> [$\\,$e|Tail];     %\e = ESC
  +string_char($\d, _, Tail) -> [$\\,$d|Tail];     %\d = DEL
  +string_char(C, _, Tail) ->
  +    %%Unicode and other control characters.
  +    "\\x" ++ erlang:integer_to_list(C, 16) ++ ";" ++ Tail.
   
   %% prettyprint([IoDevice], Sexpr) -> ok.
   %% prettyprint1(Sexpr, Depth, Indentation, LineLength) -> [char()].
  
positive.code: 
  start_symb_char($#) -> false;
  start_symb_char($`) -> false;
  start_symb_char($') -> false;            %'
  start_symb_char($,) -> false;
  start_symb_char($|) -> false;            %Symbol quote character
  start_symb_char(C) -> symb_char(C).
  
  symb_char($() -> false;
  
negative.code: 
  fwrite1(F, As) ->
      case catch lfe_io_format:fwrite1(F, As) of
          {'EXIT',_} ->                           %Something went wrong
              erlang:error(badarg, [F,As]);       %Signal from here
          Result -> Result
      end.
  