anchor.diff: +%% -*- coding: utf-8 -*-
   %% @doc Punycode ([RFC 3492](http://tools.ietf.org/html/rfc3492)) implementation.
   
   -module(punycode).
  
positive.code:           exit(overflow)
        end
    end.
  
  digit(C) when C >= $0, C =< $9 -> C - $0 + 26;
  digit(C) when C >= $A, C =< $Z -> C - $A;
  
negative.code:            end,
    decode(Input2, Output, ?INITIAL_N, ?INITIAL_BIAS, 0).
  
  decode([], Output, _, _, _) -> Output;
  decode(Input, Output, N, Bias, I) ->
    decode(Input, Output, N, Bias, I, I, 1, ?BASE).
  
  decode([C|Rest], Output, N, Bias, I0, OldI, Weight, K) ->
    Digit = digit(C),
  