anchor.diff:  %% the DNS limit on domain name labels.
   -spec decode(string()) -> string().
   decode(Input) ->
  +
     {Output, Input2} = case string:rstr(Input, [?DELIMITER]) of
                0 -> {"", Input};
                Pos ->
  
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: %% -*- coding: utf-8 -*-
  %% @doc Punycode ([RFC 3492](http://tools.ietf.org/html/rfc3492)) implementation.
  
  -module(punycode).
  