anchor.diff:      end.
   
   twitter_at_url(Name) ->
  -    ["@<a href=\"http://twitter.com/", Name, "\">", Name, "</a>"].
  +    ["<a href=\"http://twitter.com/", Name, "\">@", Name, "</a>"].
   
   twitter1_hash(Input, Index, Context) ->
       case Input of
  -        <<Name:Index/binary, Char, Post/binary>> when not(Char >= $a andalso Char < $z+1
  +        <<Name:Index/binary, Char, Post/binary>> when not(Char >= $a andalso Char =< $z
                                                             orelse
  -                                                          Char >= $A andalso Char < $Z+1
  +                                                          Char >= $A andalso Char =< $Z
                                                             orelse
  -                                                          Char >= $0 andalso Char < $9+1
  +                                                          Char >= $0 andalso Char =< $9
                                                             orelse Char =:= $_ orelse Char =:= $.
                                                            ) ->
               Html = twitter_hash_url(Name),
  
positive.code: 
  twitter1_at(Input, Index, Context) ->
      case Input of
          <<Name:Index/binary, Char, Post/binary>> when not(Char >= $a andalso Char < $z+1
                                                            orelse
                                                            Char >= $A andalso Char < $Z+1
                                                            orelse
                                                            Char >= $0 andalso Char < $9+1
                                                            orelse Char =:= $_ orelse Char =:= $.
                                                           ) ->
              Html = twitter_at_url(Name),
  
negative.code: -export([twitter/2]).
  
  
  twitter(undefined, _Context) -> undefined;
  twitter(<<"<p>", _/binary>> = Input, _Context) -> Input;
  twitter(Input, Context) when is_binary(Input) -> twitter1(Input, 0, Context);
  twitter(Input, _Context) -> Input.
  
  twitter1(Input, Index, Context) when is_binary(Input) ->
      case Input of
  