package DFA;
sub new {
  my $dfa = {};
  bless $dfa, shift;   # associates $dfa with the current package
  $dfa->{buffer} = '';
  $dfa->{output} = []; # note: output is now an array reference
  $dfa->{states} = {}; # note: states is now a hash ref
  $dfa;                # return the new object
}
...