class Kleene::NFA

def deep_clone
  old_states = @states.to_a
  new_states = old_states.map(&:dup)
  state_mapping = old_states.zip(new_states).to_h
  new_transitions = transitions.map {|state, char_transition_map|
    [
      state_mapping[state],
      char_transition_map.map {|char, set_of_transisions|
        [
          char,
          set_of_transisions.map {|transition| NFATransition.new(transition.token, state_mapping[transition.from], state_mapping[transition.to])}.to_set
        ]
      }.to_h
    ]
  }.to_h
  NFA.new(state_mapping[@start_state], @alphabet.clone, new_transitions, new_states.to_set).set_regex_pattern(regex_pattern)
end