Copy fix changes!!!!

gistfile1.txt

For NFA.java:

  public NFA copy() {
    NFA copy = new NFA();
    Map<NFAState, NFAState> oldToNew = new HashMap<NFAState, NFAState>();
    List<NFAState> oldStates = getAllStates();

    //create a map linking all the old states to the new copies
    for (NFAState oState : oldStates) {
        NFAState nState = oState.copy();
        oldToNew.put(oState, nState);
    }

    //below is a modified dfs
    Set<NFAState> discovered = new HashSet<NFAState>();
    Stack<NFAState> nextStatesToExplore = new Stack<NFAState>();
    NFAState old, newState;

    nextStatesToExplore.push(start);

    //traverse the old nfa
    while(!nextStatesToExplore.empty()) {
        old = nextStatesToExplore.pop();
        newState = oldToNew.get(old);

        for(NFAState nextState : old.getNextStates()) {
            //add all the next new states based on the old next states
            newState.addNext(oldToNew.get(nextState));

            if((!nextStatesToExplore.contains(nextState))
                    && (!discovered.contains(nextState))) {
                nextStatesToExplore.push(nextState);
            }
        }
        discovered.add(old);
    }

    copy.setStartState(oldToNew.get(start));
    return copy;
  }

  public List<NFAState> getAllStates() {
    List<NFAState> allStates = new ArrayList<NFAState>();

    Set<NFAState> discovered = new HashSet<NFAState>();
    Stack<NFAState> nextStatesToExplore = new Stack<NFAState>();
    NFAState temp;

    nextStatesToExplore.push(start);

    while(!nextStatesToExplore.empty()) {
        temp = nextStatesToExplore.pop();
        allStates.add(temp);

        for(NFAState nextState : temp.getNextStates()) {
            if((!nextStatesToExplore.contains(nextState))
                    && (!discovered.contains(nextState))) {
                nextStatesToExplore.push(nextState);
            }
        }

        discovered.add(temp);
    }

    return allStates;
  }
    

For NFAState.java:

  public NFAState copy() {
    return NFAState.builder()
        .setAccept(accept)
        .setTransition(transition).build();
  }