Examples with Transition dk.brics.automaton.Transition used on opensource projects

Example 1 with Transition

use of dk.brics.automaton.Transition in project evosuite by EvoSuite.

the class RegexDistanceUtils method cacheRegex.

private static void cacheRegex(String regex) {
    String r = expandRegex(regex);
    Automaton automaton = new RegExp(r, RegExp.NONE).toAutomaton();
    automaton.expandSingleton();
    // We convert this to a graph without self-loops in order to determine the topological order
    DirectedGraph<State, DefaultEdge> regexGraph = new DefaultDirectedGraph<State, DefaultEdge>(DefaultEdge.class);
    Set<State> visitedStates = new HashSet<State>();
    Queue<State> states = new LinkedList<State>();
    State initialState = automaton.getInitialState();
    states.add(initialState);
    while (!states.isEmpty()) {
        State currentState = states.poll();
        if (visitedStates.contains(currentState))
            continue;
        if (!regexGraph.containsVertex(currentState))
            regexGraph.addVertex(currentState);
        for (Transition t : currentState.getTransitions()) {
            // Need to get rid of back edges, otherwise there is no topological order!
            if (!t.getDest().equals(currentState)) {
                regexGraph.addVertex(t.getDest());
                regexGraph.addEdge(currentState, t.getDest());
                states.add(t.getDest());
                CycleDetector<State, DefaultEdge> det = new CycleDetector<State, DefaultEdge>(regexGraph);
                if (det.detectCycles()) {
                    regexGraph.removeEdge(currentState, t.getDest());
                }
            }
        }
        visitedStates.add(currentState);
    }
    TopologicalOrderIterator<State, DefaultEdge> iterator = new TopologicalOrderIterator<State, DefaultEdge>(regexGraph);
    List<State> topologicalOrder = new ArrayList<State>();
    while (iterator.hasNext()) {
        topologicalOrder.add(iterator.next());
    }
    regexStateCache.put(regex, topologicalOrder);
    regexAutomatonCache.put(regex, automaton);
}