/** Check if the NBA is empty. * @return true iff the NBA has no accepting run. */ public bool emptinessCheck() { SCCs sccs = getSCCs(); #if VERBOSE std::cerr << sccs << "\n"; std::cerr << " Reachability: " << std::endl; std::vector <BitSet> *reachable = sccs.getReachabilityForAllStates(); for (unsigned int t = 0; t < reachable->size(); t++) { std::cerr << t << " -> " << (*reachable)[t] << std::endl; } delete reachable; #endif for (int scc = 0; scc < sccs.countSCCs(); ++scc) { BitSet states_in_scc = sccs[scc]; // check to see if there is an accepting state in this SCC //for (BitSetIterator it=BitSetIterator(states_in_scc); it!=BitSetIterator::end(states_in_scc); ++it) for (int it = BitSetIterator.start(states_in_scc); it != BitSetIterator.end(states_in_scc); it = BitSetIterator.increment(states_in_scc, it)) { int state = it; #if VERBOSE std::cerr << "Considering state " << state << std::endl; #endif if (_nba[state].isFinal()) { // check to see if this SCC is a trivial SCC (can't reach itself) #if VERBOSE std::cerr << " +final"; std::cerr << " " << states_in_scc.cardinality(); #endif if (states_in_scc.cardinality() == 1) { // there is only one state in this scc ... #if VERBOSE std::cerr << " +single"; #endif if (sccs.stateIsReachable(state, state) == false) { // ... and it doesn't loop to itself // -> can not guarantee accepting run #if VERBOSE std::cerr << " -no_loop" << std::endl; #endif continue; } } // if we are here, the SCC has more than 1 state or // exactly one self-looping state // -> accepting run #if VERBOSE std::cerr << "+acc" << std::endl; #endif // check that SCC can be reached from initial state Debug.Assert(_nba.getStartState() != null); if (sccs.stateIsReachable(_nba.getStartState().getName(), state)) { #if VERBOSE std::cerr << "Found accepting state = " << state << std::endl; #endif return(false); } #if VERBOSE std::cerr << "Not reachable!" << std::endl; #endif continue; } } } return(true); }
/** Calculate the stutter closure for the NBA, for all symbols. * @param nba the NBA */ public static NBA stutter_closure(NBA nba) { APSet apset = nba.getAPSet_cp(); NBA nba_result_ptr = new NBA(apset); NBA result = nba_result_ptr; int element_count = apset.powersetSize(); Debug.Assert(nba.getStartState() != null); int start_state = nba.getStartState().getName(); for (int i = 0; i < nba.size(); i++) { int st = result.nba_i_newState(); Debug.Assert(st == i); if (st == start_state) { result.setStartState(result[st]); } if (nba[st].isFinal()) { result[st].setFinal(true); } } for (int i = 0; i < nba.size(); i++) { for (int j = 0; j < element_count; j++) { int st = result.nba_i_newState(); Debug.Assert(st == nba.size() + (i*element_count) + j); result[st].addEdge(new APElement(j), result[i]); result[st].addEdge(new APElement(j), result[st]); } } List<List<BitSet>> reachable = new List<List<BitSet>>(); //reachable.resize(element_count); Ultility.resize(reachable, element_count); for (int j = 0; j < element_count; j++) { //NBAEdgeSuccessors edge_successor = new NBAEdgeSuccessors(new APElement(j)); SCCs scc = new SCCs(); GraphAlgorithms.calculateSCCs(nba, scc, true, new APElement(j)); //,edge_successor reachable[j] = scc.getReachabilityForAllStates(); #if VERBOSE std::cerr << "SCCs for " << APElement(j).toString(*apset) << std::endl; std::cerr << scc << std::endl; std::cerr << " Reachability: "<< std::endl; std::vector<BitSet>& reach=*reachable[j]; for (unsigned int t=0; t < reach.size(); t++) { std::cerr << t << " -> " << reach[t] << std::endl; } std::cerr << " ---\n"; #endif } for (int i = 0; i < nba.size(); i++) { NBA_State from = result[i]; for (int j = 0; j < element_count; j++) { BitSet result_to = new BitSet(); BitSet to = nba[i].getEdge(new APElement(j)); //for (BitSetIterator it=BitSetIterator(*to);it!=BitSetIterator::end(*to);++it) for (int it = BitSetIterator.start(to); it != BitSetIterator.end(to); it = BitSetIterator.increment(to, it)) { int to_state = it; // We can go directly to the original state result_to.set(to_state); // We can also go to the corresponding stutter state instead int stutter_state = nba.size() + (to_state*element_count) + j; result_to.set(stutter_state); // ... and then we can go directly to all the states that are j-reachable from to result_to.Union(reachable[j][to_state]); } from.getEdge(new APElement(j)).Assign(result_to); } } //for (int i=0; i<reachable.size(); ++i) { // delete reachable[i]; // } return nba_result_ptr; }
/** Calculate the stutter closure for the NBA, for a certain symbol. * @param nba the NBA * @param label the symbol for which to perform the stutter closure */ public static NBA stutter_closure(NBA nba, APElement label) { APSet apset = nba.getAPSet_cp(); NBA nba_result_ptr = new NBA(apset); NBA result = nba_result_ptr; int element_count = apset.powersetSize(); Debug.Assert(nba.getStartState() != null); int start_state = nba.getStartState().getName(); for (int i = 0; i < nba.size(); i++) { int st = result.nba_i_newState(); Debug.Assert(st == i); if (st == start_state) { result.setStartState(result[st]); } if (nba[st].isFinal()) { result[st].setFinal(true); } } for (int i = 0; i < nba.size(); i++) { int st = result.nba_i_newState(); Debug.Assert(st == nba.size() + i); result[st].addEdge(label, result[i]); result[st].addEdge(label, result[st]); } //List<BitSet> reachable = null; //NBAEdgeSuccessors edge_successor = new NBAEdgeSuccessors(label); SCCs scc = new SCCs(); GraphAlgorithms.calculateSCCs(nba, scc, true, label); //,edge_successor List <BitSet> reachable = scc.getReachabilityForAllStates(); // std::cerr << "SCCs for " << label.toString(*apset) << std::endl; // std::cerr << scc << std::endl; // std::cerr << " Reachability: "<< std::endl; // for (unsigned int t=0; t < reachable->size(); t++) { // std::cerr << t << " -> " << (*reachable)[t] << std::endl; // } // std::cerr << " ---\n"; for (int i = 0; i < nba.size(); i++) { NBA_State from = result[i]; for (int j = 0; j < element_count; j++) { BitSet result_to = new BitSet(); BitSet to = nba[i].getEdge(new APElement(j)); if (j != label.bitset) { result_to = to; } else { //for (BitSetIterator it=BitSetIterator(*to);it!=BitSetIterator::end(*to);++it) for (int it = BitSetIterator.start(to); it != BitSetIterator.end(to); it = BitSetIterator.increment(to, it)) { int to_state = it; // We can go directly to the original state result_to.set(to_state); // We can also go to the corresponding stutter state instead int stutter_state = nba.size() + to_state; result_to.set(stutter_state); // ... and then we can go directly to all the states that are j-reachable from to result_to.Union(reachable[to_state]); } } from.getEdge(new APElement(j)).Assign(result_to); } } //delete reachable; return(nba_result_ptr); }
/** Calculate the stutter closure for the NBA, for a certain symbol. * @param nba the NBA * @param label the symbol for which to perform the stutter closure */ public static NBA stutter_closure(NBA nba, APElement label) { APSet apset = nba.getAPSet_cp(); NBA nba_result_ptr = new NBA(apset); NBA result = nba_result_ptr; int element_count = apset.powersetSize(); Debug.Assert(nba.getStartState() != null); int start_state = nba.getStartState().getName(); for (int i = 0; i < nba.size(); i++) { int st = result.nba_i_newState(); Debug.Assert(st == i); if (st == start_state) { result.setStartState(result[st]); } if (nba[st].isFinal()) { result[st].setFinal(true); } } for (int i = 0; i < nba.size(); i++) { int st = result.nba_i_newState(); Debug.Assert(st == nba.size() + i); result[st].addEdge(label, result[i]); result[st].addEdge(label, result[st]); } //List<BitSet> reachable = null; //NBAEdgeSuccessors edge_successor = new NBAEdgeSuccessors(label); SCCs scc = new SCCs(); GraphAlgorithms.calculateSCCs(nba, scc, true, label); //,edge_successor List<BitSet> reachable = scc.getReachabilityForAllStates(); // std::cerr << "SCCs for " << label.toString(*apset) << std::endl; // std::cerr << scc << std::endl; // std::cerr << " Reachability: "<< std::endl; // for (unsigned int t=0; t < reachable->size(); t++) { // std::cerr << t << " -> " << (*reachable)[t] << std::endl; // } // std::cerr << " ---\n"; for (int i = 0; i < nba.size(); i++) { NBA_State from = result[i]; for (int j = 0; j < element_count; j++) { BitSet result_to = new BitSet(); BitSet to = nba[i].getEdge(new APElement(j)); if (j != label.bitset) { result_to = to; } else { //for (BitSetIterator it=BitSetIterator(*to);it!=BitSetIterator::end(*to);++it) for (int it = BitSetIterator.start(to); it != BitSetIterator.end(to); it = BitSetIterator.increment(to, it)) { int to_state = it; // We can go directly to the original state result_to.set(to_state); // We can also go to the corresponding stutter state instead int stutter_state = nba.size() + to_state; result_to.set(stutter_state); // ... and then we can go directly to all the states that are j-reachable from to result_to.Union(reachable[to_state]); } } from.getEdge(new APElement(j)).Assign(result_to); } } //delete reachable; return nba_result_ptr; }
/** Calculate the stutter closure for the NBA, for all symbols. * @param nba the NBA */ public static NBA stutter_closure(NBA nba) { APSet apset = nba.getAPSet_cp(); NBA nba_result_ptr = new NBA(apset); NBA result = nba_result_ptr; int element_count = apset.powersetSize(); Debug.Assert(nba.getStartState() != null); int start_state = nba.getStartState().getName(); for (int i = 0; i < nba.size(); i++) { int st = result.nba_i_newState(); Debug.Assert(st == i); if (st == start_state) { result.setStartState(result[st]); } if (nba[st].isFinal()) { result[st].setFinal(true); } } for (int i = 0; i < nba.size(); i++) { for (int j = 0; j < element_count; j++) { int st = result.nba_i_newState(); Debug.Assert(st == nba.size() + (i * element_count) + j); result[st].addEdge(new APElement(j), result[i]); result[st].addEdge(new APElement(j), result[st]); } } List <List <BitSet> > reachable = new List <List <BitSet> >(); //reachable.resize(element_count); Ultility.resize(reachable, element_count); for (int j = 0; j < element_count; j++) { //NBAEdgeSuccessors edge_successor = new NBAEdgeSuccessors(new APElement(j)); SCCs scc = new SCCs(); GraphAlgorithms.calculateSCCs(nba, scc, true, new APElement(j)); //,edge_successor reachable[j] = scc.getReachabilityForAllStates(); #if VERBOSE std::cerr << "SCCs for " << APElement(j).toString(*apset) << std::endl; std::cerr << scc << std::endl; std::cerr << " Reachability: " << std::endl; std::vector <BitSet>& reach = *reachable[j]; for (unsigned int t = 0; t < reach.size(); t++) { std::cerr << t << " -> " << reach[t] << std::endl; } std::cerr << " ---\n"; #endif } for (int i = 0; i < nba.size(); i++) { NBA_State from = result[i]; for (int j = 0; j < element_count; j++) { BitSet result_to = new BitSet(); BitSet to = nba[i].getEdge(new APElement(j)); //for (BitSetIterator it=BitSetIterator(*to);it!=BitSetIterator::end(*to);++it) for (int it = BitSetIterator.start(to); it != BitSetIterator.end(to); it = BitSetIterator.increment(to, it)) { int to_state = it; // We can go directly to the original state result_to.set(to_state); // We can also go to the corresponding stutter state instead int stutter_state = nba.size() + (to_state * element_count) + j; result_to.set(stutter_state); // ... and then we can go directly to all the states that are j-reachable from to result_to.Union(reachable[j][to_state]); } from.getEdge(new APElement(j)).Assign(result_to); } } //for (int i=0; i<reachable.size(); ++i) { // delete reachable[i]; // } return(nba_result_ptr); }