/** 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);
}
