/**
* Calculate the set of states that are accepting and have a true self loop.
*/
public void calculateAcceptingTrueLoops()
{
_accepting_true_loops = new BitSet();
//BitSet isAcceptingTrueLoop= *_accepting_true_loops;
BitSet isAcceptingTrueLoop = _accepting_true_loops;////////changed
SCCs sccs = getSCCs();
for (int scc = 0; scc < sccs.countSCCs(); ++scc)
{
if (sccs[scc].cardinality() == 1)
{
int state_id = sccs[scc].nextSetBit(0);
NBA_State state = _nba[state_id];
if (!state.isFinal())
{
// not final, consider next
continue;
}
if (!sccs.successors(scc).isEmpty())//////////note here
{
// there are edges leaving this state, consider next
continue;
}
bool no_empty_to = true;
if (sccs.stateIsReachable(state_id, state_id))
{
// state has at least one self-loop
// we have to check that there is no edge with empty To
//for (typename NBA_t::edge_iterator eit=state->edges_begin(); eit!=state->edges_end(); ++eit)
//BitSet[] edges = state._edge_manager._container._storage;
//foreach (BitSet eit in edges)
for (KeyValuePair <APElement, BitSet> eit = state.edges_begin(); !state.edges_end(); eit = state.increment())
{
BitSet edge = eit.Value;
if (edge.isEmpty())
{
// not all edges lead back to the state...
no_empty_to = false;
break;
}
}
if (no_empty_to)
{
// When we are here the state is a final true loop
isAcceptingTrueLoop.set(state_id);
// std::cerr << "True Loop: " << state_id << std::endl;
}
}
}
}
}
/**
* Remove states from the set of accepting (final) states when this is redundant.
* @param sccs the SCCs of the NBA
*/
public void removeRedundantFinalStates(SCCs sccs)
{
for (int scc = 0; scc < sccs.countSCCs(); ++scc)
{
if (sccs[scc].cardinality() == 1)
{
int state_id = sccs[scc].nextSetBit(0);
NBA_State state = this[state_id];
if (state.isFinal())
{
if (!sccs.stateIsReachable(state_id, state_id))
{
// The state is final and has no self-loop
// -> the final flag is redundant
state.setFinal(false);
// std::cerr << "Removing final flag for " << state_id << std::endl;
}
}
}
}
}
/**
* Calculates BitSet which specifies which states in the NBA
* only have accepting successors.
*/
public void calculateStatesWithAllSuccAccepting()
{
_allSuccAccepting = new BitSet();
BitSet result = _allSuccAccepting;
SCCs sccs = getSCCs();
List <bool> scc_all_final = new List <bool>();
Ultility.resize(scc_all_final, sccs.countSCCs());
for (int i = 0; i < scc_all_final.Count; i++)
{
scc_all_final[i] = false;
}
for (int i = sccs.countSCCs(); i > 0; --i)
{
// go backward in topological order...
int scc = (sccs.topologicalOrder())[i - 1];
BitSet states_in_scc = sccs[scc];
// check to see if all states in this SCC are final
scc_all_final[scc] = true;
//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))
{
if (!_nba[it].isFinal())
{
scc_all_final[scc] = false;
break;
}
}
bool might_be_final = false;
if (scc_all_final[scc] == false)
{
if (states_in_scc.length() == 1)
{
// there is only one state in this scc ...
int state = states_in_scc.nextSetBit(0);
if (sccs.stateIsReachable(state, state) == false)
{
// ... and it doesn't loop to itself
might_be_final = true;
}
}
}
if (scc_all_final[scc] == true || might_be_final)
{
// Check to see if all successors are final...
bool all_successors_are_final = true;
BitSet scc_succ = sccs.successors(scc);
//for (BitSetIterator it=BitSetIterator(scc_succ); it!=BitSetIterator::end(scc_succ); ++it) {
for (int it = BitSetIterator.start(scc_succ); it != BitSetIterator.end(scc_succ); it = BitSetIterator.increment(scc_succ, it))
{
if (!scc_all_final[it])
{
all_successors_are_final = false;
break;
}
}
if (all_successors_are_final)
{
// Add all states in this SCC to the result-set
result.Or(states_in_scc);
if (might_be_final)
{
scc_all_final[scc] = true;
}
}
}
}
}
/** 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);
}
/**
* Remove states from the set of accepting (final) states when this is redundant.
* @param sccs the SCCs of the NBA
*/
public void removeRedundantFinalStates(SCCs sccs)
{
for (int scc = 0; scc < sccs.countSCCs(); ++scc)
{
if (sccs[scc].cardinality() == 1)
{
int state_id = sccs[scc].nextSetBit(0);
NBA_State state = this[state_id];
if (state.isFinal())
{
if (!sccs.stateIsReachable(state_id, state_id))
{
// The state is final and has no self-loop
// -> the final flag is redundant
state.setFinal(false);
// std::cerr << "Removing final flag for " << state_id << std::endl;
}
}
}
}
}
/** Calculate the Directed Acyclical Graph (DAG) */
public void calculateDAG()
{
//_result._dag.Clear();
//_result._dag.resize(_result.countSCCs());
Ultility.resizeExact(_result._dag, _result.countSCCs());
//_result._reachability.resize(_result.countSCCs());
Ultility.resizeExact(_result._reachability, _result.countSCCs());
List <int> in_degree = new List <int>(_result.countSCCs());
Ultility.resizeExact(in_degree, _result.countSCCs());
for (int scc = 0; scc < _result.countSCCs(); ++scc)
{
_result._reachability[scc] = new BitSet();
_result._dag[scc] = new BitSet();
BitSet states_in_scc = _result[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 from_state = it;
if (_labelMark == null)
{
//for (typename SuccessorAccess::successor_iterator succ_it=_successor_access.begin(_graph, from_state);succ_it!=_successor_access.end(_graph, from_state); ++succ_it)
for (KeyValuePair <APElement, BitSet> it_set = _graph[from_state].edges_begin(); !_graph[from_state].edges_end(); it_set = _graph[from_state].increment())
{
for (int succ_it = BitSetIterator.start(it_set.Value); succ_it != BitSetIterator.end(it_set.Value); succ_it = BitSetIterator.increment(it_set.Value, succ_it))
{
int to_state = succ_it;
int to_scc = _result.state2scc(to_state);
if (to_scc != scc)
{
// Only successor in the DAG if not the same scc
if (!_result._dag[scc].get(to_scc))
{
// This SCC is a new successor, increment in_degree
in_degree[to_scc]++;
_result._dag[scc].set(to_scc);
}
}
// Reachability
_result._reachability[scc].set(to_scc);
}
}
}
else
{
BitSet it_set = _graph[from_state].getEdge(_labelMark);
//for (typename SuccessorAccess::successor_iterator succ_it=_successor_access.begin(_graph, from_state);succ_it!=_successor_access.end(_graph, from_state); ++succ_it)
for (int succ_it = BitSetIterator.start(it_set); succ_it != BitSetIterator.end(it_set); succ_it = BitSetIterator.increment(it_set, succ_it))
{
int to_state = succ_it;
int to_scc = _result.state2scc(to_state);
if (to_scc != scc)
{
// Only successor in the DAG if not the same scc
if (!_result._dag[scc].get(to_scc))
{
// This SCC is a new successor, increment in_degree
in_degree[to_scc]++;
_result._dag[scc].set(to_scc);
}
}
// Reachability
_result._reachability[scc].set(to_scc);
}
}
}
}
bool progress = true;
int cnt = 0;
//_result._topological_order.Clear();
//_result._topological_order.resize(_result.countSCCs());
Ultility.resizeExact(_result._topological_order, _result.countSCCs());
List <int> sort = new List <int>(_result.countSCCs());
Ultility.resizeExact(sort, _result.countSCCs());
while (progress)
{
progress = false;
for (int scc = 0; scc < _result.countSCCs(); ++scc)
{
if (in_degree[scc] == 0)
{
sort[scc] = cnt++;
progress = true;
in_degree[scc] = -1;
//for (BitSetIterator it_neighbors= BitSetIterator(_result._dag[scc]); it_neighbors!=BitSetIterator::end(_result._dag[scc]); ++it_neighbors)
for (int it_neighbors = BitSetIterator.start(_result._dag[scc]); it_neighbors != BitSetIterator.end(_result._dag[scc]); it_neighbors = BitSetIterator.increment(_result._dag[scc], it_neighbors))
{
int scc_to = it_neighbors;
in_degree[scc_to]--;
}
}
}
}
for (int i = 0; i < _result.countSCCs(); i++)
{
_result._topological_order[sort[i]] = i;
}
// traverse SCCs in reverse topological order
for (int i = _result.countSCCs(); i > 0; --i)
{
int cur_scc = _result._topological_order[i - 1];
BitSet reaches = _result._reachability[cur_scc];
//for (BitSetIterator it_neighbors= BitSetIterator(_result._dag[cur_scc]); it_neighbors!=BitSetIterator::end(_result._dag[cur_scc]);++it_neighbors) {
for (int it_neighbors = BitSetIterator.start(_result._dag[cur_scc]); it_neighbors != BitSetIterator.end(_result._dag[cur_scc]); it_neighbors = BitSetIterator.increment(_result._dag[cur_scc], it_neighbors))
{
int scc_to = it_neighbors;
reaches.Union(_result._reachability[scc_to]);
}
}
}
