Modify the powerset algorithm to keep track of accepting states

from the initial automaton.

* src/tgba/tgbaexplicit.cc, src/tgba/tgbaexplicit.hh:
Added class tgba_explicit_number, a tgba_explicit where states are
labelled by integers.
* src/tgbaalgos/powerset.hh, src/tgbaalgos/powerset.cc:
When building the deterministic automaton, keep track of which states
were created from an accepting state in the initial automaton.
The states are added to the new optional parameter (if not 0),
acc_list.
Use tgba_explicit_number instead of tgba_explicit_string to build
the result.
* src/tgbaalgos/scc.cc (spot): Small fix.
Print everything on std::cout.

ChangeLog

@@ -1,3 +1,21 @@
+2010-03-20  Felix Abecassis  <abecassis@lrde.epita.fr>
+
+	Modify the powerset algorithm to keep track of accepting states
+	from the initial automaton.
+
+	* src/tgba/tgbaexplicit.cc, src/tgba/tgbaexplicit.hh:
+	Added tgba_explicit_number, a tgba_explicit where states are labelled
+	by integers.
+	* src/tgbaalgos/powerset.hh, src/tgbaalgos/powerset.cc:
+	When building the deterministic automaton, keep track of which states
+	were created from an accepting state in the initial automaton.
+	The states are added to the new optional parameter (if not 0),
+	acc_list.
+	Now use tgba_explicit_number instead of tgba_explicit_string to build
+	the result.
+	* src/tgbaalgos/scc.cc (spot): Small fix.
+	Print everything on std::cout.
+
 2011-01-05  Alexandre Duret-Lutz  <adl@lrde.epita.fr>
 
 	Fix computation of support_conditions for bdd-based TGBA.

src/tgba/tgbaexplicit.cc

@@ -21,6 +21,7 @@
 // Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 // 02111-1307, USA.
 
+#include <sstream>
 #include "ltlast/atomic_prop.hh"
 #include "ltlast/constant.hh"
 #include "tgbaexplicit.hh"
@@ -349,4 +350,34 @@ namespace spot
     return ltl::to_string(i->second);
   }
 
+  tgba_explicit_number::~tgba_explicit_number()
+  {
+    ns_map::iterator i = name_state_map_.begin();
+    while (i != name_state_map_.end())
+    {
+      tgba_explicit::state::iterator i2;
+      for (i2 = i->second->begin(); i2 != i->second->end(); ++i2)
+	delete *i2;
+      // Advance the iterator before deleting the formula.
+      delete i->second;
+      ++i;
+    }
+  }
+
+  tgba_explicit::state* tgba_explicit_number::add_default_init()
+  {
+    return add_state(0);
+  }
+
+  std::string
+  tgba_explicit_number::format_state(const spot::state* s) const
+  {
+    const state_explicit* se = dynamic_cast<const state_explicit*>(s);
+    assert(se);
+    sn_map::const_iterator i = state_name_map_.find(se->get_state());
+    assert(i != state_name_map_.end());
+    std::stringstream ss;
+    ss << i->second;
+    return ss.str();
+  }
 }

src/tgba/tgbaexplicit.hh

@@ -345,6 +345,18 @@ namespace spot
     virtual state* add_default_init();
     virtual std::string format_state(const spot::state* s) const;
   };
+
+  class tgba_explicit_number:
+    public tgba_explicit_labelled<int, std::tr1::hash<int> >
+  {
+  public:
+    tgba_explicit_number(bdd_dict* dict):
+      tgba_explicit_labelled<int, std::tr1::hash<int> >(dict)
+    {};
+    virtual ~tgba_explicit_number();
+    virtual state* add_default_init();
+    virtual std::string format_state(const spot::state* s) const;
+  };
 }
 
 #endif // SPOT_TGBA_TGBAEXPLICIT_HH

src/tgbaalgos/powerset.cc

@@ -24,25 +24,28 @@
 #include <set>
 #include <map>
 #include <deque>
-#include <sstream>
+#include "powerset.hh"
 #include "misc/hash.hh"
 #include "tgbaalgos/powerset.hh"
+#include "tgbaalgos/scc.hh"
 #include "bdd.h"
 
 namespace spot
 {
   tgba_explicit*
-  tgba_powerset(const tgba* aut)
+  tgba_powerset(const tgba* aut,
+                std::list<const state*>* acc_list)
   {
     typedef Sgi::hash_set<const state*, state_ptr_hash,
                           state_ptr_equal> state_set;
     typedef std::set<const state*, state_ptr_less_than> power_state;
-    typedef std::map<power_state, std::string> power_set;
+    typedef std::map<power_state, int> power_set;
     typedef std::deque<power_state> todo_list;
 
     power_set seen;
     todo_list todo;
-    tgba_explicit_string* res = new tgba_explicit_string(aut->get_dict());
+    scc_map m(aut);
+    tgba_explicit_number* res = new tgba_explicit_number(aut->get_dict());
 
     state_set states;
 
@@ -52,7 +55,8 @@ namespace spot
       states.insert(s);
       ps.insert(s);
       todo.push_back(ps);
-      seen[ps] = "1";
+      seen[ps] = 1;
+      m.build_map();
     }
 
     unsigned state_num = 1;
@@ -77,6 +81,7 @@ namespace spot
 
 	    // Construct the set of all states reachable via COND.
 	    power_state dest;
+            bool accepting = false;
 	    for (i = src.begin(); i != src.end(); ++i)
 	      {
 		tgba_succ_iterator *si = aut->succ_iter(*i);
@@ -94,30 +99,36 @@ namespace spot
 			{
 			  states.insert(s);
 			}
+                      unsigned scc_num = m.scc_of_state(s);
+                      if (m.accepting(scc_num))
+                        accepting = true;
 		      dest.insert(s);
 		    }
 		delete si;
 	      }
 	    if (dest.empty())
 	      continue;
-
 	    // Add that transition.
 	    power_set::const_iterator i = seen.find(dest);
-	    std::string dest_name;
+	    int dest_num;
+	    tgba_explicit::transition* t;
 	    if (i != seen.end())
 	      {
-		dest_name = i->second;
+		dest_num = i->second;
+                t = res->create_transition(seen[src], dest_num);
 	      }
 	    else
 	      {
-		std::ostringstream str;
+		dest_num = ++state_num;
-		str << ++state_num;
+		seen[dest] = dest_num;
-		dest_name = str.str();
-		seen[dest] = dest_name;
 		todo.push_back(dest);
+                t = res->create_transition(seen[src], dest_num);
+                if (acc_list && accepting)
+                {
+                  const state* dst = new state_explicit(t->dest);
+                  acc_list->push_front(dst);
+                }
 	      }
-	    tgba_explicit::transition* t =
-	      res->create_transition(seen[src], dest_name);
 	    res->add_conditions(t, cond);
 	  }
       }

src/tgbaalgos/powerset.hh

@@ -22,6 +22,7 @@
 #ifndef SPOT_TGBAALGOS_POWERSET_HH
 # define SPOT_TGBAALGOS_POWERSET_HH
 
+# include <list>
 # include "tgba/tgbaexplicit.hh"
 
 namespace spot
@@ -32,7 +33,11 @@ namespace spot
   /// This create a deterministic automaton that recognize the
   /// same language as \a aut would if its acceptance conditions
   /// were ignored.  This is the classical powerset algorithm.
-  tgba_explicit* tgba_powerset(const tgba* aut);
+  /// If acc_list is not 0. Whenever a power state is created from one
+  /// accepting state (a state belonging to an accepting SCC), then this power
+  /// state is added to acc_list.
+  tgba_explicit* tgba_powerset(const tgba* aut,
+                               std::list<const state*>* acc_list = 0);
 }
 
 #endif // SPOT_TGBAALGOS_POWERSET_HH

src/tgbaalgos/scc.cc

@@ -505,7 +505,7 @@ namespace spot
 					       m.useful_acc_of(state))) << "]";
 	  }
 
-	std::cout << "  " << state << " [shape=box,"
+	out << "  " << state << " [shape=box,"
             << (m.accepting(state) ? "style=bold," : "")
             << "label=\"" << ostr.str() << "\"]" << std::endl;