Add several options to CAR

* spot/twa/acc.hh: Remove useless comment.
* spot/twaalgos/car.cc: Rewrite the implementation to try
  multiple algorithms and choose the best, add the possibility
  to force the order of the colors/pairs in LAR and use
  propagate_marks_here.
* spot/twaalgos/car.hh, tests/python/car.py: Create a new system of
  options for CAR.
* spot/twaalgos/degen.cc, spot/twaalgos/degen.hh: Add the possibility
  to forbid some marks in is_partially_degeneralizable.

spot/twa/acc.hh

@@ -592,7 +592,6 @@ namespace spot
         }
         if (elements.size() == 2)
         {
-          // Vaut 1 si si c'est le 2e qui est bon
           unsigned pos = elements[1].back().sub.op == op
                         && elements[1][0].mark.count() == 1;
           if (!(elements[0].back().sub.op == op || pos))

spot/twaalgos/car.hh

@@ -23,6 +23,23 @@
 
 namespace spot
 {
+  struct car_option
+{
+    bool search_ex      = true;
+    bool use_last       = true;
+    bool force_order    = true;
+    bool partial_degen  = true;
+    bool acc_clean      = true;
+    bool parity_equiv   = true;
+    bool parity_prefix  = true;
+    bool rabin_to_buchi = true;
+    bool reduce_col_deg = false;
+    bool propagate_col  = true;
+    bool pretty_print   = true;
+};
+
+
+
 /// \ingroup twa_acc_transform
 /// \brief Take an automaton with any acceptance condition and return an
 /// equivalent parity automaton.
@@ -43,17 +60,10 @@ namespace spot
 /// If \a pretty_print is true, we give a name to the states describing the
 // state of the aut_ and the permutation.
 
-  SPOT_API twa_graph_ptr
-  remove_false_transitions(const twa_graph_ptr a);
+SPOT_API twa_graph_ptr
+remove_false_transitions(const twa_graph_ptr a);
+
+SPOT_API twa_graph_ptr
+to_parity(const twa_graph_ptr &aut, const car_option options = car_option());
 
-  SPOT_API twa_graph_ptr
-  car(const twa_graph_ptr &aut,
-    bool search_ex = true,
-    bool partial_degen = true,
-    bool scc_acc_clean = true,
-    bool parity_equiv = true,
-    bool use_last = true,
-    bool parity_prefix = true,
-    bool rabin_to_buchi = true,
-    bool pretty_print = false);
 } // namespace spot

spot/twaalgos/degen.cc

@@ -846,7 +846,8 @@ namespace spot
 
   acc_cond::mark_t
   is_partially_degeneralizable(const const_twa_graph_ptr& aut,
-                               bool allow_inf, bool allow_fin)
+                               bool allow_inf, bool allow_fin,
+                               std::vector<acc_cond::mark_t> forbid)
   {
     auto& code = aut->get_acceptance();
 
@@ -881,15 +882,21 @@ namespace spot
           case acc_cond::acc_op::FinNeg:
             pos -= 2;
             if (allow_fin)
-              if (update(code[pos].mark))
+            {
+              auto m = code[pos].mark;
+              if (!std::count(forbid.begin(), forbid.end(), m) && update(m))
                 return res;
+            }
             break;
           case acc_cond::acc_op::Inf:
           case acc_cond::acc_op::InfNeg:
             pos -= 2;
             if (allow_inf)
-              if (update(code[pos].mark))
+            {
+              auto m = code[pos].mark;
+              if (!std::count(forbid.begin(), forbid.end(), m) && update(m))
                 return res;
+            }
             break;
           }
       }

spot/twaalgos/degen.hh

@@ -151,7 +151,8 @@ namespace spot
   SPOT_API acc_cond::mark_t
   is_partially_degeneralizable(const const_twa_graph_ptr& aut,
                                bool allow_inf = true,
-                               bool allow_fin = true);
+                               bool allow_fin = true,
+                               std::vector<acc_cond::mark_t> forbid = {});
 
   /// \ingroup twa_algorithms
   /// \brief Propagate marks around the automaton