tgba_succ_iterator: have first() and next() return a bool

The returned Boolean indicates whether there is a successor or not.
This way

|  for (i->first(); !i->done(); i->next())
|    {
|       ...
|    }

can be replaced by

| if (i->first()) do
|   {
|      ...
|   }
| while (i->next());

avoiding all the virtual calls to done().

* iface/dve2/dve2.cc, src/kripke/kripkeexplicit.cc,
src/kripke/kripkeexplicit.hh, src/ta/ta.hh, src/ta/taexplicit.cc,
src/ta/taexplicit.hh, src/ta/taproduct.cc, src/ta/taproduct.hh,
src/ta/tgtaproduct.cc, src/ta/tgtaproduct.hh, src/tgba/succiter.hh,
src/tgba/succiterconcrete.cc, src/tgba/succiterconcrete.hh,
src/tgba/taatgba.cc, src/tgba/taatgba.hh, src/tgba/tgba.hh,
src/tgba/tgbaexplicit.hh, src/tgba/tgbakvcomplement.cc,
src/tgba/tgbamask.cc, src/tgba/tgbaproduct.cc,
src/tgba/tgbasafracomplement.cc, src/tgba/tgbasgba.cc,
src/tgba/tgbatba.cc, src/tgba/tgbaunion.cc, src/tgba/tgbaunion.hh,
src/tgba/wdbacomp.cc: Implement and adjust to this new interface.

src/ta/ta.hh

@@ -1,5 +1,5 @@
 // -*- coding: utf-8 -*-
-// Copyright (C) 2010, 2012, 2013 Laboratoire de Recherche et
+// Copyright (C) 2010, 2012, 2013, 2014 Laboratoire de Recherche et
 // Developpement de l Epita (LRDE).
 //
 // This file is part of Spot, a model checking library.
@@ -191,12 +191,9 @@ namespace spot
     {
     }
 
-    virtual void
-    first() = 0;
-    virtual void
-    next() = 0;
-    virtual bool
-    done() const = 0;
+    virtual bool first() = 0;
+    virtual bool next() = 0;
+    virtual bool done() const = 0;
 
     virtual state*
     current_state() const = 0;

src/ta/taexplicit.cc

@@ -1,6 +1,6 @@
 // -*- coding: utf-8 -*-
-// Copyright (C) 2010, 2011, 2012, 2013 Laboratoire de Recherche et
-// Développement de l'Epita (LRDE).
+// Copyright (C) 2010, 2011, 2012, 2013, 2014 Laboratoire de Recherche
+// et Développement de l'Epita (LRDE).
 //
 // This file is part of Spot, a model checking library.
 //
@@ -54,24 +54,26 @@ namespace spot
     transitions_ = s->get_transitions(condition);
   }
 
-  void
+  bool
   ta_explicit_succ_iterator::first()
   {
-    if (transitions_ != 0)
-      i_ = transitions_->begin();
+    if (!transitions_)
+      return false;
+    i_ = transitions_->begin();
+    return i_ != transitions_->end();
   }
 
-  void
+  bool
   ta_explicit_succ_iterator::next()
   {
     ++i_;
+    return i_ != transitions_->end();
   }
 
   bool
   ta_explicit_succ_iterator::done() const
   {
-    return transitions_ == 0 || transitions_->empty() || i_
-        == transitions_->end();
+    return !transitions_ || i_ == transitions_->end();
   }
 
   state*

src/ta/taexplicit.hh

@@ -1,6 +1,6 @@
 // -*- coding: utf-8 -*-
-// Copyright (C) 2010, 2011, 2012, 2013 Laboratoire de Recherche et
-// Développement de l'Epita (LRDE).
+// Copyright (C) 2010, 2011, 2012, 2013, 2014 Laboratoire de Recherche
+// et Développement de l'Epita (LRDE).
 //
 // This file is part of Spot, a model checking library.
 //
@@ -248,12 +248,9 @@ namespace spot
 
     ta_explicit_succ_iterator(const state_ta_explicit* s, bdd condition);
 
-    virtual void
-    first();
-    virtual void
-    next();
-    virtual bool
-    done() const;
+    virtual bool first();
+    virtual bool next();
+    virtual bool done() const;
 
     virtual state*
     current_state() const;

src/ta/taproduct.cc

@@ -1,5 +1,5 @@
 // -*- coding: utf-8 -*-
-// Copyright (C) 2011, 2012 Laboratoire de Recherche et Développement
+// Copyright (C) 2011, 2012, 2014 Laboratoire de Recherche et Développement
 // de l'Epita (LRDE).
 //
 //
@@ -150,17 +150,18 @@ namespace spot
 
   }
 
-  void
+  bool
   ta_succ_iterator_product::first()
   {
 
     next_kripke_dest();
 
     if (!done())
-      next_non_stuttering_();
+      return next_non_stuttering_();
+    return false;
   }
 
-  void
+  bool
   ta_succ_iterator_product::next()
   {
     delete current_state_;
@@ -173,11 +174,11 @@ namespace spot
       step_();
 
     if (!done())
-      next_non_stuttering_();
-
+      return next_non_stuttering_();
+    return false;
   }
 
-  void
+  bool
   ta_succ_iterator_product::next_non_stuttering_()
   {
 
@@ -190,7 +191,7 @@ namespace spot
             current_state_ = new state_ta_product(source_->get_ta_state(),
                 kripke_current_dest_state->clone());
             current_acceptance_conditions_ = bddfalse;
-            return;
+            return true;
           }
 
         if (!ta_succ_it_->done())
@@ -199,11 +200,12 @@ namespace spot
                 kripke_current_dest_state->clone());
             current_acceptance_conditions_
                 = ta_succ_it_->current_acceptance_conditions();
-            return;
+            return true;
           }
 
         step_();
       }
+    return false;
   }
 
   bool

src/ta/taproduct.hh

@@ -1,5 +1,5 @@
 // -*- coding: utf-8 -*-
-// Copyright (C) 2011, 2012, 2013 Laboratoire de Recherche et
+// Copyright (C) 2011, 2012, 2013, 2014 Laboratoire de Recherche et
 // Développement de l'Epita (LRDE).
 //
 // This file is part of Spot, a model checking library.
@@ -83,12 +83,9 @@ namespace spot
     ~ta_succ_iterator_product();
 
     // iteration
-    void
-    first();
-    void
-    next();
-    bool
-    done() const;
+    bool first();
+    bool next();
+    bool done() const;
 
     // inspection
     state_ta_product*
@@ -106,10 +103,8 @@ namespace spot
   protected:
     //@{
     /// Internal routines to advance to the next successor.
-    void
-    step_();
-    void
-    next_non_stuttering_();
+    void step_();
+    bool next_non_stuttering_();
 
     /// \brief Move to the next successor in the kripke structure
     void

src/ta/tgtaproduct.cc

@@ -1,5 +1,5 @@
 // -*- coding: utf-8 -*-
-// Copyright (C) 2012 Laboratoire de Recherche et Developpement
+// Copyright (C) 2012, 2014 Laboratoire de Recherche et Développement
 // de l Epita (LRDE).
 //
 // This file is part of Spot, a model checking library.
@@ -173,19 +173,16 @@ namespace spot
 
   }
 
-  void
+  bool
   tgta_succ_iterator_product::first()
   {
 
     next_kripke_dest();
-    trace
-      << "*** first() .... if(done()) = ***" << done() << std::endl;
-    if (!done())
-      find_next_succ_();
-
+    trace << "*** first() .... if(done()) = ***" << done() << std::endl;
+    return find_next_succ_();
   }
 
-  void
+  bool
   tgta_succ_iterator_product::next()
   {
     current_state_->destroy();
@@ -193,18 +190,14 @@ namespace spot
 
     step_();
 
-    trace
-      << "*** next() .... if(done()) = ***" << done() << std::endl;
-
-    if (!done())
-      find_next_succ_();
+    trace << "*** next() .... if(done()) = ***" << done() << std::endl;
 
+    return find_next_succ_();
   }
 
-  void
+  bool
   tgta_succ_iterator_product::find_next_succ_()
   {
-
     while (!done())
       {
         if (!tgta_succ_it_->done())
@@ -214,11 +207,12 @@ namespace spot
                 tgta_succ_it_->current_state(), pool_);
             current_acceptance_conditions_
                 = tgta_succ_it_->current_acceptance_conditions();
-            return;
+            return true;
           }
 
         step_();
       }
+    return false;
   }
 
   bool

src/ta/tgtaproduct.hh

@@ -1,6 +1,6 @@
 // -*- coding: utf-8 -*-
-// Copyright (C) 2011, 2012, 2013 Laboratoire de Recherche et Développement
-// de l'Epita (LRDE).
+// Copyright (C) 2011, 2012, 2013, 2014 Laboratoire de Recherche et
+// Développement de l'Epita (LRDE).
 //
 // This file is part of Spot, a model checking library.
 //
@@ -54,12 +54,9 @@ namespace spot
     ~tgta_succ_iterator_product();
 
     // iteration
-    void
-    first();
-    void
-    next();
-    bool
-    done() const;
+    bool first();
+    bool next();
+    bool done() const;
 
     // inspection
     state_product*
@@ -75,8 +72,7 @@ namespace spot
     /// Internal routines to advance to the next successor.
     void
     step_();
-    void
-    find_next_succ_();
+    bool find_next_succ_();
 
     void
     next_kripke_dest();