Add count_nondet_states(aut) and is_deterministic(aut).

* src/tgbaalgos/isdet.cc, src/tgbaalgos/isdet.hh: New files.
* src/tgbaalgos/Makefile.am: Add them.
* wrap/python/spot.i: Wrap them.
* wrap/python/ajax/spot.in: Display count of nondeterministic
states.
* src/tgbatest/ltl2tgba.cc (-kt): Likewise.
* NEWS: Upadte.

NEWS

@@ -35,6 +35,9 @@ New in spot 0.9.2a:
     minimization it cases it would produce a deterministic automaton
     that is bigger than the original TGBA.  So this effectively
     gives the choice between less states or more determinism.
+  * new functions is_deterministic() and count_nondet_states()
+    (The count of nondeterministic states is now displayed on
+    automata generated with the web interface.)
   * Useful command-line tools are now installed in addition
     to the library.  Some of these tools were originally written
     for our test suite and had evolved organically into useful
@@ -48,8 +51,9 @@ New in spot 0.9.2a:
                (e.g., match only safety formulas that are larger than
 	       some given size).  Besides being used as a "grep" tool
 	       for formulas, this can also be used to convert
-	       files of formulas between different syntaxes, and apply
-	       some simplifications.
+	       files of formulas between different syntaxes, apply
+	       some simplifications, check whether to formulas are
+	       equivalent, ...
 
 New in spot 0.9.2 (2012-07-02):
 

src/tgbaalgos/Makefile.am

@@ -40,6 +40,7 @@ tgbaalgos_HEADERS = \
   emptiness.hh \
   emptiness_stats.hh \
   gv04.hh \
+  isdet.hh \
   lbtt.hh \
   ltl2taa.hh \
   ltl2tgba_fm.hh \
@@ -77,6 +78,7 @@ libtgbaalgos_la_SOURCES = \
   eltl2tgba_lacim.cc \
   emptiness.cc \
   gv04.cc \
+  isdet.cc \
   lbtt.cc \
   ltl2taa.cc \
   ltl2tgba_fm.cc \

src/tgbaalgos/isdet.cc

+// -*- coding: utf-8 -*-
+// Copyright (C) 2012 Laboratoire de Recherche et Développement de
+// l'Epita (LRDE).
+//
+// This file is part of Spot, a model checking library.
+//
+// Spot is free software; you can redistribute it and/or modify it
+// under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// Spot is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+// or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+// License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Spot; see the file COPYING.  If not, write to the Free
+// Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+// 02111-1307, USA.
+
+#include "tgbaalgos/isdet.hh"
+#include <set>
+#include <deque>
+
+namespace spot
+{
+  namespace
+  {
+    static
+    unsigned
+    count_nondet_states_aux(const tgba* aut, bool count = true)
+    {
+      unsigned res = 0;
+      typedef std::set<const state*, state_ptr_less_than> seen_set;
+      typedef std::deque<const state*> todo_list;
+
+      seen_set seen;
+      todo_list todo;
+      {
+	const state* s = aut->get_init_state();
+	seen.insert(s);
+	todo.push_back(s);
+      }
+      while (!todo.empty())
+	{
+	  const state* src = todo.front();
+	  todo.pop_front();
+
+	  tgba_succ_iterator* i = aut->succ_iter(src);
+	  tgba_succ_iterator* j = aut->succ_iter(src);
+	  unsigned in = 0;
+	  bool nondeterministic = false;
+	  for (i->first(); !i->done(); i->next())
+	    {
+	      // If we know the state is nondeterministic, just skip the
+	      // test for the remaining transitions.  But don't break
+	      // the loop, because we still have to record the
+	      // destination states.
+	      if (!nondeterministic)
+		{
+		  ++in;
+		  // Move j to the transition that follows i.
+		  j->first();
+		  for (unsigned jn = 0; jn < in; ++jn)
+		    j->next();
+		  // Make sure transitions after i are not conflicting.
+		  while (!j->done())
+		    {
+		      if ((i->current_condition() & j->current_condition())
+			  != bddfalse)
+			{
+			  nondeterministic = true;
+			  break;
+			}
+		      j->next();
+		    }
+		}
+	      const state* dst = i->current_state();
+	      if (seen.insert(dst).second)
+		todo.push_back(dst);
+	      else
+		dst->destroy();
+	    }
+	  delete j;
+	  delete i;
+	  res += nondeterministic;
+	  if (!count && nondeterministic)
+	    break;
+	}
+      for (seen_set::const_iterator i = seen.begin(); i != seen.end();)
+	{
+	  const state* s = *i++;
+	  s->destroy();
+	}
+      return res;
+    }
+  }
+
+  unsigned
+  count_nondet_states(const tgba* aut)
+  {
+    return count_nondet_states_aux(aut);
+  }
+
+  bool
+  is_deterministic(const tgba* aut)
+  {
+    return !!count_nondet_states_aux(aut, false);
+  }
+}

src/tgbaalgos/isdet.hh

+// -*- coding: utf-8 -*-
+// Copyright (C) 2012 Laboratoire de Recherche et
+// Développement de l'Epita (LRDE).
+//
+// This file is part of Spot, a model checking library.
+//
+// Spot is free software; you can redistribute it and/or modify it
+// under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// Spot is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+// or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+// License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Spot; see the file COPYING.  If not, write to the Free
+// Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+// 02111-1307, USA.
+
+#ifndef SPOT_TGBAALGOS_ISDET_HH
+# define SPOT_TGBAALGOS_ISDET_HH
+
+# include "tgba/tgba.hh"
+
+namespace spot
+{
+  /// \addtogroup tgba_misc
+  /// @{
+
+  /// \brief Count the number of non-deterministic states in \a aut.
+  ///
+  /// The automaton is deterministic if it has 0 nondeterministic states,
+  /// but it is more efficient to call is_deterministic() if you do not
+  /// care about the number of nondeterministic states.
+  unsigned count_nondet_states(const tgba* aut);
+
+  /// \brief Return true iff \a aut is deterministic.
+  ///
+  /// This function is more efficient than count_nondet_states() when
+  /// the automaton is nondeterministic, because it can return before
+  /// the entire automaton has been explored.
+  bool is_deterministic(const tgba* aut);
+
+  /// @}
+}
+
+#endif // SPOT_TGBAALGOS_ISDET_HH

src/tgbatest/ltl2tgba.cc

@@ -63,6 +63,7 @@
 #include "tgbaalgos/scc.hh"
 #include "tgbaalgos/emptiness_stats.hh"
 #include "tgbaalgos/scc.hh"
+#include "tgbaalgos/isdet.hh"
 #include "kripkeparse/public.hh"
 #include "tgbaalgos/simulation.hh"
 
@@ -1367,6 +1368,8 @@ main(int argc, char** argv)
 	      break;
 	    case 13:
 	      sub_stats_reachable(a).dump(std::cout);
+	      std::cout << "nondeterministic states: "
+			<< count_nondet_states(a) << std::endl;
 	      break;
 	    case 14:
 	      if (minimized == 0)

wrap/python/ajax/spot.in

@@ -300,11 +300,17 @@ def render_formula(f):
     spot.dotty(dotsrc, f)
     render_dot_maybe(dotsrc.str(), False)
 
-def print_stats(automaton):
+def print_stats(automaton, detinfo = False):
     stats = spot.stats_reachable(automaton)
     unbufprint("<p>%d state" % stats.states)
     if stats.states > 1:
         unbufprint("s")
+    if detinfo:
+        nondet = spot.count_nondet_states(automaton)
+        if nondet == 0:
+            unbufprint(" (deterministic)")
+        else:
+            unbufprint(" (%d nondeterministic)" % nondet)
     unbufprint(", %d transition" % stats.transitions)
     if stats.transitions > 1:
         unbufprint("s")
@@ -314,8 +320,8 @@ def print_stats(automaton):
             unbufprint(", %d acceptance condition" % count)
             if count > 1:
                 unbufprint("s")
-                acc = automaton.all_acceptance_conditions()
-                unbufprint(": " + spot.bdd_format_accset(automaton.get_dict(), acc))
+            acc = automaton.all_acceptance_conditions()
+            unbufprint(": " + spot.bdd_format_accset(automaton.get_dict(), acc))
         else:
             unbufprint(", no acceptance condition (all cycles are accepting)")
     unbufprint("</p>\n")
@@ -674,7 +680,7 @@ if output_type == 'a':
         unbufprint('<div class="neverclaim">%s</div>' % cgi.escape(s.str()))
         del s
     else: # 't' or 's'
-        dont_run_dot = print_stats(degen)
+        dont_run_dot = print_stats(degen, True)
         render_automaton(degen, dont_run_dot, issba)
     degen = 0
     automaton = 0

wrap/python/spot.i

@@ -108,6 +108,7 @@ namespace std {
 #include "tgbaalgos/safety.hh"
 #include "tgbaalgos/sccfilter.hh"
 #include "tgbaalgos/stats.hh"
+#include "tgbaalgos/isdet.hh"
 #include "tgbaalgos/simulation.hh"
 
 #include "tgbaparse/public.hh"
@@ -272,6 +273,7 @@ using namespace spot;
 %include "tgbaalgos/safety.hh"
 %include "tgbaalgos/sccfilter.hh"
 %include "tgbaalgos/stats.hh"
+%include "tgbaalgos/isdet.hh"
 %include "tgbaalgos/simulation.hh"
 
 %include "tgbaparse/public.hh"