introduce check_determinism()

* spot/twaalgos/isdet.hh, spot/twaalgos/isdet.cc (check_determinism):
New function.
* NEWS: Mention it.
* tests/python/semidet.py: New file.
* tests/Makefile.am: Add it.

NEWS

@@ -209,6 +209,9 @@ New in spot 2.4.2.dev (not yet released)
     controllers in the format required by the synthesis tools
     competition SYNTCOMP.
 
+  - The new function spot::check_determinism() sets both
+    prop_semi_deterministic() and prop_universal() appropriately.
+
   Deprecation notices:
 
   (These functions still work but compilers emit warnings.)

spot/twaalgos/isdet.cc

@@ -162,11 +162,14 @@ namespace spot
     return res;
   }
 
-  bool
+  namespace
-  is_semi_deterministic(const const_twa_graph_ptr& aut)
+  {
+    static bool
+    check_semi_determism(const const_twa_graph_ptr& aut, bool and_determinism)
     {
       trival sd = aut->prop_semi_deterministic();
-    if (sd.is_known())
+      if (sd.is_known() &&
+          (!and_determinism || aut->prop_universal().is_known()))
         return sd.is_true();
       scc_info si(aut);
       si.determine_unknown_acceptance();
@@ -201,7 +204,48 @@ namespace spot
     done:
       std::const_pointer_cast<twa_graph>(aut)
         ->prop_semi_deterministic(semi_det);
+      if (semi_det && and_determinism)
+        {
+          bool det = true;
+          nscc = si.scc_count();
+          do // iterator of SCCs in reverse topological order
+            {
+              --nscc;
+              if (!si.is_accepting_scc(nscc) && !reachable_from_acc[nscc])
+                {
+                  for (unsigned src: si.states_of(nscc))
+                    {
+                      bdd available = bddtrue;
+                      for (auto& t: aut->out(src))
+                        if (!bdd_implies(t.cond, available))
+                          {
+                            det = false;
+                            goto done2;
+                          }
+                        else
+                          {
+                            available -= t.cond;
+                          }
+                    }
+                }
+            }
+          while (nscc);
+        done2:
+          std::const_pointer_cast<twa_graph>(aut)->prop_universal(det);
+        }
       return semi_det;
     }
+  }
+
+  bool
+  is_semi_deterministic(const const_twa_graph_ptr& aut)
+  {
+    return check_semi_determism(aut, false);
+  }
+
+  void check_determinism(twa_graph_ptr aut)
+  {
+    check_semi_determism(aut, true);
+  }
 
 }

spot/twaalgos/isdet.hh

@@ -91,5 +91,7 @@ namespace spot
   SPOT_API bool
   is_semi_deterministic(const const_twa_graph_ptr& aut);
 
-
+  /// \brief Set the deterministic and semi-deterministic properties
+  /// appropriately.
+  SPOT_API void check_determinism(twa_graph_ptr aut);
 }

tests/Makefile.am

@@ -379,6 +379,7 @@ TESTS_python = \
   python/sbacc.py \
   python/sccfilter.py \
   python/sccinfo.py \
+  python/semidet.py \
   python/setacc.py \
   python/setxor.py \
   python/simstate.py \

tests/python/semidet.py

@@ -0,0 +1,39 @@
+# -*- mode: python; coding: utf-8 -*-
+# Copyright (C) 2017 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 3 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import spot
+
+formulas = [('(Gp0 | Fp1) M 1', False, True),
+            ('(!p1 U p1) U X(!p0 -> Fp1)', False, True),
+            ('(p1 | (Fp0 R (p1 W p0))) M 1', True, True),
+            ('!G(F(p1 & Fp0) W p1)', False, True),
+            ('X(!p0 W Xp1)', False, False),
+            ('FG(p0)', False, True) ]
+
+for f, isd, issd in formulas:
+    print(f)
+    aut = spot.translate(f)
+    # The formula with isd=True, issd=True is the only one
+    # for which both properties are already set.
+    assert (aut.prop_deterministic().is_maybe() or
+            aut.prop_semi_deterministic().is_maybe() or
+            isd == issd)
+    spot.check_determinism(aut)
+    assert aut.prop_deterministic() == isd
+    assert aut.prop_semi_deterministic() == issd