twaalgos: Implement language_map algo

* python/spot/impl.i: Add python bindings.
* spot/twaalgos/langmap.cc: Implement algo.
* spot/twaalgos/langmap.hh: Declare algo.
* spot/twaalgos/Makefile.am: Add new files.
* tests/python/langmap.py: Add tests.
* NEWS: Update.

NEWS

@@ -74,6 +74,9 @@ New in spot 2.2.2.dev (Not yet released)
     deterministic/semi-deterministic/unambiguous should be preserved
     only if they are positive.
 
+  * language_map() and highlight_languages() are new functions used to
+    implement the --highlight-languages command line option described above.
+
   Build:
 
   * The configure script has a new option --enable-c++14, to compile in

python/spot/impl.i

@@ -137,6 +137,7 @@
 #include <spot/twaalgos/stats.hh>
 #include <spot/twaalgos/isdet.hh>
 #include <spot/twaalgos/isunamb.hh>
+#include <spot/twaalgos/langmap.hh>
 #include <spot/twaalgos/simulation.hh>
 #include <spot/twaalgos/postproc.hh>
 #include <spot/twaalgos/product.hh>
@@ -524,6 +525,7 @@ def state_is_accepting(self, src) -> "bool":
 %include <spot/twaalgos/ltl2tgba_fm.hh>
 %include <spot/twaalgos/compsusp.hh>
 %include <spot/twaalgos/determinize.hh>
+%include <spot/twaalgos/langmap.hh>
 %include <spot/twaalgos/magic.hh>
 %include <spot/twaalgos/minimize.hh>
 %include <spot/twaalgos/neverclaim.hh>

spot/twaalgos/Makefile.am

@@ -50,6 +50,7 @@ twaalgos_HEADERS = \
   isdet.hh \
   isunamb.hh \
   isweakscc.hh \
+  langmap.hh \
   lbtt.hh \
   ltl2taa.hh \
   ltl2tgba_fm.hh \
@@ -106,6 +107,7 @@ libtwaalgos_la_SOURCES = \
   isdet.cc \
   isunamb.cc \
   isweakscc.cc \
+  langmap.cc \
   lbtt.cc \
   ltl2taa.cc \
   ltl2tgba_fm.cc \

spot/twaalgos/langmap.cc

+// -*- coding: utf-8 -*-
+// Copyright (C) 2016 Laboratoire de Recherche et Développement de l'Epita.
+//
+// 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/>.
+
+#include <numeric>
+#include <spot/twa/twa.hh>
+#include <spot/twaalgos/complement.hh>
+#include <spot/twaalgos/copy.hh>
+#include <spot/twaalgos/isdet.hh>
+#include <spot/twaalgos/langmap.hh>
+#include <spot/twaalgos/remfin.hh>
+
+namespace spot
+{
+  void highlight_languages(twa_graph_ptr& aut,
+      const std::vector<unsigned>& v)
+  {
+    auto hs = new std::map<unsigned, unsigned>;
+    aut->set_named_prop("highlight-states", hs);
+
+    unsigned n_states = aut->num_states();
+    for (unsigned i = 0; i < n_states; ++i)
+      (*hs)[i] = v[i];
+  }
+
+
+  std::vector<unsigned>
+  language_map(const const_twa_graph_ptr& aut)
+  {
+    if (!is_deterministic(aut))
+      throw std::runtime_error(
+          "language_map only works with deterministic automata");
+
+    unsigned n_states = aut->num_states();
+    std::vector<unsigned> res(n_states);
+    std::iota(std::begin(res), std::end(res), 0);
+
+    std::vector<twa_graph_ptr> alt_init_st_auts(n_states);
+    std::vector<twa_graph_ptr> compl_alt_init_st_auts(n_states);
+
+    // Prepare all automatons needed.
+    for (unsigned i = 0; i < n_states; ++i)
+    {
+      twa_graph_ptr c = copy(aut, twa::prop_set::all());
+      c->set_init_state(i);
+      alt_init_st_auts[i] = c;
+
+      twa_graph_ptr cc =
+        remove_fin(dtwa_complement(copy(c, twa::prop_set::all())));
+      compl_alt_init_st_auts[i] = cc;
+    }
+
+    for (unsigned i = 1; i < n_states; ++i)
+      for (unsigned j = 0; j < i; ++j)
+      {
+        if (res[j] != j)
+          continue;
+
+        if (!alt_init_st_auts[i]->intersects(compl_alt_init_st_auts[j])
+          && (!compl_alt_init_st_auts[i]->intersects(alt_init_st_auts[j])))
+        {
+          res[i] = res[j];
+          break;
+        }
+      }
+
+    return res;
+  }
+}

spot/twaalgos/langmap.hh

+// -*- coding: utf-8 -*-
+// Copyright (C) 2016 Laboratoire de Recherche et Développement de l'Epita.
+//
+// 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/>.
+
+#pragma once
+
+#include <vector>
+#include <spot/twa/twagraph.hh>
+
+namespace spot
+{
+  /// \brief Identify states that recognize the same language.
+  ///
+  /// The returned vector is the same size as the automaton's number of state.
+  /// The number of different values (ignoring occurences) in the vector is the
+  /// total number of recognized languages, states recognizing the same
+  /// language have the same value.
+  ///
+  /// The given automaton must be deterministic.
+  SPOT_API std::vector<unsigned>
+  language_map(const const_twa_graph_ptr& aut);
+
+  /// \brief Color automaton's states that recognize the same language.
+  SPOT_API void
+  highlight_languages(twa_graph_ptr& aut, const std::vector<unsigned>& v);
+}

tests/python/langmap.py

+# -*- coding: utf-8 -*-
+# Copyright (C) 2016 Laboratoire de Recherche et Développement de l'Epita.
+#
+# 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
+import re
+import sys
+
+
+def test_langmap_functions_for(aut, expected):
+    # First, let's get aut's languages map as v.
+    v = ''
+    try:
+        v = spot.language_map(aut)
+    except Exception as e:
+        # If aut is not deterministic and the exception is as expected then
+        # it is ok.
+        if 'language_map only works with deterministic automata' in str(e)\
+                and not spot.is_deterministic(aut):
+                    return
+        else:
+            print(e, file=sys.stderr)
+            exit(1)
+
+    # Now let's check highligthed states.
+    spot.highlight_languages(aut, v)
+    lines = aut.to_str('hoa', '1.1').split('\n')
+    colors_l = []
+    for line in lines:
+        if 'spot.highlight.states' in line:
+            l = [int(w) for w in \
+                    re.search(': (.+?)$', line).group(1).split(' ')]
+            if l[1::2] != expected:
+                print('expected:' + repr(expected) +
+                      ' but got:' + repr(l[1::2]), file=sys.stderr)
+                exit(1)
+
+aut_l = []
+expected_l = []
+
+aut_l.append(spot.translate('(a U b) & GFc & GFd', 'BA', 'deterministic'))
+expected_l.append([0, 1, 1, 1])
+
+aut_l.append(spot.translate('GF(a <-> b) | c', 'BA', 'deterministic'))
+expected_l.append([0, 1, 2, 2])
+
+aut_l.append(spot.translate('GF(a <-> b) | c | X!a', 'BA', 'deterministic'))
+expected_l.append([0, 1, 2, 3, 3])
+
+aut = spot.automaton("""
+HOA: v1
+States: 4
+properties: implicit-labels trans-labels no-univ-branch deterministic complete
+acc-name: Rabin 2
+Acceptance: 4 (Fin(0)&Inf(1))|(Fin(2)&Inf(3))
+Start: 0
+AP: 2 "p0" "p1"
+--BODY--
+State: 0 {0}
+1
+0
+3
+2
+State: 1 {1}
+1
+0
+3
+2
+State: 2 {0 3}
+1
+0
+3
+2
+State: 3 {1 3}
+1
+0
+3
+2
+--END--
+""")
+aut_l.append(aut)
+expected_l.append([0, 0, 0, 0])
+
+# Add a non deterministic test:
+aut_l.append(spot.translate('GF(a <-> XXb) | Xc', 'BA'))
+expected_l.append([])
+
+len_aut = len(aut_l)
+for i in range(0, len_aut):
+    test_langmap_functions_for(aut_l[i], expected_l[i])