bin/autfilt.cc: Add '--highlight-languages' option

* bin/autfilt.cc: Add that option.
* tests/core/highlightstate.test: Add test.
* NEWS: Update.

NEWS

@@ -16,6 +16,9 @@ New in spot 2.2.2.dev (Not yet released)
 
   * the --check option can now take "semi-determinism" as argument.
 
+  * autfilt has a new option '--highlight-languages' that helps to see
+    graphically which states of an automaton recognize the same languages.
+
   Library:
 
   * A twa is required to have at least one state, the initial state.

bin/autfilt.cc

@@ -66,6 +66,7 @@
 #include <spot/twaalgos/isweakscc.hh>
 #include <spot/twaalgos/gtec/gtec.hh>
 #include <spot/twaalgos/totgba.hh>
+#include <spot/twaalgos/langmap.hh>
 
 static const char argp_program_doc[] ="\
 Convert, transform, and filter omega-automata.\v\
@@ -98,6 +99,7 @@ enum {
   OPT_HIGHLIGHT_NONDET_EDGES,
   OPT_HIGHLIGHT_NONDET_STATES,
   OPT_HIGHLIGHT_WORD,
+  OPT_HIGHLIGHT_LANGUAGES,
   OPT_INSTUT,
   OPT_INCLUDED_IN,
   OPT_INHERENTLY_WEAK_SCCS,
@@ -329,6 +331,8 @@ static const argp_option options[] =
       "highlight nondeterministic states and edges with color NUM", 0},
     { "highlight-word", OPT_HIGHLIGHT_WORD, "[NUM,]WORD", 0,
       "highlight one run matching WORD using color NUM", 0},
+    { "highlight-languages", OPT_HIGHLIGHT_LANGUAGES, nullptr, 0 ,
+      "highlight states that recognize same language with same color", 0},
     /**************************************************/
     { nullptr, 0, nullptr, 0,
       "If any option among --small, --deterministic, or --any is given, "
@@ -470,6 +474,7 @@ static bool opt_sep_sets = false;
 static const char* opt_sat_minimize = nullptr;
 static int opt_highlight_nondet_states = -1;
 static int opt_highlight_nondet_edges = -1;
+static bool opt_highlight_languages = false;
 
 static spot::twa_graph_ptr
 ensure_deterministic(const spot::twa_graph_ptr& aut, bool nonalt = false)
@@ -631,7 +636,9 @@ parse_opt(int key, char* arg, struct argp_state*)
           }
       }
       break;
-
+    case OPT_HIGHLIGHT_LANGUAGES:
+      opt_highlight_languages = true;
+      break;
     case OPT_INSTUT:
       if (!arg || (arg[0] == '1' && arg[1] == 0))
         opt_instut = 1;
@@ -1205,6 +1212,9 @@ namespace
       if (opt_highlight_nondet_edges >= 0)
         spot::highlight_nondet_edges(aut, opt_highlight_nondet_edges);
 
+      if (opt_highlight_languages)
+        spot::highlight_languages(aut, spot::language_map(aut));
+
       if (!opt->hl_words.empty())
         for (auto& word_aut: opt->hl_words)
           {

tests/core/highlightstate.test

@@ -0,0 +1,65 @@
+#!/bin/sh
+# -*- coding: utf-8 -*-
+# Copyright (C) 2016 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/>.
+
+. ./defs
+set -e
+
+autfilt=autfilt
+
+cat >aut.hoa <<'EOF'
+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--
+EOF
+
+cat >expected << 'EOF'
+spot.highlight.states: 0 0 1 0 2 0 3 0
+EOF
+
+$autfilt aut.hoa --highlight-languages -H1.1 | grep -e 'spot.highlight.states'\
+  > res
+
+diff expected res