Introduce cube data structure

* README, configure.ac, spot/Makefile.am,
spot/twacube/Makefile.am, spot/twacube/cube.cc,
spot/twacube/cube.hh, tests/Makefile.am,
tests/core/.gitignore, tests/core/cube.cc,
tests/core/cube.test: here.

tests/Makefile.am

@@ -67,6 +67,7 @@ check_PROGRAMS = \
   core/checkpsl \
   core/checkta \
   core/consterm \
+  core/cube \
   core/emptchk \
   core/equals \
   core/graph \
@@ -118,6 +119,7 @@ core_randtgba_SOURCES = core/randtgba.cc
 core_taatgba_SOURCES = core/taatgba.cc
 core_tgbagraph_SOURCES = core/twagraph.cc
 core_consterm_SOURCES = core/consterm.cc
+core_cube_SOURCES = core/cube.cc
 core_equals_SOURCES = core/equalsf.cc
 core_kind_SOURCES = core/kind.cc
 core_length_SOURCES = core/length.cc
@@ -152,6 +154,7 @@ core_tunenoform_CPPFLAGS = $(AM_CPPFLAGS) -DNENOFORM -DUNABBREV='"^ieFG"'
 
 TESTS_tl = \
   core/bare.test \
+  core/cube.test \
   core/parse.test \
   core/parseerr.test \
   core/utf8.test \

tests/core/.gitignore

@@ -8,6 +8,7 @@ checkpsl
 checkta
 complement
 consterm
+cube
 defs
 .deps
 *.dot

tests/core/cube.cc

@@ -0,0 +1,58 @@
+// -*- coding: utf-8 -*-
+// Copyright (C) 2015, 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 <iostream>
+#include <spot/twacube/cube.hh>
+
+int main()
+{
+  std::vector<std::string> aps = {"a", "b", "c", "d", "e"};
+  spot::cubeset cs(aps.size());
+  spot::cube mc = cs.alloc();
+  cs.set_true_var(mc, 0);
+  cs.set_false_var(mc, 3);
+  std::cout << "size : " << cs.size() << '\n';
+  std::cout << "cube : " << cs.dump(mc, aps) << '\n';
+  std::cout << "valid : " << cs.is_valid(mc) << '\n';
+  std::cout << "intersect(c,c) : " << cs.intersect(mc, mc) << '\n';
+
+  spot::cube mc1 = cs.alloc();
+  cs.set_false_var(mc1, 0);
+  cs.set_true_var(mc1, 1);
+  std::cout << "size : " << cs.size() << '\n';
+  std::cout << "cube : " << cs.dump(mc1, aps) << '\n';
+  std::cout << "valid : " << cs.is_valid(mc1) << '\n';
+  std::cout << "intersect(c1,c1) : " << cs.intersect(mc1, mc1) << '\n';
+  std::cout << "intersect(c,c1) : " << cs.intersect(mc, mc1) << '\n';
+  std::cout << "intersect(c1,c) : " << cs.intersect(mc1, mc) << '\n';
+
+  spot::cube mc2 = cs.alloc();
+  cs.set_true_var(mc2, 1);
+  cs.set_true_var(mc2, 3);
+  std::cout << "size : " << cs.size() << '\n';
+  std::cout << "cube : " << cs.dump(mc2, aps) << '\n';
+  std::cout << "valid : " << cs.is_valid(mc2) << '\n';
+  std::cout << "intersect(c2,c1) : " << cs.intersect(mc1, mc2) << '\n';
+  std::cout << "intersect(c2,c) : " << cs.intersect(mc, mc2) << '\n';
+
+  cs.release(mc2);
+  cs.release(mc1);
+  cs.release(mc);
+}

tests/core/cube.test

@@ -0,0 +1,53 @@
+#!/bin/sh
+# -*- coding: utf-8 -*-
+# Copyright (C) 2015, 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/>.
+
+# While running some benchmark, Tomáš Babiak found that Spot took too
+# much time (i.e. >1h) to translate those six formulae.  It turns out
+# that the WDBA minimization was performed after the degeneralization
+# algorithm, while this is not necessary (WDBA will produce a BA, so
+# we may as well skip degeneralization).  Translating these formulae
+# in the test-suite ensure that they don't take too much time (the
+# buildfarm will timeout if it does).
+
+. ./defs
+
+set -e
+
+run 0 ../cube > stdout
+
+cat >expected <<EOF
+size : 5
+cube : a&!d
+valid : 1
+intersect(c,c) : 1
+size : 5
+cube : !a&b
+valid : 1
+intersect(c1,c1) : 1
+intersect(c,c1) : 0
+intersect(c1,c) : 0
+size : 5
+cube : b&d
+valid : 1
+intersect(c2,c1) : 1
+intersect(c2,c) : 0
+EOF
+
+diff stdout expected