Add a new type of automata: State-labeled Alternating Büchi

Automata (SABA).

* src/saba/saba.hh, src/saba/saba.cc, src/saba/sabastate.hh,
src/saba/sabasucciter.hh: New.  Interface for
SABA (State-labeled Alternating Büchi Automata).
* src/saba/explicitstateconjunction.cc,
src/saba/explicitstateconjunction.hh: New.  Default
implementation for a conjunction of states.
* src/saba/Makefile.am: New.
* src/Makefile.am, configure.ac: Adjust.
* src/sabaalgos/sabareachiter.cc,
src/sabaalgos/sabareachiter.hh: New.  Iterate over all reachable
states of a spot::saba.
* src/sabaalgos/sabadotty.cc, src/sabaalgos/sabadotty.hh: New.
Print reachable states in dot format.
* src/sabaalgos/Makefile.am: New.

src/saba/sabasucciter.hh

@@ -0,0 +1,160 @@
+// Copyright (C) 2009  Laboratoire d'Informatique de Paris 6 (LIP6),
+// département Systèmes Répartis Coopératifs (SRC), Université Pierre
+// et Marie Curie.
+//
+// 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_SABA_SABASUCCITER_HH
+# define SPOT_SABA_SABASUCCITER_HH
+
+#include "sabastate.hh"
+
+namespace spot
+{
+  /// \brief Iterate over a conjunction of saba_state.
+  /// \ingroup saba_essentials
+  ///
+  /// This class provides the basic functionalities required to
+  /// iterate over a conjunction of states of a saba.
+  class saba_state_conjunction
+  {
+  public:
+    virtual
+    ~saba_state_conjunction()
+    {
+    }
+
+    /// \name Iteration
+    //@{
+
+    /// \brief Position the iterator on the first successor of the conjunction
+    /// (if any).
+    ///
+    /// This method can be called several times to make multiple
+    /// passes over successors.
+    ///
+    /// \warning One should always call \c done() to
+    /// ensure there is a successor, even after \c first().  A
+    /// common trap is to assume that there is at least one
+    /// successor: this is wrong.
+    virtual void first() = 0;
+
+    /// \brief Jump to the next successor (if any).
+    ///
+    /// \warning Again, one should always call \c done() to ensure
+    /// there is a successor.
+    virtual void next() = 0;
+
+    /// \brief Check whether the iteration over a conjunction of states
+    /// is finished.
+    ///
+    /// This function should be called after any call to \c first()
+    /// or \c next() and before any enquiry about the current state.
+    virtual bool done() const = 0;
+
+    //@}
+
+    /// \name Inspection
+    //@{
+
+    /// \brief Get the state of the current successor.
+    ///
+    /// Note that the same state may occur at different points
+    /// in the iteration.  These actually correspond to the same
+    /// destination.  It just means there were several transitions,
+    /// with different conditions, leading to the same state.
+    ///
+    /// \warning the state is allocated with new, its deletion is
+    /// the responsibility of the caller.
+    virtual saba_state* current_state() const = 0;
+
+    //@}
+
+    /// Duplicate a saba_state conjunction.
+    virtual saba_state_conjunction* clone() const = 0;
+  };
+
+
+  /// \brief Iterate over the successors of a saba_state.
+  /// \ingroup saba_essentials
+  ///
+  /// This class provides the basic functionalities required to
+  /// iterate over the successors of a state of a saba. Since
+  /// transitions of an alternating automaton are defined as a
+  /// boolean function with conjunctions (universal) and
+  /// disjunctions (non-deterministic),
+  class saba_succ_iterator
+  {
+  public:
+    virtual
+    ~saba_succ_iterator()
+    {
+    }
+
+    /// \name Iteration
+    //@{
+
+    /// \brief Position the iterator on the first conjunction
+    /// of successors (if any).
+    ///
+    /// This method can be called several times to make multiple
+    /// passes over successors.
+    ///
+    /// \warning One should always call \c done() to
+    /// ensure there is a successor, even after \c first().  A
+    /// common trap is to assume that there is at least one
+    /// successor: this is wrong.
+    virtual void first() = 0;
+
+    /// \brief Jump to the next conjunction of successors (if any).
+    ///
+    /// \warning Again, one should always call \c done() to ensure
+    /// there is a successor.
+    virtual void next() = 0;
+
+    /// \brief Check whether the iteration is finished.
+    ///
+    /// This function should be called after any call to \c first()
+    /// or \c next() and before any enquiry about the current state.
+    ///
+    /// The usual way to do this is with a \c for loop.
+    /// \code
+    ///    for (s->first(); !s->done(); s->next())
+    ///      ...
+    /// \endcode
+    virtual bool done() const = 0;
+
+    //@}
+
+    /// \name Inspection
+    //@{
+
+    /// \brief Get current conjunction of successor states.
+    virtual saba_state_conjunction* current_conjunction() const = 0;
+
+    /// \brief Get the condition on the transition leading to this successor.
+    ///
+    /// This is a boolean function of atomic propositions.
+    virtual bdd current_condition() const = 0;
+
+    //@}
+  };
+}
+
+
+#endif // SPOT_TGBA_SUCCITER_HH