// Copyright (C) 2010, 2011, 2012 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 2 of the License, or
// (at your option) any later version.
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// ANY WARRANTY; without even the implied warranty of MERCHANta_explicitBILITY
// or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
// License for more deta_explicitils.
//
// 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_TA_TGTA_HH
# define SPOT_TA_TGTA_HH

#include "tgba/tgba.hh"

namespace spot
{

  /// \brief A Transition-based Generalized Testing Automaton (TGTA).
  /// \ingroup ta_essentials
  ///
  ///  Transition-based Generalized Testing Automaton (TGTA) is a new kind of
  /// automaton that combines features from both TA and TGBA.
  /// From TA, we take the idea of labeling transitions with changesets,
  /// however we remove the use of livelock-acceptance (because it may require
  /// a two-pass emptiness check), and the implicit stuttering.  From TGBA, we
  /// inherit the use of transition-based generalized acceptance conditions.
  ///  The resulting Chimera, which we call \emph{Transition-based
  ///  Generalized Testing Automaton} (TGTA), accepts only
  ///  stuttering-insensitive languages like TA, and inherits advantages from
  ///  both TA and TGBA: it has a simple one-pass emptiness-check procedure
  /// (the same as algorithm the one for TGBA), and can benefit from reductions
  ///  based on the stuttering of the properties pretty much like a TA.
  ///  Livelock acceptance states, which are no longer supported are emulated
  ///using states with a Büchi accepting self-loop labeled by empty changeset.
  ///
  /// Browsing such automaton can be achieved using two functions:
  /// \c get_initial_state and \c
  /// succ_iter. The former returns the initial state(s) while the latter lists
  /// the successor states of any state. A second implementation of \c succ_iter
  /// returns only the successors reached through a changeset passed as
  /// a parameter.
  ///
  /// Note that although this is a transition-based automata,
  /// we never represent transitions!  Transition informations are
  /// obtained by querying the iterator over the successors of
  /// a state.


  class tgta : public tgba
  {

  protected:
    tgta();
  public:

    virtual
    ~tgta();

    /// \brief Get an iterator over the successors of \a state
    /// filtred by the value of the changeset on transitions between the
    /// \a state and his successors
    ///
    /// The iterator has been allocated with \c new.  It is the
    /// responsability of the caller to \c delete it when no
    /// longer needed.
    ///
    virtual tgba_succ_iterator*
    succ_iter_by_changeset(const spot::state* s, bdd change_set) const =0;

  };

}

#endif // SPOT_TA_TGTA_HH