alternation.hh

// -*- coding: utf-8 -*-
// Copyright (C) by the Spot authors, see the AUTHORS file for details.
//
// 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 <spot/twa/twagraph.hh>
#include <spot/twaalgos/powerset.hh>
#include <utility>
 
namespace spot
{
  class SPOT_API outedge_combiner
  {
  private:
    const twa_graph_ptr& aut_;
    std::map<unsigned, int> state_to_var;
    std::map<int, unsigned> var_to_state;
    bdd vars_;
  public:
    outedge_combiner(const twa_graph_ptr& aut);
    ~outedge_combiner();
    bdd operator()(unsigned st);
    void new_dests(unsigned st, bdd out) const;
  };
 
  template<class I>
  SPOT_API
  unsigned states_and(const twa_graph_ptr& aut, I begin, I end)
  {
    if (begin == end)
      throw std::runtime_error
        ("state_and() expects an non-empty list of states");
    outedge_combiner combiner(aut);
    bdd combination = bddtrue;
    while (begin != end)
      combination &= combiner(*begin++);
    unsigned new_s = aut->new_state();
    combiner.new_dests(new_s, combination);
    return new_s;
  }
 
  template<class T>
  SPOT_API
  unsigned states_and(const twa_graph_ptr& aut,
                      const std::initializer_list<T>& il)
  {
    return states_and(aut, il.begin(), il.end());
  }
 
  SPOT_API
  twa_graph_ptr remove_alternation(const const_twa_graph_ptr& aut,
                                   bool named_states = false,
                                   const output_aborter* aborter = nullptr,
                                   bool raise_if_too_many_sets = true);
 
 
  // Remove universal edges on the fly.
 
  class SPOT_API univ_remover_state: public state
  {
  protected:
    std::set<unsigned> states_;
    bool is_reset_;
 
  public:
    univ_remover_state(const std::set<unsigned>& states);
    univ_remover_state(const univ_remover_state& other)
      : states_(other.states_), is_reset_(other.is_reset_)
    {
    }
    int compare(const state* other) const override;
    size_t hash() const override;
    state* clone() const override;
    const std::set<unsigned>& states() const;
    bool is_reset() const;
  };
 
  class SPOT_API twa_univ_remover: public twa
  {
 
  private:
    const_twa_graph_ptr aut_;
    std::vector<int> state_to_var_;
    std::map<int, unsigned> var_to_state_;
    bdd all_states_;
 
  public:
    twa_univ_remover(const const_twa_graph_ptr& aut);
    void allocate_state_vars();
    const state* get_init_state() const override;
    twa_succ_iterator* succ_iter(const state* s) const override;
    std::string format_state(const state* s) const override;
  };
 
  typedef std::shared_ptr<twa_univ_remover> twa_univ_remover_ptr;
 
  SPOT_API
  twa_univ_remover_ptr remove_univ_otf(const const_twa_graph_ptr& aut);
}