spot/spot/twaalgos/remprop.cc

// -*- coding: utf-8 -*-
// Copyright (C) 2015 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/>.

#include <spot/twaalgos/remprop.hh>
#include <spot/twaalgos/mask.hh>
#include <spot/misc/casts.hh>
#include <ctype.h>
#include <sstream>

namespace spot
{
  namespace
  {
    static
    void unexpected_char(const char* arg, const char* pos)
    {
      std::ostringstream out;
      out << "unexpected ";
      if (isprint(*pos))
	out << '\'' << *pos << '\'';
      else
	out << "character";
      out << " at position " << pos - arg << " in '";
      out << arg << '\'';
      throw std::invalid_argument(out.str());
    }
  }


  void remove_ap::add_ap(const char* arg)
  {
    auto start = arg;
    while (*start)
      {
	while (*start == ' ' || *start == '\t')
	  ++start;
	if (!*start)
	  break;
	if (*start == ',' || *start == '=')
	  unexpected_char(arg, start);
	formula the_ap = nullptr;

	if (*start == '"')
	  {
	    auto end = ++start;
	    while (*end && *end != '"')
	      {
		if (*end == '\\')
		  ++end;
		++end;
	      }
	    if (!*end)
	      {
		std::string s = "missing closing '\"' in ";
		s += arg;
		throw std::invalid_argument(s);
	      }
	    std::string ap(start, end - start);
	    the_ap = formula::ap(ap);
	    do
	      ++end;
	    while (*end == ' ' || *end == '\t');
	    start = end;
	  }
	else
	  {
	    auto end = start;
	    while (*end && *end != ',' && *end != '=')
	      ++end;
	    auto rend = end;
	    while (rend > start && (rend[-1] == ' ' || rend[-1] == '\t'))
	      --rend;
	    std::string ap(start, rend - start);
	    the_ap = formula::ap(ap);
	    start = end;
	  }
	if (*start)
	  {
	    if (!(*start == ',' || *start == '='))
	      unexpected_char(arg, start);
	    if (*start == '=')
	      {
		do
		  ++start;
		while (*start == ' ' || *start == '\t');
		if (*start == '0')
		  props_neg.insert(the_ap);
		else if (*start == '1')
		  props_pos.insert(the_ap);
		else
		  unexpected_char(arg, start);
		the_ap = nullptr;
		do
		  ++start;
		while (*start == ' ' || *start == '\t');
	      }
	    if (*start)
	      {
		if (*start != ',')
		  unexpected_char(arg, start);
		++start;
	      }
	  }
	if (the_ap)
	  props_exist.insert(the_ap);
      }
  }

  twa_graph_ptr remove_ap::strip(const_twa_graph_ptr aut) const
  {
    bdd restrict = bddtrue;
    bdd exist = bddtrue;
    auto d = aut->get_dict();

    twa_graph_ptr res = make_twa_graph(d);
    res->copy_ap_of(aut);
    res->prop_copy(aut, { true, true, false, false });
    res->copy_acceptance_of(aut);

    for (auto ap: props_exist)
      {
	int v = d->has_registered_proposition(ap, aut);
	if (v >= 0)
	  {
	    exist &= bdd_ithvar(v);
	    d->unregister_variable(v, res);
	  }
      }
    for (auto ap: props_pos)
      {
	int v = d->has_registered_proposition(ap, aut);
	if (v >= 0)
	  {
	    restrict &= bdd_ithvar(v);
	    d->unregister_variable(v, res);
	  }
      }
    for (auto ap: props_neg)
      {
	int v = d->has_registered_proposition(ap, aut);
	if (v >= 0)
	  {
	    restrict &= bdd_nithvar(v);
	    d->unregister_variable(v, res);
	  }
      }

    transform_accessible(aut, res, [&](unsigned, bdd& cond,
				       acc_cond::mark_t&, unsigned)
                         {
			   cond = bdd_restrict(bdd_exist(cond, exist),
					       restrict);
                         });
    return res;
  }
}