dstarparse: Preliminary work on a parser for ltl2dstar.

Supports reading Rabin and Streett automata, and converting them to
nondeterministic Büchi automata (for Rabin) or TGBA (for Streett).

* src/dstarparse/Makefile.am, src/dstarparse/dstarparse.yy,
src/dstarparse/dstarscan.ll, src/dstarparse/fmterror.cc,
src/dstarparse/parsedecl.hh, src/dstarparse/public.hh,
src/dstarparse/nra2nba.cc, src/dstarparse/nsa2tgba.cc: New files.
* configure.ac, src/Makefile.am, README: Adjust.
* src/tgbatest/ltl2tgba.cc: Add options -XD, -XDB.
* src/tgbatest/dstar.test: New file.
* src/tgbatest/Makefile.am (TESTS): Add it.

src/dstarparse/public.hh

@@ -0,0 +1,120 @@
+// -*- coding: utf-8 -*-
+// Copyright (C) 2013 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/>.
+
+#ifndef SPOT_DSTARPARSE_PUBLIC_HH
+# define SPOT_DSTARPARSE_PUBLIC_HH
+
+# include "tgba/tgbaexplicit.hh"
+# include "misc/location.hh"
+# include "ltlenv/defaultenv.hh"
+# include <string>
+# include <list>
+# include <utility>
+# include <iosfwd>
+# include <misc/bitvect.hh>
+
+namespace spot
+{
+  /// \addtogroup tgba_io
+  /// @{
+
+  /// \brief A parse diagnostic with its location.
+  typedef std::pair<spot::location, std::string> dstar_parse_error;
+  /// \brief A list of parser diagnostics, as filled by parse.
+  typedef std::list<dstar_parse_error> dstar_parse_error_list;
+
+  enum dstar_type { Rabin, Streett };
+
+  /// \brief Temporary encoding of an omega automaton produced by
+  /// ltl2dstar.
+  struct SPOT_API dstar_aut
+  {
+    // Transition structure of the automaton.
+    // This is encoded as a TGBA without acceptance condition.
+    tgba_explicit_number* aut;
+    /// Type of the acceptance.
+    dstar_type type;
+    /// Number of acceptance pairs.
+    size_t accpair_count;
+    /// \brief acceptance sets encoded as 2*num_state bit-vectors of
+    /// num_pairs bits
+    ///
+    /// Assuming $F=\{(L_0,U_0),\ldots,(L_i,U_i),\ldots\}$,
+    /// $s\in L_i$ iff <code>accsets->at(s * 2).get(i)$</code>,
+    /// an $s\in $U_i$ iff <code>accsets->at(s * 2 + 1).get(i)</code>.
+    bitvect_array* accsets;
+
+    ~dstar_aut()
+    {
+      delete aut;
+      delete accsets;
+    }
+  };
+
+
+  /// \brief Build a spot::tgba_explicit from ltl2dstar's output.
+  /// \param filename The name of the file to parse.
+  /// \param error_list A list that will be filled with
+  ///        parse errors that occured during parsing.
+  /// \param dict The BDD dictionary where to use.
+  /// \param env The environment of atomic proposition into which parsing
+  ///        should take place.
+  /// \param debug When true, causes the parser to trace its execution.
+  /// \return A pointer to the tgba built from \a filename, or
+  ///        0 if the file could not be opened.
+  ///
+  /// Note that the parser usually tries to recover from errors.  It can
+  /// return an non zero value even if it encountered error during the
+  /// parsing of \a filename.  If you want to make sure \a filename
+  /// was parsed succesfully, check \a error_list for emptiness.
+  ///
+  /// \warning This function is not reentrant.
+  SPOT_API dstar_aut*
+  dstar_parse(const std::string& filename,
+	      dstar_parse_error_list& error_list,
+	      bdd_dict* dict,
+	      ltl::environment& env = ltl::default_environment::instance(),
+	      bool debug = false);
+
+  /// \brief Format diagnostics produced by spot::dstar_parse.
+  /// \param os Where diagnostics should be output.
+  /// \param filename The filename that should appear in the diagnostics.
+  /// \param error_list The error list filled by spot::ltl::parse while
+  ///        parsing \a ltl_string.
+  /// \return \c true iff any diagnostic was output.
+  SPOT_API bool
+  format_dstar_parse_errors(std::ostream& os,
+			    const std::string& filename,
+			    dstar_parse_error_list& error_list);
+
+
+  /// \brief Convert a non-deterministic Rabin automaton into a
+  /// non-deterministic Büchi automaton.
+  SPOT_API
+  tgba* nra_to_nba(const dstar_aut* nra);
+
+  /// \brief Convert a non-deterministic Streett automaton into a
+  /// non-deterministic tgba.
+  SPOT_API
+  tgba* nsa_to_tgba(const dstar_aut* nra);
+
+  /// @}
+}
+
+#endif // SPOT_DSTARPARSE_PUBLIC_HH