Add a new algorithm (from Tauriainen) to translate LTL formulae to

TGBA which uses TAA as an intermediate representation.  This is a
basic version, optimizations and enhancements will come later.

* src/tgbaalgos/ltl2taa.cc, src/tgbaalgos/ltl2taa.hh: The algortihm.
* src/tgbaalgos/Makefile.am: Adjust.
* src/tgbatest/ltl2tgba: New option: -taa, which uses this new
translation algorithm.
* src/tgbatest/spotlbtt.test: Add ltl2tgba -taa.

src/tgbaalgos/ltl2taa.hh

@@ -0,0 +1,54 @@
+// 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_TAAALGOS_LTL2TAA_HH_
+# define SPOT_TAAALGOS_LTL2TAA_HH_
+
+#include "ltlast/formula.hh"
+#include "tgba/taa.hh"
+
+namespace spot
+{
+  /// \brief Build a spot::taa* from an LTL formula.
+  ///
+  /// This is based on the following.
+  /// \verbatim
+  /// @techreport{HUT-TCS-A104,
+  ///     address = {Espoo, Finland},
+  ///     author  = {Heikki Tauriainen},
+  ///     month   = {September},
+  ///     note    = {Doctoral dissertation},
+  ///     number  = {A104},
+  ///     pages   = {xii+229},
+  ///     title   = {Automata and Linear Temporal Logic: Translations
+  ///                with Transition-Based Acceptance},
+  ///     type    = {Research Report},
+  ///     year    = {2006}
+  /// }
+  /// \endverbatim
+  ///
+  /// \param f The formula to translate into an automaton.
+  /// \param dict The spot::bdd_dict the constructed automata should use.
+  /// \return A spot::taa that recognizes the language of \a f.
+  taa* ltl_to_taa(const ltl::formula* f, bdd_dict* dict);
+}
+
+#endif /* !SPOT_TAAALGOS_LTL2TAA_HH_ */