* src/tgbaalgos/bfssteps.hh, src/tgbaalgos/bfssteps.cc: New files.

* src/tgbaalgos/Makefile.am (tgbaalgos_HEADERS,
libtgbaalgos_la_SOURCES): Add them.
* src/tgbaalgos/gv04.cc (gv04::result::accepting_run): Use
the new bfs_steps class.

src/tgbaalgos/bfssteps.hh

@@ -0,0 +1,43 @@
+// Copyright (C) 2004  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_TGBAALGOS_BFSSTEPS_HH
+# define SPOT_TGBAALGOS_BFSSTEPS_HH
+
+#include "emptiness.hh"
+
+namespace spot
+{
+  class bfs_steps
+  {
+  public:
+    bfs_steps(const tgba* a);
+    virtual ~bfs_steps();
+    const state* search(const state* start, tgba_run::steps& l);
+    virtual const state* filter(const state* s) = 0;
+    virtual bool match(tgba_run::step& step, const state* dest) = 0;
+  protected:
+    const tgba* a_;
+  };
+
+}
+
+#endif // SPOT_TGBAALGOS_BFSSTEPS_HH