Implement W,M removal for Spin output.

* src/ltlvisit/wmunabbrev.hh, src/ltlvisit/wmunabbrev.cc: New files.
* src/ltlvisit/Makefile.am: Add them.
* src/ltlvisit/tostring.cc (to_spin_string): Use the new rewriting.
* wrap/python/ajax/spot.in: Warn when a "Spin" still contain PSL
operators.
* wrap/python/ajax/ltl2tgba.html: Adjust help text.
* doc/tl/tl.tex, NEWS: Document the new rewriting.

src/ltlvisit/Makefile.am

@@ -45,7 +45,8 @@ ltlvisit_HEADERS = \
   simplify.hh \
   snf.hh \
   tostring.hh \
-  tunabbrev.hh
+  tunabbrev.hh \
+  wmunabbrev.hh
 
 noinst_LTLIBRARIES = libltlvisit.la
 libltlvisit_la_SOURCES = \
@@ -66,4 +67,5 @@ libltlvisit_la_SOURCES = \
   simplify.cc \
   snf.cc \
   tostring.cc \
-  tunabbrev.cc
+  tunabbrev.cc \
+  wmunabbrev.cc

src/ltlvisit/tostring.cc

@@ -30,6 +30,7 @@
 #include "ltlast/allnodes.hh"
 #include "ltlast/visitor.hh"
 #include "lunabbrev.hh"
+#include "wmunabbrev.hh"
 #include "tostring.hh"
 
 
@@ -108,8 +109,8 @@ namespace spot
 	" <-> ",		// rewritten
 	" U ",
 	" V ",
-	" W ",			// not supported
-	" M ",			// not supported
+	" W ",			// rewritten
+	" M ",			// rewritten
 	"<>-> ",		// not supported
 	"<>=> ",		// not supported
 	"<>+> ",		// not supported
@@ -754,9 +755,12 @@ namespace spot
     {
       // Remove xor, ->, and <-> first.
       formula* fu = unabbreviate_logic(f);
-      to_string_visitor v(os, full_parent, false, spin_kw);
-      fu->accept(v);
+      // Also remove W and M.
+      f = unabbreviate_wm(fu);
       fu->destroy();
+      to_string_visitor v(os, full_parent, false, spin_kw);
+      f->accept(v);
+      f->destroy();
       return os;
     }
 

src/ltlvisit/wmunabbrev.cc

@@ -0,0 +1,96 @@
+// -*- coding: utf-8 -*-
+// Copyright (C) 2012 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 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.
+
+#include "ltlast/allnodes.hh"
+#include "clone.hh"
+#include "wmunabbrev.hh"
+#include <cassert>
+
+namespace spot
+{
+  namespace ltl
+  {
+    namespace
+    {
+      class unabbreviate_wm_visitor : public clone_visitor
+      {
+	typedef clone_visitor super;
+      public:
+	unabbreviate_wm_visitor()
+	{
+	}
+
+	virtual
+	~unabbreviate_wm_visitor()
+	{
+	}
+
+	using super::visit;
+	void visit(binop* bo)
+	{
+	  formula* f1 = recurse(bo->first());
+	  formula* f2 = recurse(bo->second());
+	  binop::type op = bo->op();
+	  switch (op)
+	    {
+	    case binop::Xor:
+	    case binop::Implies:
+	    case binop::Equiv:
+	    case binop::U:
+	    case binop::R:
+	    case binop::UConcat:
+	    case binop::EConcat:
+	    case binop::EConcatMarked:
+	      result_ = binop::instance(op, f1, f2);
+	      break;
+	    case binop::W:
+	      // f1 W f2 = f2 R (f2 | f1)
+	      result_ =
+		binop::instance(binop::R, f2->clone(),
+				multop::instance(multop::Or, f2, f1));
+	      break;
+	    case binop::M:
+	      // f1 M f2 = f2 U (g2 & f1)
+	      result_ =
+		binop::instance(binop::U, f2->clone(),
+				multop::instance(multop::And, f2, f1));
+	      break;
+	    }
+	}
+
+	virtual formula* recurse(formula* f)
+	{
+	  if (f->is_boolean())
+	    return f->clone();
+	  f->accept(*this);
+	  return this->result();
+	}
+      };
+    }
+
+    formula*
+    unabbreviate_wm(const formula* f)
+    {
+      unabbreviate_wm_visitor v;
+      return v.recurse(const_cast<formula*>(f));
+    }
+  }
+}

src/ltlvisit/wmunabbrev.hh

@@ -0,0 +1,44 @@
+// -*- coding: utf-8 -*-
+// Copyright (C) 2012 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 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_LTLVISIT_WMUNABBREV_HH
+# define SPOT_LTLVISIT_WMUNABBREV_HH
+
+namespace spot
+{
+  namespace ltl
+  {
+    class formula;
+
+    /// \brief Rewrite a formula to remove the W and M operators.
+    ///
+    /// This is necessary if you want to use the formula with a tool
+    /// that do not support these operators.
+    ///
+    /// <code>a W b</code> is replaced by <code>b R (b | a)</code>,
+    /// and <code>a M b</code> is replaced by <code>b U (b & a)</code>.
+    ///
+    /// \ingroup ltl_rewriting
+    formula* unabbreviate_wm(const formula* f);
+  }
+}
+
+#endif // SPOT_LTLVISIT_WMUNABBREV_HH