ltlparse: Add compatibility with ltl2dsar's input.

* src/ltlparse/ltlscan.ll: Accept as a proposition any
alphanumeric string that is not an operator.
* NEWS: Mention it.
* src/ltltest/lbt.test: New file.  Also tests previous patch.
* src/ltltest/Makefile.am: Add it.

NEWS

@@ -27,6 +27,10 @@ New in spot 1.0a (not released):
       transition counts, just as the ltlcross tool.
     - ltlcross will display the number of timeouts at the end
       of its execution.
+    - The parser for LBT's prefix-style LTL formulas will now
+      read atomic propositions that are not of the form p1, p2...
+      This makes it possible to process formulas written in
+      ltl2dstar's syntax.
   * Pruning:
     - lbtt has been removed from the distribution.  A copy of the last
       version we distributed is still available at

src/ltlparse/ltlscan.ll

@@ -1,4 +1,5 @@
-/* Copyright (C) 2010, 2011, 2012, Laboratoire de Recherche et
+/* -*- coding: utf-8 -*-
+** Copyright (C) 2010, 2011, 2012, 2013, Laboratoire de Recherche et
 ** Développement de l'Epita (LRDE).
 ** Copyright (C) 2003, 2004  Laboratoire d'Informatique de Paris 6 (LIP6),
 ** département Systèmes Répartis Coopératifs (SRC), Université Pierre
@@ -87,7 +88,10 @@ BOXDARROW {BOX}{DARROWL}|"|"{DARROWL}|"⤇"
 				  yylval->str = new std::string();
                                 }
 <in_par>{
-	 "("			++parent_level; yylval->str->append(yytext, yyleng);
+	 "("			{
+				  ++parent_level;
+				  yylval->str->append(yytext, yyleng);
+				}
 	 ")"			{
 				  if (--parent_level)
 				    {
@@ -126,7 +130,10 @@ BOXDARROW {BOX}{DARROWL}|"|"{DARROWL}|"⤇"
 				  yylval->str = new std::string();
                                 }
 <in_bra>{
-	 "{"			++parent_level; yylval->str->append(yytext, yyleng);
+	 "{"			{
+				  ++parent_level;
+				  yylval->str->append(yytext, yyleng);
+				}
          "}"[ \t\n]*"!"         {
 				  if (--parent_level)
 				    {
@@ -281,11 +288,16 @@ BOXDARROW {BOX}{DARROWL}|"|"{DARROWL}|"⤇"
 			  return token::ATOMIC_PROP;
 			}
 
-  /* in LBT's format, atomic proposition look like p0 or p3141592 */
+  /* these are operators */
-<lbt>p[0-9]+            {
+<lbt>[eitfXFGUVRWM]	return *yytext;
+  /* in LBT's format, atomic proposition look like p0 or p3141592, but
+     for compatibility with ltl2dstar we also accept any alphanumeric
+     string that is not an operator. */
+<lbt>[a-zA-Z._][a-zA-Z0-9._]*            {
 			  yylval->str = new std::string(yytext, yyleng);
 			  return token::ATOMIC_PROP;
 			}
+
   /* Atomic propositions can also be enclosed in double quotes.  */
 <lbt>\"[^\"]*\"		{
 			  yylval->str = new std::string(yytext + 1,

src/ltltest/Makefile.am

@@ -1,4 +1,4 @@
-## Copyright (C) 2009, 2010, 2011, 2012 Laboratoire de Recherche et
+## Copyright (C) 2009, 2010, 2011, 2012, 2013 Laboratoire de Recherche et
 ## Développement de l'Epita (LRDE).
 ## Copyright (C) 2003, 2004, 2005, 2006 Laboratoire d'Informatique de
 ## Paris 6 (LIP6), département Systèmes Répartis Coopératifs (SRC),
@@ -90,6 +90,7 @@ TESTS = \
   unabbrevwm.test \
   consterm.test \
   kind.test \
+  lbt.test \
   lenient.test \
   syntimpl.test \
   reduc.test \

src/ltltest/lbt.test

@@ -0,0 +1,107 @@
+#!/bin/sh
+# -*- 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/>.
+
+. ./defs
+
+ltlfilt=../../bin/ltlfilt
+randltl=../../bin/randltl
+genltl=../../bin/genltl
+
+# Some example formulas taken from Ruediger Ehlers's dbaminimizer
+#   http://react.cs.uni-saarland.de/tools/dbaminimizer
+# which are expected to be processed by ltl2dstar.
+cat >formulas <<'EOF'
+& G F a G F b
+X X a
+G F e a X X b
+G F e a X X X b
+G i a X X X b
+G F i a X X X b
+& G i a F b G i b F c
+G i a F b
+& G i a F b G c
+& & G ! c G i a F b G i b F c
+& G i a F b G i c F d
+& i G a F b i G ! a F ! b
+& G i a F b G i ! a F ! b
+U p & q X U r s
+U p & q X & r F & s X F & u X F & v X F w
+F & p X & q X F r
+F & q X U p r
+G i p U q r
+F & p X F & q X F & r X F s
+& & & & G F p G F q G F r G F s G F u
+| | U p U q r U q U r p U r U p q
+| | G F a G F b G F c
+G F a
+U a U b U c d
+G U a U b U ! a ! b
+EOF
+
+# More examples taken from scheck's test suite.
+#   http://tcs.legacy.ics.tkk.fi/users/tlatvala/scheck/
+cat >>formulas <<EOF
+| F X p1 F X p2
+ | | X p7 F p6 & | | t p3 p7 U | f p3 p3
+F p99
+X p3
+X ! p3
+X t
+X X X p3
+F X X X t
+! G p5
+| X p0 F p5
+| F p2 F p9
+! | G p0 & G p1 F p3
+& U & X p0 X p4 F p1 X X U X F p5 U p0 X X p3
+| p3 p5
+& p1 p6
+| p1 | p2 p1
+| & p1 p3 p3
+p6
+U p1 ! p2
+| p5 U p2 p2
+& p5 U p2 p2
+U F p5 ! p1
+U p0 & | p0 p5 p1
+EOF
+
+# More examples randomly generated
+$randltl -l -n 100 a p1 "X" "U" "U12" >> formulas
+
+# Some examples from scalables formulas
+$genltl --rv-counter=1..10 --go-theta=1..10 -l >> formulas
+
+count=`wc -l < formulas`
+
+test $count -eq 168
+
+run 0 $ltlfilt --lbt-input formulas > formulas.2
+run 0 $ltlfilt -l formulas.2 > formulas.3
+run 0 $ltlfilt -l --lbt-input formulas > formulas.4
+test `wc -l < formulas.2` -eq 168
+test `wc -l < formulas.3` -eq 168
+test `wc -l < formulas.4` -eq 168
+
+
+# Make sure ltl2dstar-style litterals always get quoted.
+test "`$ltlfilt -l --lbt-input -f 'G F a'`" = 'G F "a"'
+# Original lbt-style litterals are unquoted.
+test "`$ltlfilt -l --lbt-input -f 'G F p42'`" = 'G F p42'