Add support for [+].

* src/ltlast/bunop.cc (bunop::format): Output [*1..] as [+].
* src/ltlvisit/tostring.cc: Output "a*" as "a[*]" for consistency.
* src/ltlparse/ltlparse.yy, src/ltlparse/ltlscan.ll: Recognize [+].
* src/ltltest/tostring.test, src/ltltest/equals.test,
src/tgbatest/ltl2tgba.test: More tests.

src/ltlast/bunop.cc

@@ -119,6 +119,14 @@ namespace spot
     bunop::format() const
     {
       std::ostringstream out;
+
+      // Syntactic sugaring
+      if (min_ == 1 && max_ == unbounded)
+	{
+	  out << "[+]";
+	  return out.str();
+	}
+
       out << "[*";
       if (min_ != 0 || max_ != unbounded)
 	{

src/ltlparse/ltlparse.yy

@@ -90,6 +90,7 @@ using namespace spot::ltl;
 %token OP_W "weak until operator" OP_M "strong release operator"
 %token OP_F "sometimes operator" OP_G "always operator"
 %token OP_X "next operator" OP_NOT "not operator" OP_STAR "star operator"
+%token OP_PLUS "plus operator"
 %token OP_STAR_OPEN "opening bracket for star operator"
 %token OP_STAR_CLOSE "closing bracket for star operator"
 %token <num> OP_STAR_NUM "number for star operator"
@@ -123,7 +124,7 @@ using namespace spot::ltl;
 %nonassoc OP_X
 
 /* High priority regex operator. */
-%nonassoc OP_STAR OP_STAR_OPEN
+%nonassoc OP_STAR OP_STAR_OPEN OP_PLUS
 
 /* Not has the most important priority after Wring's `=0' and `=1'.  */
 %nonassoc OP_NOT
@@ -191,6 +192,8 @@ error_opt: | error
 
 starargs: OP_STAR
             { $$.min = 0U; $$.max = bunop::unbounded; }
+        | OP_PLUS
+	    { $$.min = 1U; $$.max = bunop::unbounded; }
 	| OP_STAR_OPEN OP_STAR_NUM OP_STAR_SEP OP_STAR_NUM OP_STAR_CLOSE
             { $$.min = $2; $$.max = $4; }
 	| OP_STAR_OPEN OP_STAR_NUM OP_STAR_SEP OP_STAR_CLOSE
@@ -200,7 +203,7 @@ starargs: OP_STAR
 	| OP_STAR_OPEN OP_STAR_SEP_opt OP_STAR_CLOSE
             { $$.min = 0U; $$.max = bunop::unbounded; }
 	| OP_STAR_OPEN OP_STAR_NUM OP_STAR_CLOSE
-            { $$.min = $2; $$.max = $2; }
+            { $$.min = $$.max = $2; }
 	| OP_STAR_OPEN error OP_STAR_CLOSE
             { error_list.push_back(parse_error(@$,
 	        "treating this star block as [*]"));

src/ltlparse/ltlscan.ll

@@ -95,6 +95,7 @@ flex_set_buffer(const char* buf, int start_tok)
 ";"				BEGIN(0); return token::OP_CONCAT;
 ":"				BEGIN(0); return token::OP_FUSION;
 "*"|"[*]"			BEGIN(0); return token::OP_STAR;
+"[+]"				BEGIN(0); return token::OP_PLUS;
 "[*"				BEGIN(star); return token::OP_STAR_OPEN;
 <star>"]"			BEGIN(0); return token::OP_STAR_CLOSE;
 <star>[0-9]+			{

src/ltltest/equals.test

@@ -134,3 +134,8 @@ run 0 ../equals '{a[*..3][*2]}' '{a[*..6]}'
 run 0 ../equals '{a[*..3][*..2]}' '{a[*..6]}'
 run 0 ../equals '{a[*..3][*2..]}' '{a[*]}'
 run 0 ../equals '{a[*..3][*2..]}' '{a[*]}'
+run 0 ../equals '{a[*1..]}' '{a[+]}'
+run 0 ../equals '{a[+][*1..3]}' '{a[+]}'
+run 0 ../equals '{a[*1..3][+]}' '{a[+]}'
+run 0 ../equals '{[*2][+]}' '{[*2][+]}'
+run 0 ../equals '{[+][*2]}' '{[*2..]}'

src/ltltest/tostring.test

@@ -66,4 +66,6 @@ run 0 ../tostring '{a[*0..1]}'
 run 0 ../tostring '{a[*0..]}'
 run 0 ../tostring '{a[*..]}'
 run 0 ../tostring '{a[*1..]}'
+run 0 ../tostring '{a[+]}'
+run 0 ../tostring '{[+]}'
 run 0 ../tostring '{a[*2..3][*4..5]}'

src/ltlvisit/tostring.cc

@@ -1,4 +1,4 @@
-// Copyright (C) 2008, 2010, 2011 Laboratoire de Recherche et Développement
+// Copyright (C) 2008, 2010, 2011 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
@@ -182,12 +182,12 @@ namespace spot
 	void
 	visit(const bunop* bo)
 	{
-	  // Abbreviate "1*" as "*".
+	  // Abbreviate "1[*]" as "[*]".
 	  if (bo->child() != constant::true_instance())
 	    {
-	      // a* is OK, no need to print {a}*.
+	      // a[*] is OK, no need to print {a}[*].
-	      // However want braces for {!a}*, the only unary
+	      // However want braces for {!a}[*], the only unary
-	      // operator that can be nested with *.
+	      // operator that can be nested with [*].
 	      bool need_parent = !!dynamic_cast<const unop*>(bo->child());
 
 	      if (need_parent || full_parent_)
@@ -197,10 +197,6 @@ namespace spot
 		closep();
 	    }
 
-	  // Output "*" instead of "[*]".
-	  if (bo->min() == 0 && bo->max() == bunop::unbounded)
-	    os_ << "*";
-	  else
 	  os_ << bo->format();
 	}
 

src/tgbatest/ltl2tgba.test

@@ -83,6 +83,7 @@ check_psl '{((!c;b*) & d);e}'
 check_psl '{(a* & (c;b*) & d);e}'
 check_psl '{[*2];a[*2..4]}|->b'
 check_psl '{a[*2..5] && b[*..3]}|->c'
+check_psl '{{[+];a;[+]} && {[+];b;[+]}}<>->c'
 # Example from "Beyond Hardware Verification" by Glazberg, Moulin, Orni,
 # Ruah, Zarpas (2007).
 check_psl '{[*];req;ack}|=>{start;busy[*];done}'