Extend the ELTL parser to support basic aliases of automaton

operators such as F=U(true,$0) or R=!U(!$0,!$1), and infix
notation for binary automaton operators.

* README: Document the ELTL directories.
* src/eltlparse/eltlparse.yy, src/eltlparse/eltlscan.ll: Add
support for aliases and infix notation.
* src/eltlparse/public.hh, src/ltlast/nfa.cc, src/ltlast/nfa.hh:
Clean them.
* src/eltltest/acc.test, src/tgbatest/eltl2tgba.test: Add tests
for the ELTL parser's extensions.
* src/tgbatest/eltl2tgba.cc: Adjust.

ChangeLog

@@ -1,3 +1,18 @@
+2009-04-04  Damien Lefortier <dam@lrde.epita.fr>
+
+	Extend the ELTL parser to support basic aliases of automaton
+	operators such as F=U(true,$0) or R=!U(!$0,!$1), and infix
+	notation for binary automaton operators.
+
+	* README: Document the ELTL directories.
+	* src/eltlparse/eltlparse.yy, src/eltlparse/eltlscan.ll: Add
+	support for aliases and infix notation.
+	* src/eltlparse/public.hh, src/ltlast/nfa.cc, src/ltlast/nfa.hh:
+	Clean them.
+	* src/eltltest/acc.test, src/tgbatest/eltl2tgba.test: Add tests
+	for the ELTL parser's extensions.
+	* src/tgbatest/eltl2tgba.cc: Adjust.
+
 2009-03-26  Damien Lefortier <dam@lrde.epita.fr>
 
 	Add support for ELTL (AST & parser), and an adaptation of LaCIM

README

@@ -93,7 +93,7 @@ Core directories
 ----------------
 
 src/            Sources for libspot.
-   ltlast/      LTL abstract syntax tree.
+   ltlast/      LTL abstract syntax tree (including nodes for ELTL).
    ltlenv/      LTL environments.
    ltlparse/    Parser for LTL formulae.
    ltlvisit/    Visitors of LTL formulae.
@@ -105,6 +105,8 @@ src/            Sources for libspot.
    tgbaparse/   Parser for explicit TGBA.
    tgbatest/    Tests for tgba/, tgbaalgos/, and tgbaparse/.
    evtgba*/     Ignore these for now.
+   eltlparse/	Parser for ELTL formulae.
+   eltltest/    Tests for ELTL nodes in ltlast/ and eltlparse/.
 doc/	        Documentation for libspot.
    spot.html/   HTML reference manual.
    spot.latex/  Sources for the PDF manual.  (Not distributed, can be rebuilt.)

src/eltlparse/eltlparse.yy

@@ -32,29 +32,144 @@
 #include <sstream>
 #include <limits>
 #include <cerrno>
+#include <algorithm>
+#include <boost/shared_ptr.hpp>
 #include "public.hh"
 #include "ltlast/allnodes.hh"
 #include "ltlvisit/destroy.hh"
 
-// Implementation details for error handling.
 namespace spot
 {
   namespace eltl
   {
+    /// The following parser allows one to define aliases of automaton
+    /// operators such as: F=U(true,$0). Internally it's handled by
+    /// creating a small AST associated with each alias in order to
+    /// instanciate the right automatop after: U(constant(1), AP(f))
+    /// for the formula F(f).
+    ///
+    struct alias
+    {
+      virtual ~alias() {};
+    };
+    /// We use boost::shared_ptr to easily handle deletion.
+    typedef boost::shared_ptr<alias> alias_ptr;
+
+    struct alias_not : alias
+    {
+      alias_ptr s;
+    };
+    enum type { Xor, Implies, Equiv, Or, And };
+    struct alias_binary : alias
+    {
+      type ty;
+      alias_ptr lhs;
+      alias_ptr rhs;
+    };
+    struct alias_nfa : alias
+    {
+      nfa::ptr nfa;
+      std::list<alias_ptr> s;
+    };
+    struct alias_arg : alias
+    {
+      int i;
+    };
+
+    typedef std::map<std::string, nfa::ptr> nfamap;
+    typedef std::map<std::string, alias_ptr> aliasmap;
+
+    /// Implementation details for error handling.
     struct parse_error_list_t
     {
       parse_error_list list_;
       std::string file_;
     };
+
+    /// Instanciate the formula corresponding to the given alias.
+    static formula*
+    alias2formula(alias_ptr ap, spot::ltl::automatop::vec* v)
+    {
+      if (alias_not* a = dynamic_cast<alias_not*>(ap.get()))
+	return unop::instance(unop::Not, alias2formula(a->s, v));
+      if (alias_arg* a = dynamic_cast<alias_arg*>(ap.get()))
+	return a->i == -1 ? constant::true_instance() : v->at(a->i);
+      if (alias_nfa* a = dynamic_cast<alias_nfa*>(ap.get()))
+      {
+	automatop::vec* va = new automatop::vec;
+	std::list<alias_ptr>::const_iterator i = a->s.begin();
+	while (i != a->s.end())
+	  va->push_back(alias2formula(*i++, v));
+	return automatop::instance(a->nfa, va);
+      }
+      /// TODO.
+      assert(0);
+    }
+
+    /// Get the arity of a given alias.
+    static size_t
+    arity(alias_ptr ap)
+    {
+      if (alias_not* a = dynamic_cast<alias_not*>(ap.get()))
+	return arity(a->s);
+      if (alias_arg* a = dynamic_cast<alias_arg*>(ap.get()))
+	return a->i + 1;
+      if (alias_nfa* a = dynamic_cast<alias_nfa*>(ap.get()))
+      {
+	size_t res = 0;
+	std::list<alias_ptr>::const_iterator i = a->s.begin();
+	while (i != a->s.end())
+	  res = std::max(arity(*i++), res);
+	return res;
+      }
+      /// TODO.
+      assert(0);
+    }
   }
 }
 
 #define PARSE_ERROR(Loc, Msg)			\
   pe.list_.push_back				\
     (parse_error(Loc, spair(pe.file_, Msg)))
+
+#define CHECK_EXISTING_NMAP(Loc, Ident)			\
+  {							\
+    nfamap::iterator i = nmap.find(*Ident);		\
+    if (i == nmap.end())				\
+    {							\
+      std::string s = "unknown automaton operator `";	\
+      s += *Ident;					\
+      s += "'";						\
+      PARSE_ERROR(Loc, s);				\
+      delete Ident;					\
+      YYERROR;						\
+    }							\
+  }
+
+#define CHECK_ARITY(Loc, Ident, A1, A2)			\
+  {							\
+    if (A1 != A2)					\
+    {							\
+      std::ostringstream oss1;				\
+      oss1 << A1;					\
+      std::ostringstream oss2;				\
+      oss2 << A2;					\
+							\
+      std::string s(*Ident);				\
+      s += " is used with ";				\
+      s += oss1.str();					\
+      s += " arguments, but has an arity of ";		\
+      s += oss2.str();					\
+      PARSE_ERROR(Loc, s);				\
+      delete Ident;					\
+      YYERROR;						\
+    }							\
+  }
+
 }
 
 %parse-param {spot::eltl::nfamap& nmap}
+%parse-param {spot::eltl::aliasmap& amap}
 %parse-param {spot::eltl::parse_error_list_t &pe}
 %parse-param {spot::ltl::environment &parse_environment}
 %parse-param {spot::ltl::formula* &result}
@@ -68,6 +183,10 @@ namespace spot
   spot::ltl::nfa* nval;
   spot::ltl::automatop::vec* aval;
   spot::ltl::formula* fval;
+
+  /// To handle aliases.
+  spot::eltl::alias* pval;
+  spot::eltl::alias_nfa* bval;
 }
 
 %code {
@@ -104,17 +223,22 @@ using namespace spot::ltl;
 
 /* Priorities.  */
 
-/* Logical operators.  */
 %left OP_OR
 %left OP_XOR
 %left OP_AND
 %left OP_IMPLIES OP_EQUIV
 
+%left ATOMIC_PROP
+
 %nonassoc OP_NOT
 
 %type <nval> nfa_def
 %type <fval> subformula
 %type <aval> arg_list
+%type <ival> nfa_arg
+%type <pval> nfa_alias
+%type <pval> nfa_alias_arg
+%type <bval> nfa_alias_arg_list
 
 %destructor { delete $$; } "atomic proposition"
 %destructor { spot::ltl::destroy($$); } subformula
@@ -132,7 +256,7 @@ result: nfa_list subformula
 
 /* NFA definitions. */
 
-nfa_list: /* empty. */
+nfa_list: /* empty */
         | nfa_list nfa
 ;
 
@@ -142,28 +266,22 @@ nfa: IDENT "=" "(" nfa_def ")"
           nmap[*$1] = nfa::ptr($4);
 	  delete $1;
         }
+   | IDENT "=" nfa_alias
+        {
+	  amap[*$1] = alias_ptr($3);
+   	  delete $1;
+   	}
 ;
 
-nfa_def: /* empty. */
+nfa_def: /* empty */
         {
 	  $$ = new nfa();
         }
-        | nfa_def STATE STATE ARG
+        | nfa_def STATE STATE nfa_arg
         {
-	  if ($4 == -1 || $3 == -1 || $2 == -1)
-	  {
-	    std::string s = "out of range integer";
-	    PARSE_ERROR(@1, s);
-	    YYERROR;
-	  }
 	  $1->add_transition($2, $3, $4);
 	  $$ = $1;
         }
-        | nfa_def STATE STATE CONST_TRUE
-        {
-	  $1->add_transition($2, $3, -1);
-	  $$ = $1;
-	}
         | nfa_def ACC STATE
         {
  	  $1->set_final($3);
@@ -171,6 +289,71 @@ nfa_def: /* empty. */
         }
 ;
 
+nfa_alias: IDENT "(" nfa_alias_arg_list ")"
+	{
+	  aliasmap::iterator i = amap.find(*$1);
+	  if (i != amap.end())
+	    assert(0); // FIXME
+	  else
+	  {
+	    CHECK_EXISTING_NMAP(@1, $1);
+	    nfa::ptr np = nmap[*$1];
+
+	    CHECK_ARITY(@1, $1, $3->s.size(), np->arity());
+	    $3->nfa = np;
+	    $$ = $3;
+	  }
+	  delete $1;
+	}
+	| OP_NOT nfa_alias
+	{
+	  alias_not* a = new alias_not;
+	  a->s = alias_ptr($2);
+	  $$ = a;
+	}
+	// TODO: more complicated aliases like | IDENT "(" nfa_alias ")"
+
+nfa_alias_arg_list: nfa_alias_arg
+	{
+	  $$ = new alias_nfa;
+	  $$->s.push_back(alias_ptr($1));
+	}
+	| nfa_alias_arg_list "," nfa_alias_arg
+	{
+	  $1->s.push_back(alias_ptr($3));
+	  $$ = $1;
+	}
+;
+
+nfa_alias_arg: nfa_arg
+	{
+	  alias_arg* a = new alias_arg;
+	  a->i = $1;
+	  $$ = a;
+	}
+	| OP_NOT nfa_alias_arg
+	{
+	  alias_not* a = new alias_not;
+	  a->s = alias_ptr($2);
+	  $$ = a;
+	}
+	// TODO
+
+nfa_arg: ARG
+	{
+	  if ($1 == -1)
+	  {
+	    std::string s = "out of range integer";
+	    PARSE_ERROR(@1, s);
+	    YYERROR;
+	  }
+	  $$ = $1;
+	}
+	| CONST_TRUE
+	{ $$ = -1; }
+;
+
+
 /* Formulae. */
 
 subformula: ATOMIC_PROP
@@ -189,40 +372,50 @@ subformula: ATOMIC_PROP
 	   }
 	   else
 	     delete $1;
+	}
+	  | subformula ATOMIC_PROP subformula
+	{
+	  aliasmap::iterator i = amap.find(*$2);
+	  if (i != amap.end())
+	  {
+	    CHECK_ARITY(@1, $2, 2, arity(i->second));
+	    automatop::vec* v = new automatop::vec;
+	    v->push_back($1);
+	    v->push_back($3);
+	    $$ = alias2formula(i->second, v);
+	    delete v;
+	  }
+	  else
+	  {
+	    CHECK_EXISTING_NMAP(@1, $2);
+	    nfa::ptr np = nmap[*$2];
+
+	    CHECK_ARITY(@1, $2, 2, np->arity());
+	    automatop::vec* v = new automatop::vec;
+	    v->push_back($1);
+	    v->push_back($3);
+	    $$ = automatop::instance(np, v);
+	  }
+	  delete $2;
 	}
 	  | ATOMIC_PROP "(" arg_list ")"
 	{
-	  nfamap::iterator i = nmap.find(*$1);
+	  aliasmap::iterator i = amap.find(*$1);
-	  if (i == nmap.end())
+	  if (i != amap.end())
 	  {
-	    std::string s = "unknown automaton operator `";
+	    CHECK_ARITY(@1, $1, $3->size(), arity(i->second));
-	    s += *$1;
+	    $$ = alias2formula(i->second, $3);
-	    s += "'";
-	    PARSE_ERROR(@1, s);
-	    delete $1;
-	    YYERROR;
-	  }
-
-	  automatop* res = automatop::instance(i->second, $3);
-	  if (res->size() != i->second->arity())
-	  {
-	    std::ostringstream oss1;
-	    oss1 << res->size();
-	    std::ostringstream oss2;
-	    oss2 << i->second->arity();
-
-	    std::string s(*$1);
-	    s += " is used with ";
-	    s += oss1.str();
-	    s += " arguments, but has an arity of ";
-	    s += oss2.str();
-	    PARSE_ERROR(@1, s);
-	    delete $1;
 	    delete $3;
-	    YYERROR;
+	  }
+	  else
+	  {
+	    CHECK_EXISTING_NMAP(@1, $1);
+	    nfa::ptr np = nmap[*$1];
+
+	    CHECK_ARITY(@1, $1, $3->size(), np->arity());
+	    $$ = automatop::instance(np, $3);
 	  }
 	  delete $1;
-	  $$ = res;
 	}
 	  | CONST_TRUE
 	{ $$ = constant::true_instance(); }
@@ -284,9 +477,10 @@ namespace spot
       }
       formula* result = 0;
       nfamap nmap;
+      aliasmap amap;
       parse_error_list_t pe;
       pe.file_ = name;
-      eltlyy::parser parser(nmap, pe, env, result);
+      eltlyy::parser parser(nmap, amap, pe, env, result);
       parser.set_debug_level(debug);
       parser.parse();
       error_list = pe.list_;
@@ -303,8 +497,9 @@ namespace spot
       flex_scan_string(eltl_string.c_str());
       formula* result = 0;
       nfamap nmap;
+      aliasmap amap;
       parse_error_list_t pe;
-      eltlyy::parser parser(nmap, pe, env, result);
+      eltlyy::parser parser(nmap, amap, pe, env, result);
       parser.set_debug_level(debug);
       parser.parse();
       error_list = pe.list_;

src/eltlparse/eltlscan.ll

@@ -58,18 +58,53 @@ eol      \n|\r|\n\r|\r\n
   yylloc->step();
 %}
 
+  /* Rules for the include part. */
+
+<incl>[ \t]*
+<incl>[^ \t\n]+		{
+			  FILE* tmp = fopen(yytext, "r");
+			  if (!tmp)
+			    ERROR(std::string("cannot open file ") + yytext);
+			  else
+			  {
+			    include.push(make_pair(YY_CURRENT_BUFFER, pe.file_));
+                            pe.file_ = std::string(yytext);
+			    yy_switch_to_buffer(yy_create_buffer(tmp, YY_BUF_SIZE));
+                          }
+			  BEGIN(INITIAL);
+			}
+
+  /* Global rules (1). */
+
+"("			return token::LPAREN;
+","			return token::COMMA;
+")"			return token::RPAREN;
+"!"			return token::OP_NOT;
+
+  /* & and | come from Spin.  && and || from LTL2BA.
+     /\, \/, and xor are from LBTT.
+  */
+"||"|"|"|"+"|"\\/" {
+			  return token::OP_OR;
+			}
+"&&"|"&"|"."|"*"|"/\\"	{
+			  return token::OP_AND;
+			}
+"^"|"xor"		return token::OP_XOR;
+"=>"|"->"		return token::OP_IMPLIES;
+"<=>"|"<->"		return token::OP_EQUIV;
+
   /* Rules for the automaton definitions part. */
 
+<INITIAL>"include"	BEGIN(incl);
+<INITIAL>"%"		BEGIN(formula);
+
 <INITIAL>"="		return token::EQ;
 <IINTIAL>"accept"	return token::ACC;
+
 <INITIAL>[tT][rR][uU][eE] {
 			  return token::CONST_TRUE;
 			}
-<INITIAL>"("		return token::LPAREN;
-<INITIAL>")"		return token::RPAREN;
-<INITIAL>"%"		BEGIN(formula);
-
-<INITIAL>"include"	BEGIN(incl);
 
 <INITIAL>[a-zA-Z][a-zA-Z0-9_]* {
 			  yylval->sval = new std::string(yytext, yyleng);
@@ -99,30 +134,8 @@ eol      \n|\r|\n\r|\r\n
 			  yy_switch_to_buffer(s.first);
 			}
 
-  /* Rules for the include part. */
-
-<incl>[ \t]*
-<incl>[^ \t\n]+		{
-			  FILE* tmp = fopen(yytext, "r");
-			  if (!tmp)
-			    ERROR(std::string("cannot open file ") + yytext);
-			  else
-			  {
-			    include.push(make_pair(YY_CURRENT_BUFFER, pe.file_));
-                            pe.file_ = std::string(yytext);
-			    yy_switch_to_buffer(yy_create_buffer(tmp, YY_BUF_SIZE));
-                          }
-			  BEGIN(INITIAL);
-			}
-
   /* Rules for the formula part. */
 
-<formula>"("		return token::LPAREN;
-<formula>")"		return token::RPAREN;
-<formula>"!"		return token::OP_NOT;
-<formula>","		return token::COMMA;
-
-
 <formula>"1"|[tT][rR][uU][eE] {
 			  return token::CONST_TRUE;
 			}
@@ -130,25 +143,12 @@ eol      \n|\r|\n\r|\r\n
 			  return token::CONST_FALSE;
 			}
 
-  /* & and | come from Spin.  && and || from LTL2BA.
-     /\, \/, and xor are from LBTT.
-  */
-<formula>"||"|"|"|"+"|"\\/" {
-			  return token::OP_OR;
-			}
-<formula>"&&"|"&"|"."|"*"|"/\\"	{
-			  return token::OP_AND;
-			}
-<formula>"^"|"xor"	return token::OP_XOR;
-<formula>"=>"|"->"	return token::OP_IMPLIES;
-<formula>"<=>"|"<->"	return token::OP_EQUIV;
-
 <formula>[a-zA-Z][a-zA-Z0-9_]* {
 			  yylval->sval = new std::string(yytext, yyleng);
 			  return token::ATOMIC_PROP;
 			}
 
-  /* Global rules. */
+  /* Global rules (2). */
 
 			/* discard whitespace */
 {eol}			yylloc->lines(yyleng); yylloc->step();

src/eltlparse/public.hh

@@ -35,6 +35,11 @@
 # include <utility>
 # include <iosfwd>
 
+// namespace
+// {
+//   typedef std::map<std::string, spot::ltl::nfa::ptr> nfamap;
+// }
+
 namespace spot
 {
   using namespace ltl;
@@ -50,9 +55,6 @@ namespace spot
     /// \brief A list of parser diagnostics, as filled by parse.
     typedef std::list<parse_error> parse_error_list;
 
-    ///
-    typedef std::map<std::string, nfa::ptr> nfamap;
-
     /// \brief Build a formula from a text file.
     /// \param name The name of the file to parse.
     /// \param error_list A list that will be filled with

src/eltltest/acc.test

@@ -33,7 +33,24 @@ U=(
     0 1 \$1
     accept 1
   )
+F=U(true, \$0)
+R=!U(!\$0, !\$1)
+%
+a U b | a R b | F(true) | U(a,b) -> R(a,b)
 EOF
+run 0 ./acc input || exit 1
+
+cat >input <<EOF
+U=(
+    0 0 \$0
+    0 1 \$1
+    accept 1
+  )
+T=U(true,true)
+%
+T()|1
+EOF
+run 1 ./acc input || exit 1
 
 cat >input <<EOF
 A=(

src/ltlast/nfa.cc

@@ -27,7 +27,7 @@ namespace spot
   namespace ltl
   {
     nfa::nfa()
-      : is_(), si_(), arity_(0), name_(), init_(0), finals_()
+      : is_(), si_(), arity_(-1), name_(), init_(0), finals_()
     {
     }
 

src/ltlast/nfa.hh

@@ -102,7 +102,7 @@ namespace spot
       si_map si_;
 
       int arity_;
-      std::string name_; // FIXME.
+      std::string name_;
 
       state* init_;
       std::set<int> finals_;

src/tgbatest/eltl2tgba.cc

@@ -51,7 +51,9 @@ X=(0 1 true	   \
 U=(0 0 $0	   \
    0 1 $1	   \
    accept 1)	   \
-G=(0 0 $0)";
+G=(0 0 $0)	   \
+F=U(true, $0)	   \
+R=!U(!$0, !$1)";
   return s;
 }
 

src/tgbatest/eltl2tgba.test

@@ -36,6 +36,8 @@ U=(
 G=(
     0 0 \$0
   )
+F=U(true, \$0)
+R=!U(!\$0, !\$1)
 EOF
 
 cat >input <<EOF
@@ -51,7 +53,7 @@ check_true 'Ga'
 cat >input <<EOF
 include input1
 %
-U(a,b)
+a U b
 EOF
 
 check_construct input
@@ -62,7 +64,7 @@ check_false 'G(a&!b)'
 cat >input <<EOF
 include input1
 %
-!U(a,b)
+!(a U b)
 EOF
 
 check_construct input
@@ -102,6 +104,26 @@ check_construct input
 check_true 'Ga'
 check_false '!Ga'
 
+cat >input <<EOF
+include input1
+%
+F(a)
+EOF
+
+check_construct input
+check_true 'Fa'
+check_false '!Fa'
+
+cat >input <<EOF
+include input1
+%
+a R b
+EOF
+
+check_construct input
+check_true 'a R b'
+check_false '!(a R b)'
+
 cat >input <<EOF
 T=(
     0 1 true