hoa: make it possible to read a stream of automata

* src/bin/autfilt.cc: Loop over all automata in a file.
* src/hoaparse/public.hh: Turn the parser into an object.
* src/hoaparse/hoaparse.yy: Adjust.

src/bin/autfilt.cc

@@ -292,17 +292,10 @@ namespace
       SPOT_UNREACHABLE();
     }
 
-
     int
-    process_file(const char* filename)
+    process_automaton(const spot::const_hoa_aut_ptr& haut,
+		      const char* filename)
     {
-      spot::hoa_parse_error_list pel;
-      auto haut = spot::hoa_parse(filename, pel, spot::make_bdd_dict());
-      if (spot::format_hoa_parse_errors(std::cerr, filename, pel))
-	return 2;
-      if (!haut)
-	error(2, 0, "failed to read automaton from %s", filename);
-
       spot::stopwatch sw;
       sw.start();
       auto aut = post.run(haut->aut, nullptr);
@@ -337,6 +330,32 @@ namespace
       flush_cout();
       return 0;
     }
+
+
+    int
+    process_file(const char* filename)
+    {
+      spot::hoa_parse_error_list pel;
+      auto b = spot::make_bdd_dict();
+      auto hp = spot::hoa_stream_parser(filename);
+
+      int err = 0;
+
+      for (;;)
+	{
+	  auto haut = hp.parse(pel, b);
+	  if (!haut && pel.empty())
+	    break;
+	  if (spot::format_hoa_parse_errors(std::cerr, filename, pel))
+	    err = 2;
+	  if (!haut)
+	    error(0, 0, "failed to read automaton from %s", filename);
+	  else
+	    process_automaton(haut, filename);
+	}
+
+      return err;
+    }
   };
 }
 

src/hoaparse/hoaparse.yy

@@ -95,6 +95,7 @@
 %token <str> ANAME "alias name";
 %token <str> STRING "string";
 %token <num> INT "integer";
+%token ENDOFFILE 0 "end of file"
 
 %left '|'
 %left '&'
@@ -114,7 +115,8 @@
 %printer { debug_stream() << $$; } <num>
 
 %%
-hoa: header "--BODY--" body "--END--"
+hoa: header "--BODY--" body "--END--" { YYACCEPT; }
+hoa: ENDOFFILE { YYABORT; }
 
 string_opt: | STRING
 BOOLEAN: 't' | 'f'
@@ -464,19 +466,23 @@ hoayy::parser::error(const location_type& location,
 
 namespace spot
 {
-  hoa_aut_ptr
-  hoa_parse(const std::string& name,
-	      hoa_parse_error_list& error_list,
-	      const bdd_dict_ptr& dict,
-	      ltl::environment& env,
-	      bool debug)
+  hoa_stream_parser::hoa_stream_parser(const std::string& name)
   {
     if (hoayyopen(name))
-      {
-	error_list.emplace_back(spot::location(),
-				std::string("Cannot open file ") + name);
-	return 0;
-      }
+      throw std::runtime_error(std::string("Cannot open file ") + name);
+  }
+
+  hoa_stream_parser::~hoa_stream_parser()
+  {
+    hoayyclose();
+  }
+
+  hoa_aut_ptr
+  hoa_stream_parser::parse(hoa_parse_error_list& error_list,
+			   const bdd_dict_ptr& dict,
+			   ltl::environment& env,
+			   bool debug)
+  {
     result_ r;
     r.h = std::make_shared<spot::hoa_aut>();
     r.h->aut = make_tgba_digraph(dict);
@@ -485,10 +491,8 @@ namespace spot
     parser.set_debug_level(debug);
     if (parser.parse())
       r.h->aut = nullptr;
-    hoayyclose();
     if (!r.h->aut)
       return nullptr;
-
     if (r.start != -1)
       r.h->aut->set_init_state(r.start);
     else
@@ -498,7 +502,7 @@ namespace spot
 	r.h->aut->set_init_state(r.h->aut->new_state());
       }
     return r.h;
-  }
+  };
 }
 
 // Local Variables:

src/hoaparse/public.hh

@@ -51,7 +51,19 @@ namespace spot
   typedef std::shared_ptr<hoa_aut> hoa_aut_ptr;
   typedef std::shared_ptr<const hoa_aut> const_hoa_aut_ptr;
 
-  /// \brief Build a spot::tgba_digraph from ltl2hoa's output.
+  class SPOT_API hoa_stream_parser
+  {
+  public:
+    hoa_stream_parser(const std::string& filename);
+    ~hoa_stream_parser();
+    hoa_aut_ptr parse(hoa_parse_error_list& error_list,
+		      const bdd_dict_ptr& dict,
+		      ltl::environment& env =
+		      ltl::default_environment::instance(),
+		      bool debug = false);
+  };
+
+  /// \brief Build a spot::tgba_digraph from a HOA file.
   /// \param filename The name of the file to parse.
   /// \param error_list A list that will be filled with
   ///        parse errors that occured during parsing.
@@ -63,17 +75,29 @@ namespace spot
   ///        0 if the file could not be opened.
   ///
   /// Note that the parser usually tries to recover from errors.  It can
-  /// return an non zero value even if it encountered error during the
+  /// return a non zero value even if it encountered error during the
   /// parsing of \a filename.  If you want to make sure \a filename
   /// was parsed succesfully, check \a error_list for emptiness.
   ///
   /// \warning This function is not reentrant.
-  SPOT_API hoa_aut_ptr
+  inline hoa_aut_ptr
   hoa_parse(const std::string& filename,
 	    hoa_parse_error_list& error_list,
 	    const bdd_dict_ptr& dict,
 	    ltl::environment& env = ltl::default_environment::instance(),
-	    bool debug = false);
+	    bool debug = false)
+  {
+    try
+      {
+	hoa_stream_parser p(filename);
+	return p.parse(error_list, dict, env, debug);
+      }
+    catch (std::runtime_error& e)
+      {
+	error_list.emplace_back(spot::location(), e.what());
+	return nullptr;
+      }
+  }
 
   /// \brief Format diagnostics produced by spot::hoa_parse.
   /// \param os Where diagnostics should be output.