diff --git a/bin/autfilt.cc b/bin/autfilt.cc
index f509a0fd0..853a52de0 100644
--- a/bin/autfilt.cc
+++ b/bin/autfilt.cc
@@ -956,111 +956,21 @@ static int unused_ap(const spot::const_twa_graph_ptr& aut)
 
 namespace
 {
-  class hoa_processor final: public job_processor
+
+  struct autfilt_processor: hoa_processor
   {
   private:
     spot::postprocessor& post;
     automaton_printer printer;
   public:
-
-    hoa_processor(spot::postprocessor& post)
-      : post(post), printer(aut_input)
+    autfilt_processor(spot::postprocessor& post, spot::bdd_dict_ptr dict)
+      : hoa_processor(dict), post(post), printer(aut_input)
     {
     }
 
-    int
-    process_formula(spot::formula, const char*, int) override
-    {
-      SPOT_UNREACHABLE();
-    }
-
-    int process_string(const std::string& input, const char* filename,
-                       int linenum) override
-    {
-      std::ostringstream loc;
-      loc << filename << ':' << linenum;
-      std::string locstr = loc.str();
-      return process_automaton_stream
-        (spot::automaton_stream_parser(input.c_str(), locstr, opt_parse),
-         locstr.c_str());
-    }
-
-    int
-    aborted(const spot::const_parsed_aut_ptr& h, const char* filename)
-    {
-      std::cerr << filename << ':' << h->loc << ": aborted input automaton\n";
-      return 2;
-    }
-
-    int
-    process_file(const char* filename) override
-    {
-      // If we have a filename like "foo/NN" such
-      // that:
-      // ① foo/NN is not a file,
-      // ② NN is a number,
-      // ③ foo is a file,
-      // then it means we want to open foo as
-      // a CSV file and process column NN.
-      if (const char* slash = strrchr(filename, '/'))
-        {
-          char* end;
-          errno = 0;
-          long int col = strtol(slash + 1, &end, 10);
-          if (errno == 0 && !*end && col != 0)
-            {
-              struct stat buf;
-              if (stat(filename, &buf) != 0)
-                {
-                  col_to_read = col;
-                  if (real_filename)
-                    free(real_filename);
-                  real_filename = strndup(filename, slash - filename);
-
-                  // Special case for stdin.
-                  if (real_filename[0] == '-' && real_filename[1] == 0)
-                    return process_stream(std::cin, real_filename);
-
-                  std::ifstream input(real_filename);
-                  if (input)
-                    return process_stream(input, real_filename);
-
-                  error(2, errno, "cannot open '%s' nor '%s'",
-                        filename, real_filename);
-                }
-            }
-        }
-
-      return process_automaton_stream(spot::automaton_stream_parser(filename,
-                                                                    opt_parse),
-                                      filename);
-    }
-
-    int process_automaton_stream(spot::automaton_stream_parser&& hp,
-                                 const char* filename)
-    {
-      int err = 0;
-      while (!abort_run)
-        {
-          auto haut = hp.parse(opt->dict);
-          if (!haut->aut && haut->errors.empty())
-            break;
-          if (haut->format_errors(std::cerr))
-            err = 2;
-          if (!haut->aut)
-            error(2, 0, "failed to read automaton from %s", filename);
-          else if (haut->aborted)
-            err = std::max(err, aborted(haut, filename));
-          else
-            process_automaton(haut, filename);
-        }
-      return err;
-    }
-
-
     int
     process_automaton(const spot::const_parsed_aut_ptr& haut,
-                      const char* filename)
+                      const char* filename) override
     {
       process_timer timer;
       timer.start();
@@ -1379,7 +1289,7 @@ main(int argc, char** argv)
       post.set_type(type);
       post.set_level(level);
 
-      hoa_processor processor(post);
+      autfilt_processor processor(post, o.dict);
       if (processor.run())
         return 2;
 
diff --git a/bin/common_hoaread.hh b/bin/common_hoaread.hh
index 100e675e1..2a670cafb 100644
--- a/bin/common_hoaread.hh
+++ b/bin/common_hoaread.hh
@@ -1,5 +1,5 @@
 // -*- coding: utf-8 -*-
-// Copyright (C) 2015 Laboratoire de Recherche et Développement de
+// Copyright (C) 2015, 2017 Laboratoire de Recherche et Développement de
 // l'Epita (LRDE).
 //
 // This file is part of Spot, a model checking library.
@@ -20,9 +20,16 @@
 #pragma once
 
 #include "common_sys.hh"
+#include "error.h"
 
 #include <argp.h>
+#include <cstring>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <iostream>
+#include <fstream>
 
+#include "common_finput.hh"
 #include <spot/parseaut/public.hh>
 
 
@@ -32,3 +39,108 @@ extern spot::automaton_parser_options opt_parse;
 
 spot::twa_graph_ptr
 read_automaton(const char* filename, spot::bdd_dict_ptr& dict);
+
+
+class hoa_processor: public job_processor
+{
+  spot::bdd_dict_ptr dict_;
+public:
+
+  hoa_processor(spot::bdd_dict_ptr dict)
+    : dict_(dict)
+  {
+  }
+
+  int
+  process_formula(spot::formula, const char*, int) override
+  {
+    SPOT_UNREACHABLE();
+  }
+
+  virtual int
+  process_automaton(const spot::const_parsed_aut_ptr& haut,
+                    const char* filename) = 0;
+
+  int process_string(const std::string& input, const char* filename,
+                     int linenum) override
+  {
+    std::ostringstream loc;
+    loc << filename << ':' << linenum;
+    std::string locstr = loc.str();
+    return process_automaton_stream
+      (spot::automaton_stream_parser(input.c_str(), locstr, opt_parse),
+       locstr.c_str());
+  }
+
+  int
+  aborted(const spot::const_parsed_aut_ptr& h, const char* filename)
+  {
+    std::cerr << filename << ':' << h->loc << ": aborted input automaton\n";
+    return 2;
+  }
+
+  int
+  process_file(const char* filename) override
+  {
+    // If we have a filename like "foo/NN" such
+    // that:
+    // ① foo/NN is not a file,
+    // ② NN is a number,
+    // ③ foo is a file,
+    // then it means we want to open foo as
+    // a CSV file and process column NN.
+    if (const char* slash = strrchr(filename, '/'))
+      {
+        char* end;
+        errno = 0;
+        long int col = strtol(slash + 1, &end, 10);
+        if (errno == 0 && !*end && col != 0)
+          {
+            struct stat buf;
+            if (stat(filename, &buf) != 0)
+              {
+                col_to_read = col;
+                if (real_filename)
+                  free(real_filename);
+                real_filename = strndup(filename, slash - filename);
+
+                // Special case for stdin.
+                if (real_filename[0] == '-' && real_filename[1] == 0)
+                  return process_stream(std::cin, real_filename);
+
+                std::ifstream input(real_filename);
+                if (input)
+                  return process_stream(input, real_filename);
+
+                error(2, errno, "cannot open '%s' nor '%s'",
+                      filename, real_filename);
+              }
+          }
+      }
+
+    return process_automaton_stream(spot::automaton_stream_parser(filename,
+                                                                  opt_parse),
+                                    filename);
+  }
+
+  int process_automaton_stream(spot::automaton_stream_parser&& hp,
+                               const char* filename)
+  {
+    int err = 0;
+    while (!abort_run)
+      {
+        auto haut = hp.parse(dict_);
+        if (!haut->aut && haut->errors.empty())
+          break;
+        if (haut->format_errors(std::cerr))
+          err = 2;
+        if (!haut->aut)
+          error(2, 0, "failed to read automaton from %s", filename);
+        else if (haut->aborted)
+          err = std::max(err, aborted(haut, filename));
+        else
+          process_automaton(haut, filename);
+      }
+    return err;
+  }
+};
diff --git a/bin/dstar2tgba.cc b/bin/dstar2tgba.cc
index 505e6b303..3ecc408d4 100644
--- a/bin/dstar2tgba.cc
+++ b/bin/dstar2tgba.cc
@@ -1,5 +1,5 @@
 // -*- coding: utf-8 -*-
-// Copyright (C) 2013, 2014, 2015, 2016 Laboratoire de Recherche et
+// Copyright (C) 2013, 2014, 2015, 2016, 2017 Laboratoire de Recherche et
 // Développement de l'Epita (LRDE).
 //
 // This file is part of Spot, a model checking library.
@@ -108,110 +108,20 @@ parse_opt(int key, char* arg, struct argp_state*)
 
 namespace
 {
-  class dstar_processor final: public job_processor
+  class dstar_processor final: public hoa_processor
   {
   public:
     spot::postprocessor& post;
     automaton_printer printer;
 
     dstar_processor(spot::postprocessor& post)
-      : post(post), printer(aut_input)
+      : hoa_processor(spot::make_bdd_dict()), post(post), printer(aut_input)
     {
     }
 
-    int
-    process_formula(spot::formula, const char*, int) override
-    {
-      SPOT_UNREACHABLE();
-    }
-
-    int process_string(const std::string& input, const char* filename,
-                       int linenum) override
-    {
-      std::ostringstream loc;
-      loc << filename << ':' << linenum;
-      std::string locstr = loc.str();
-      return process_automaton_stream
-        (spot::automaton_stream_parser(input.c_str(), locstr, opt_parse),
-         locstr.c_str());
-    }
-
-    int
-    aborted(const spot::const_parsed_aut_ptr& h, const char* filename)
-    {
-      std::cerr << filename << ':' << h->loc << ": aborted input automaton\n";
-      return 2;
-    }
-
-    int
-    process_file(const char* filename) override
-    {
-      // If we have a filename like "foo/NN" such
-      // that:
-      // ① foo/NN is not a file,
-      // ② NN is a number,
-      // ③ foo is a file,
-      // then it means we want to open foo as
-      // a CSV file and process column NN.
-      if (const char* slash = strrchr(filename, '/'))
-        {
-          char* end;
-          errno = 0;
-          long int col = strtol(slash + 1, &end, 10);
-          if (errno == 0 && !*end && col != 0)
-            {
-              struct stat buf;
-              if (stat(filename, &buf) != 0)
-                {
-                  col_to_read = col;
-                  if (real_filename)
-                    free(real_filename);
-                  real_filename = strndup(filename, slash - filename);
-
-                  // Special case for stdin.
-                  if (real_filename[0] == '-' && real_filename[1] == 0)
-                    return process_stream(std::cin, real_filename);
-
-                  std::ifstream input(real_filename);
-                  if (input)
-                    return process_stream(input, real_filename);
-
-                  error(2, errno, "cannot open '%s' nor '%s'",
-                        filename, real_filename);
-                }
-            }
-        }
-
-      return process_automaton_stream(spot::automaton_stream_parser(filename,
-                                                                    opt_parse),
-                                      filename);
-    }
-
-    int process_automaton_stream(spot::automaton_stream_parser&& hp,
-                                 const char* filename)
-    {
-      int err = 0;
-      while (!abort_run)
-        {
-          auto haut = hp.parse(spot::make_bdd_dict());
-          if (!haut->aut && haut->errors.empty())
-            break;
-          if (haut->format_errors(std::cerr))
-            err = 2;
-          if (!haut->aut)
-            error(2, 0, "failed to read automaton from %s", filename);
-          else if (haut->aborted)
-            err = std::max(err, aborted(haut, filename));
-          else
-            process_automaton(haut, filename);
-        }
-      return err;
-    }
-
-
     int
     process_automaton(const spot::const_parsed_aut_ptr& haut,
-                      const char* filename)
+                      const char* filename) override
     {
       process_timer timer;
       timer.start();