dot: add a <N option

* spot/twaalgos/dot.cc: Implement it.
* spot/taalgos/dot.cc: Ignore it.
* spot/twaalgos/copy.cc, spot/twaalgos/copy.hh: Add option
to limit the number of states.
* tests/python/ltsmin.ipynb: Improve test case.
* tests/Makefile.am: Cleanup the files generated by ltsmin.ipynb.
* python/spot/__init__.py (setup): Add a max_states argument
that default to 50.
* bin/common_aoutput.cc: Mention the <INT option.
* NEWS: Likewise.

NEWS

@@ -12,11 +12,23 @@ New in spot 1.99.7a (not yet released)
     object can be queried about the supported variables and their
     types.
 
+  * print_dot() now accepts an option of the form "<N" to specify
+    a maximum number of states to output.  Incomplete states are
+    then marked appropriately.  For a quick example, compare
+       ltl2tgba -D 'Ga | Gb | Gc' -d'<3'
+    with
+       ltl2tgba -D 'Ga | Gb | Gc' -d
+
   Python:
 
   * The ltsmin interface has been binded in Python.  See
     https://spot.lrde.epita.fr/ipynb/ltsmin.html for a short example.
 
+  * spot.setup() sets de maximum number of states to display in
+    automata to 50 by default, as more states is likely to be
+    unreadable (and slow to process by GraphViz).  This can be
+    overridden by calling spot.setup(max_states=N).
+
   Documentation:
 
   * There is a new page giving informal illustrations (and extra

bin/common_aoutput.cc

@@ -80,7 +80,7 @@ static const argp_option options[] =
   {
     /**************************************************/
     { nullptr, 0, nullptr, 0, "Output format:", 3 },
-    { "dot", 'd', "1|a|b|B|c|e|f(FONT)|h|n|N|o|r|R|s|t|v|+INT",
+    { "dot", 'd', "1|a|b|B|c|e|f(FONT)|h|n|N|o|r|R|s|t|v|+INT|<INT",
       OPTION_ARG_OPTIONAL,
       "GraphViz's format.  Add letters for "
       "(1) force numbered states, "
@@ -93,7 +93,8 @@ static const argp_option options[] =
       "(r) rainbow colors for acceptance sets, "
       "(R) color acceptance sets by Inf/Fin, (s) with SCCs, "
       "(t) force transition-based acceptance, "
-      "(+INT) add INT to all set numbers", 0 },
+      "(+INT) add INT to all set numbers, "
+      "(<INT) display at most INT states", 0 },
     { "hoaf", 'H', "i|l|m|s|t|v", OPTION_ARG_OPTIONAL,
       "Output the automaton in HOA format (default).  Add letters to select "
       "(i) use implicit labels for complete deterministic automata, "

python/spot/__init__.py

@@ -71,6 +71,8 @@ def setup(**kwargs):
         the font to use in the GraphViz output (default: 'Lato')
     show_default : str
         default options for show()
+    max_states : int
+        maximum number of states in GraphViz output (default: 50)
     """
     import os
 
@@ -80,7 +82,8 @@ def setup(**kwargs):
                                            kwargs.get('fillcolor', '#ffffaa'))
 
     bullets = 'B' if kwargs.get('bullets', True) else ''
-    d = 'rf({})'.format(kwargs.get('font', 'Lato')) + bullets
+    max_states = '<' + str(kwargs.get('max_states', 50))
+    d = 'rf({})'.format(kwargs.get('font', 'Lato')) + bullets + max_states
     global _show_default
     _show_default = kwargs.get('show_default', None)
     os.environ['SPOT_DOTDEFAULT'] = d

spot/taalgos/dot.cc

@@ -1,6 +1,6 @@
 // -*- coding: utf-8 -*-
-// Copyright (C) 2010, 2012, 2014, 2015 Laboratoire de Recherche et
+// Copyright (C) 2010, 2012, 2014, 2015, 2016 Laboratoire de Recherche
-// Developpement de l Epita (LRDE).
+// et Developpement de l Epita (LRDE).
 //
 // This file is part of Spot, a model checking library.
 //
@@ -84,7 +84,16 @@ namespace spot
 	    case 'v':
 	      opt_horizontal_ = false;
 	      break;
+	    case '0':
 	    case '1':
+	    case '2':
+	    case '3':
+	    case '4':
+	    case '5':
+	    case '6':
+	    case '7':
+	    case '8':
+	    case '9':
 	    case 'a':
 	    case 'b':
 	    case 'B':
@@ -96,6 +105,8 @@ namespace spot
 	    case 'R':
 	    case 's':
 	    case 't':
+	    case '+':
+	    case '<':
 	      // All these options are implemented by dotty() on TGBA,
 	      // but are not implemented here.  We simply ignore them,
 	      // because raising an exception if they are in

spot/twaalgos/copy.cc

@@ -27,13 +27,15 @@
 namespace spot
 {
   twa_graph_ptr
-  copy(const const_twa_ptr& aut, twa::prop_set p, bool preserve_names)
+  copy(const const_twa_ptr& aut, twa::prop_set p,
+       bool preserve_names, unsigned max_states)
   {
     twa_graph_ptr out = make_twa_graph(aut->get_dict());
     out->copy_acceptance_of(aut);
     out->copy_ap_of(aut);
     out->prop_copy(aut, p);
     std::vector<std::string>* names = nullptr;
+    std::set<unsigned>* incomplete = nullptr;
     if (preserve_names)
       {
 	names = new std::vector<std::string>;
@@ -69,9 +71,27 @@ namespace spot
 	unsigned src2;
 	std::tie(src1, src2) = *todo.front();
 	todo.pop_front();
-
 	for (auto* t: aut->succ(src1))
-	  out->new_edge(src2, new_state(t->dst()), t->cond(), t->acc());
+	  {
+	    if (SPOT_UNLIKELY(max_states < out->num_states()))
+	      {
+		// If we have reached the max number of state, never try
+		// to create a new one.
+		auto i = seen.find(t->dst());
+		if (i == seen.end())
+		  {
+		    if (!incomplete)
+		      incomplete = new std::set<unsigned>;
+		    incomplete->insert(src2);
+		    continue;
+		  }
+		out->new_edge(src2, i->second, t->cond(), t->acc());
+	      }
+	    else
+	      {
+		out->new_edge(src2, new_state(t->dst()), t->cond(), t->acc());
+	      }
+	  }
       }
 
 
@@ -84,6 +104,8 @@ namespace spot
 	ptr->destroy();
       }
 
+    if (incomplete)
+      out->set_named_prop("incomplete-states", incomplete);
     return out;
   }
 }

spot/twaalgos/copy.hh

@@ -33,5 +33,6 @@ namespace spot
   ///
   /// This works for using the abstract interface for automata
   SPOT_API twa_graph_ptr
-  copy(const const_twa_ptr& aut, twa::prop_set p, bool preserve_names = false);
+  copy(const const_twa_ptr& aut, twa::prop_set p,
+       bool preserve_names = false, unsigned max_states = -1U);
 }

spot/twaalgos/dot.cc

@@ -57,6 +57,7 @@ namespace spot
       const_twa_graph_ptr aut_;
       std::vector<std::string>* sn_ = nullptr;
       std::vector<std::pair<unsigned, unsigned>>* sprod_ = nullptr;
+      std::set<unsigned>* incomplete_;
       std::string* name_ = nullptr;
       acc_cond::mark_t inf_sets_ = 0U;
       acc_cond::mark_t fin_sets_ = 0U;
@@ -83,9 +84,21 @@ namespace spot
 	};
       const char*const* palette = palette9;
       int palette_mod = 9;
+      unsigned max_states_ = -1U;
+      bool max_states_given_ = false;
 
     public:
 
+      unsigned max_states()
+      {
+	return max_states_;
+      }
+
+      bool max_states_given()
+      {
+	return max_states_given_;
+      }
+
       void
       parse_opts(const char* options)
       {
@@ -95,7 +108,7 @@ namespace spot
 	    {
 	    case '.':
 	      {
-	        // Copy the value in a string, so future calls to
+		// Copy the value in a string, so future calls to
 		// parse_opts do not fail if the environment has
 		// changed.  (This matters particularly in an ipython
 		// notebook, where it is tempting to redefine
@@ -123,6 +136,25 @@ namespace spot
 		options = end;
 		break;
 	      }
+	    case '<':
+	      {
+		char* end;
+		max_states_ = strtoul(options, &end, 10);
+		if (options == end)
+		  throw std::runtime_error
+		    ("missing number after '<' in print_dot() options");
+		if (max_states_ == 0)
+		  {
+		    max_states_ = -1U;
+		    max_states_given_ = false;
+		  }
+		else
+		  {
+		    max_states_given_ = true;
+		  }
+		options = end;
+		break;
+	      }
 	    case '1':
 	      opt_want_state_names_ = false;
 	      break;
@@ -445,6 +477,9 @@ namespace spot
 	      os_ << ", peripheries=2";
 	    os_ << "]\n";
 	  }
+	if (incomplete_ && incomplete_->find(s) != incomplete_->end())
+	  os_ << "  u" << s << " [label=\"...\", shape=none, width=0, height=0"
+	    "]\n  " << s << " -> u" << s << " [style=dashed]\n";
       }
 
       void
@@ -497,6 +532,8 @@ namespace spot
 		  sprod_ = nullptr;
 	      }
 	  }
+	incomplete_ =
+	  aut->get_named_prop<std::set<unsigned>>("incomplete-states");
 	if (opt_name_)
 	  name_ = aut_->get_named_prop<std::string>("automaton-name");
 	mark_states_ = (!opt_force_acc_trans_
@@ -566,8 +603,8 @@ namespace spot
   {
     dotty_output d(os, options);
     auto aut = std::dynamic_pointer_cast<const twa_graph>(g);
-    if (!aut)
+    if (!aut || (d.max_states_given() && aut->num_states() >= d.max_states()))
-      aut = copy(g, twa::prop_set::all(), true);
+      aut = copy(g, twa::prop_set::all(), true, d.max_states() - 1);
     d.print(aut);
     return os;
   }

tests/Makefile.am

@@ -316,7 +316,7 @@ TESTS_python = \
   python/trival.py
 endif
 
-CLEANFILES = python/finite.dve2C python/finite.dve.cpp
+CLEANFILES = python/test1.dve python/test1.dve2C python/test1.dve.cpp
 
 SUFFIXES = .ipynb .html
 .ipynb.html: