postproc: add fine-tuning options for determinization

* spot/twaalgos/postproc.cc, spot/twaalgos/postproc.hh:
Add options det-scc, det-simul, det-stutter.
* bin/spot-x.cc: Document them.
* doc/org/ltl2tgba.org: Illustrate one of them and link
to the spot-x man page.

bin/spot-x.cc

@@ -1,5 +1,5 @@
 // -*- coding: utf-8 -*-
-// Copyright (C) 2013, 2014, 2015 Laboratoire de Recherche et
+// Copyright (C) 2013, 2014, 2015, 2016 Laboratoire de Recherche et
 // Développement de l'Epita (LRDE).
 //
 // This file is part of Spot, a model checking library.
@@ -91,6 +91,12 @@ has an accepting self-loop, then level L is replaced by the accepting \
 level, as it might favor finding accepting cycles earlier.  If \
 degen-lowinit is non-zero, then level L is always used without looking \
 for the presence of an accepting self-loop.") },
+    { DOC("det-scc", "Set to 0 to disable scc-based optimizations in \
+the determinization algorithm.") },
+    { DOC("det-simul", "Set to 0 to disable simulation-based optimizations in \
+the determinization algorithm.") },
+    { DOC("det-stutter", "Set to 0 to disable optimizations based on \
+the stutter-invariance in the determinization algorithm.") },
     { DOC("simul", "Set to 0 to disable simulation-based reductions. \
 Set to 1 to use only direct simulation. Set to 2 to use only reverse \
 simulation. Set to 3 to iterate both direct and reverse simulations. \

doc/org/ltl2tgba.org

@@ -729,7 +729,7 @@ expectations.
    deterministic TGBA exists.
 
 #+NAME: ltl2tgba-fga
-#+BEGIN_SRC sh :results verbatim :exports none
+#+BEGIN_SRC sh :results verbatim :exports code
 ltl2tgba "FGa" -D -d.a
 #+END_SRC
 
@@ -743,7 +743,7 @@ ltl2tgba "FGa" -D -d.a
    But with =--generic=, =ltl2tgba= will output the following Rabin automaton:
 
 #+NAME: ltl2tgba-fga-D
-#+BEGIN_SRC sh :results verbatim :exports none
+#+BEGIN_SRC sh :results verbatim :exports code
 ltl2tgba "FGa" -G -D -d.a
 #+END_SRC
 
@@ -758,6 +758,40 @@ Note that determinization algorithm implemented actually outputs
 parity acceptance, but =Fin(0)&Inf(1)= can be interpreted either as
 =Rabin 1= or =parity min odd 2=.
 
+
+The [[./man/spot-x.7.html][=spot-x=]](7) man page lists a few =-x= options (=det-scc=,
+=det-simul=, =det-stutter=) of the determinization algorithm that are
+enable by default, but that you may want to disable for experimental
+purpose.
+
+For instance the following deterministic automaton
+
+#+NAME: ltl2tgba-det1
+#+BEGIN_SRC sh :results verbatim :exports code
+ltl2tgba "F(a W FGb)" -G -D -d.a
+#+END_SRC
+
+#+BEGIN_SRC dot :file ltl2tgba-det1.png :cmdline -Tpng :var txt=ltl2tgba-det1 :exports results
+  $txt
+#+END_SRC
+
+#+RESULTS:
+[[file:ltl2tgba-det1.png]]
+
+would be larger if SCC-based optimizations were disabled:
+
+#+NAME: ltl2tgba-det2
+#+BEGIN_SRC sh :results verbatim :exports code
+ltl2tgba "F(a W FGb)" -x '!det-scc' -G -D -d.a
+#+END_SRC
+
+#+BEGIN_SRC dot :file ltl2tgba-det2.png :cmdline -Tpng :var txt=ltl2tgba-det2 :exports results
+  $txt
+#+END_SRC
+
+#+RESULTS:
+[[file:ltl2tgba-det2.png]]
+
 * Translating multiple formulas for statistics
 
 If multiple formulas are given to =ltl2tgba=, the corresponding

spot/twaalgos/postproc.cc

@@ -53,12 +53,6 @@ namespace spot
   }
 
   postprocessor::postprocessor(const option_map* opt)
-    : type_(TGBA), pref_(Small), level_(High),
-      degen_reset_(true), degen_order_(false), degen_cache_(true),
-      degen_lskip_(true), degen_lowinit_(false), simul_(-1),
-      scc_filter_(-1), ba_simul_(-1),
-      tba_determinisation_(false), sat_minimize_(0), sat_acc_(0),
-      sat_states_(0), state_based_(false), wdba_minimize_(true)
   {
     if (opt)
       {
@@ -67,6 +61,9 @@ namespace spot
 	degen_cache_ = opt->get("degen-lcache", 1);
 	degen_lskip_ = opt->get("degen-lskip", 1);
 	degen_lowinit_ = opt->get("degen-lowinit", 0);
+	det_scc_ = opt->get("det-scc", 1);
+	det_simul_ = opt->get("det-simul", 1);
+	det_stutter_ = opt->get("det-stutter", 1);
 	simul_ = opt->get("simul", -1);
 	scc_filter_ = opt->get("scc-filter", -1);
 	ba_simul_ = opt->get("ba-simul", -1);
@@ -366,7 +363,8 @@ namespace spot
 
     if (PREF_ == Deterministic && type_ == Generic && !dba)
       {
-	dba = tgba_determinize(to_generalized_buchi(sim));
+	dba = tgba_determinize(to_generalized_buchi(sim),
+			       false, det_scc_, det_simul_, det_stutter_);
 	if (level_ != Low)
 	  dba = simulation(dba);
 	sim = nullptr;

spot/twaalgos/postproc.hh

@@ -172,24 +172,27 @@ namespace spot
     twa_graph_ptr do_scc_filter(const twa_graph_ptr& a, bool arg);
     twa_graph_ptr do_scc_filter(const twa_graph_ptr& a);
 
-    output_type type_;
+    output_type type_ = TGBA;
-    int pref_;
+    int pref_ = Small;
-    optimization_level level_;
+    optimization_level level_ = High;
     // Fine-tuning options fetched from the option_map.
-    bool degen_reset_;
+    bool degen_reset_ = true;
-    bool degen_order_;
+    bool degen_order_ = false;
-    int degen_cache_;
+    int degen_cache_ = true;
-    bool degen_lskip_;
+    bool degen_lskip_ = true;
-    bool degen_lowinit_;
+    bool degen_lowinit_ = false;
-    int simul_;
+    bool det_scc_ = true;
-    int scc_filter_;
+    bool det_simul_ = true;
-    int ba_simul_;
+    bool det_stutter_ = true;
-    bool tba_determinisation_;
+    int simul_ = -1;
-    int sat_minimize_;
+    int scc_filter_ = -1;
-    int sat_acc_;
+    int ba_simul_ = -1;
-    int sat_states_;
+    bool tba_determinisation_ = false;
-    bool state_based_;
+    int sat_minimize_ = 0;
-    bool wdba_minimize_;
+    int sat_acc_ = 0;
+    int sat_states_ = 0;
+    bool state_based_ = false;
+    bool wdba_minimize_ = true;
   };
   /// @}
 }