spot::sbacc() works on alternating automata, fix dualize

Fixes #273.

* NEWS: Mention this.
* spot/twaalgos/dualize.cc, tests/python/dualize.py: Adapt dualize.
* spot/twaalgos/sbacc.cc, tests/core/sbacc.test: sbacc support
  alternating automata

NEWS

@@ -148,6 +148,8 @@ New in spot 2.3.5.dev (not yet released)
     input automaton with generalized Büchi/co-Büchi acceptance and
     convert it to a weak alternating automaton.
 
+  - spot::sbacc() is now able to work on alternating automata.
+
   Python:
 
   - The 'spot.gen' package exports the functions from libspotgen.

spot/twaalgos/dualize.cc

@@ -24,6 +24,9 @@
 #include <spot/twaalgos/complete.hh>
 #include <spot/twaalgos/dualize.hh>
 #include <spot/twaalgos/isdet.hh>
+#include <spot/twaalgos/sbacc.hh>
+
+#include <memory>
 
 namespace spot
 {
@@ -272,7 +275,9 @@ namespace spot
 
     public:
       dualizer(const const_twa_graph_ptr& aut)
-        : aut_(aut),
+        : aut_(is_universal(aut)
+                ? aut
+                : sbacc(std::const_pointer_cast<spot::twa_graph>(aut))),
           state_to_var_(aut_->num_states(), bddfalse),
           true_state_(-1U),
           acc_(0U),

spot/twaalgos/sbacc.cc

@@ -30,9 +30,6 @@ namespace spot
   {
     if (old->prop_state_acc())
       return old;
-    if (!old->is_existential())
-      throw std::runtime_error
-        ("sbacc() does not support alternation");
 
     // We will need a mark that is rejecting to mark rejecting states.
     // If no such mark exist, our work is actually quite simple: we
@@ -56,16 +53,18 @@ namespace spot
     // Marks that label one incoming transition from the same SCC.
     std::vector<acc_cond::mark_t> one_in(ns, 0U);
     for (auto& e: old->edges())
-      if (si.scc_of(e.src) == si.scc_of(e.dst))
-        {
-          common_in[e.dst] &= e.acc;
-          common_out[e.src] &= e.acc;
-        }
+      for (unsigned d: old->univ_dests(e.dst))
+        if (si.scc_of(e.src) == si.scc_of(d))
+          {
+            common_in[d] &= e.acc;
+            common_out[e.src] &= e.acc;
+          }
     for (unsigned s = 0; s < ns; ++s)
       common_out[s] |= common_in[s];
     for (auto& e: old->edges())
-      if (si.scc_of(e.src) == si.scc_of(e.dst))
-        one_in[e.dst] = e.acc - common_out[e.src];
+      for (unsigned d: old->univ_dests(e.dst))
+        if (si.scc_of(e.src) == si.scc_of(d))
+          one_in[d] = e.acc - common_out[e.src];
 
     auto res = make_twa_graph(old->get_dict());
     res->copy_ap_of(old);
@@ -92,14 +91,24 @@ namespace spot
         return p.first->second;
       };
 
-    unsigned old_init = old->get_init_state_number();
-    acc_cond::mark_t init_acc = 0U;
-    if (!si.is_rejecting_scc(si.scc_of(old_init)))
-      // Use any edge going into the initial state to set the first
-      // acceptance mark.
-      init_acc = one_in[old_init] | common_out[old_init];
+    std::vector<unsigned> old_init;
+    for (unsigned d: old->univ_dests(old->get_init_state_number()))
+      old_init.push_back(d);
+
+    std::vector<unsigned> old_st;
+    internal::univ_dest_mapper<twa_graph::graph_t> uniq(res->get_graph());
+    for (unsigned s: old_init)
+      {
+        acc_cond::mark_t init_acc = 0U;
+        if (!si.is_rejecting_scc(si.scc_of(s)))
+          // Use any edge going into the initial state to set the first
+          // acceptance mark.
+          init_acc = one_in[s] | common_out[s];
+
+        old_st.push_back(new_state(s, init_acc));
+      }
+    res->set_init_state(uniq.new_univ_dests(old_st.begin(), old_st.end()));
 
-    res->set_init_state(new_state(old_init, init_acc));
     while (!todo.empty())
       {
         auto one = todo.back();
@@ -108,20 +117,27 @@ namespace spot
         bool maybe_accepting = !si.is_rejecting_scc(scc_src);
         for (auto& t: old->out(one.first.first))
           {
-            unsigned scc_dst = si.scc_of(t.dst);
-            acc_cond::mark_t acc = 0U;
-            bool dst_acc = !si.is_rejecting_scc(scc_dst);
-            if (maybe_accepting && scc_src == scc_dst)
-              acc = t.acc - common_out[t.src];
-            else if (dst_acc)
-              // We enter a new accepting SCC. Use any edge going into
-              // t.dst from this SCC to set the initial acceptance mark.
-              acc = one_in[t.dst];
-            if (dst_acc)
-              acc |= common_out[t.dst];
-            else
-              acc = unsat_mark.second;
-            res->new_edge(one.second, new_state(t.dst, acc),
+            std::vector<unsigned> dests;
+            for (unsigned d: old->univ_dests(t.dst))
+              {
+                unsigned scc_dst = si.scc_of(d);
+                acc_cond::mark_t acc = 0U;
+                bool dst_acc = !si.is_rejecting_scc(scc_dst);
+                if (maybe_accepting && scc_src == scc_dst)
+                  acc = t.acc - common_out[t.src];
+                else if (dst_acc)
+                  // We enter a new accepting SCC. Use any edge going into
+                  // t.dst from this SCC to set the initial acceptance mark.
+                  acc = one_in[d];
+                if (dst_acc)
+                  acc |= common_out[d];
+                else
+                  acc = unsat_mark.second;
+
+                dests.push_back(new_state(d, acc));
+              }
+            res->new_edge(one.second,
+                          uniq.new_univ_dests(dests.begin(), dests.end()),
                           t.cond, one.first.second);
           }
       }

tests/core/sbacc.test

@@ -224,3 +224,46 @@ State: 1
 EOF
 autfilt --sbacc taut.hoa > out.hoa
 diff out.hoa expect.hoa
+
+cat >alt.hoa <<EOF
+HOA: v1
+States: 4
+Start: 0
+AP: 1 "a"
+Acceptance: 2 Inf(0) & Inf(1)
+--BODY--
+State: 0
+[0] 1&2 {0}
+[0] 3 {0}
+State: 1
+[0] 0 {1}
+State: 2
+[t] 2
+State: 3
+[!0] 0
+--END--
+EOF
+
+cat >expect.hoa <<EOF
+HOA: v1
+States: 4
+Start: 0
+AP: 1 "a"
+acc-name: generalized-Buchi 2
+Acceptance: 2 Inf(0)&Inf(1)
+properties: univ-branch trans-labels explicit-labels state-acc
+--BODY--
+State: 0 {0}
+[0] 3
+[0] 1&2
+State: 1 {0 1}
+[0] 0
+State: 2
+[t] 2
+State: 3 {0}
+[!0] 0
+--END--
+EOF
+
+autfilt --sbacc alt.hoa > out.hoa
+diff out.hoa expect.hoa

tests/python/dualize.py

@@ -394,12 +394,11 @@ State: 2
 [0] 2
 --END--""")
 
-
 dual = spot.dualize(aut)
 h = dual.to_str('hoa')
 
 assert h == """HOA: v1
-States: 2
+States: 3
 Start: 0
 AP: 2 "a" "b"
 acc-name: all
@@ -407,9 +406,11 @@ Acceptance: 0 t
 properties: trans-labels explicit-labels state-acc deterministic
 --BODY--
 State: 0
-[!0 | !1] 1
+[0&1] 1
+[!0 | !1] 2
 State: 1
-[t] 1
+State: 2
+[t] 2
 --END--"""
 
 aut = spot.automaton("""
@@ -492,6 +493,45 @@ State: 2 {0}
 [t] 2
 --END--"""
 
+aut = spot.automaton("""
+HOA: v1
+States: 3
+Start: 0
+AP: 1 "a"
+Acceptance: 2 Fin(0) & Inf(1)
+properties: trans-labels explicit-labels
+--BODY--
+State: 0
+[!0] 0
+[0] 1 {0}
+[0] 2 {1}
+State: 1
+[t] 0
+State: 2
+[t] 0
+--END--""")
+
+dual = spot.dualize(aut)
+assert dualtype(aut, dual)
+h = dual.to_str('hoa')
+
+assert h == """HOA: v1
+States: 3
+Start: 0
+AP: 1 "a"
+acc-name: parity min even 2
+Acceptance: 2 Inf(0) | Fin(1)
+properties: univ-branch trans-labels explicit-labels state-acc complete
+properties: deterministic
+--BODY--
+State: 0
+[!0] 0
+[0] 1&2
+State: 1 {0}
+[t] 0
+State: 2 {1}
+[t] 0
+--END--"""
 
 aut = spot.translate('G!a R XFb')
 test_assert(aut)
@@ -499,12 +539,12 @@ dual = spot.dualize(aut)
 h = dual.to_str('hoa')
 
 assert h == """HOA: v1
-States: 5
+States: 6
 Start: 0
 AP: 2 "a" "b"
 acc-name: co-Buchi
 Acceptance: 1 Fin(0)
-properties: univ-branch trans-labels explicit-labels trans-acc complete
+properties: univ-branch trans-labels explicit-labels state-acc complete
 properties: deterministic
 --BODY--
 State: 0
@@ -512,17 +552,22 @@ State: 0
 [!0] 1&2
 State: 1
 [0&!1] 1
-[0&1] 1 {0}
+[0&1] 4
+[!0&1] 2&4
 [!0&!1] 1&2
-[!0&1] 1&2 {0}
 State: 2
 [!0&1] 3
-[0 | !1] 4
-State: 3
-[!0] 3 {0}
-[0] 4
-State: 4
-[t] 4
+[0 | !1] 5
+State: 3 {0}
+[!0] 3
+[0] 5
+State: 4 {0}
+[0&!1] 1
+[0&1] 4
+[!0&1] 2&4
+[!0&!1] 1&2
+State: 5
+[t] 5
 --END--"""