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parity: add spot::cleanup_parity_acceptance()

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Merge the acceptance sets of a parity acceptance with the same priority
level to simplify this acceptance.

* spot/twaalgos/parity.cc, spot/twaalgos/parity.hh: Here
* tests/core/parity.cc: Add tests for spot::cleanup_parity_acceptance()
This commit is contained in:
Laurent XU 2017-02-15 00:16:35 +01:00
parent 0bf0a99d6d
commit 3e650f18d9
3 changed files with 123 additions and 1 deletions
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88
spot/twaalgos/parity.cc
View file

@ -24,7 +24,6 @@
#include <utility>
#include <functional>
#include <queue>
#include <spot/twaalgos/hoa.hh>
namespace spot
{
@ -147,6 +146,93 @@ namespace spot
return aut;
}
twa_graph_ptr
cleanup_parity(const const_twa_graph_ptr& aut, bool keep_style)
{
auto result = make_twa_graph(aut, twa::prop_set::all());
return cleanup_parity_here(result, keep_style);
}
twa_graph_ptr
cleanup_parity_here(twa_graph_ptr aut, bool keep_style)
{
bool current_max;
bool current_odd;
if (!aut->acc().is_parity(current_max, current_odd, true))
throw new std::invalid_argument("cleanup_parity: input "
"must have a parity acceptance.");
auto num_sets = aut->num_sets();
if (num_sets == 0)
return aut;
// Compute all the used sets
auto used_in_aut = acc_cond::mark_t();
for (auto& t: aut->edges())
{
if (current_max)
{
auto maxset = t.acc.max_set();
if (maxset)
t.acc = acc_cond::mark_t{maxset - 1};
}
else
{
t.acc = t.acc.lowest();
}
used_in_aut |= t.acc;
}
if (used_in_aut)
{
// Never remove the least significant acceptance set, and mark the
// acceptance set 0 to keep the style if needed.
if (current_max || keep_style)
used_in_aut.set(0);
if (!current_max)
used_in_aut.set(num_sets - 1);
// Fill the vector shift with the new acceptance sets
std::vector<unsigned> shift(num_sets);
int prev_used = -1;
bool change_style = false;
unsigned new_index = 0;
for (auto i = 0U; i < num_sets; ++i)
if (used_in_aut.has(i))
{
if (prev_used == -1)
change_style = i % 2 != 0;
else if ((i + prev_used) % 2 != 0)
++new_index;
shift[i] = new_index;
prev_used = i;
}
// Update all the transitions with the vector shift
for (auto& t: aut->edges())
{
auto maxset = t.acc.max_set();
if (maxset)
t.acc = acc_cond::mark_t{shift[maxset - 1]};
}
auto new_num_sets = new_index + 1;
if (new_num_sets < num_sets)
{
auto new_acc = acc_cond::acc_code::parity(current_max,
current_odd != change_style,
new_num_sets);
aut->set_acceptance(new_num_sets, new_acc);
}
}
else
{
if ((current_max && current_odd)
|| (!current_max && current_odd != (num_sets % 2 == 0)))
aut->set_acceptance(0, acc_cond::acc_code::t());
else
aut->set_acceptance(0, acc_cond::acc_code::f());
}
return aut;
}
twa_graph_ptr
colorize_parity(const const_twa_graph_ptr& aut, bool keep_style)
{