acc: introduce fin_one_extract()

* spot/twa/acc.cc, spot/twa/acc.hh (acc_cond::fin_one_extract,
acc_code::acc_cond::fin_one_extract): New methods.
* python/spot/impl.i: Add support for the return type.
* tests/python/acc_cond.ipynb: Test them.
This commit is contained in:
Alexandre Duret-Lutz 2021-09-10 18:17:17 +02:00
parent 2d1cb0ddcd
commit 7fedb3dc61
4 changed files with 246 additions and 16 deletions

View file

@ -468,6 +468,8 @@ namespace std {
%template(liststr) list<std::string>;
%template(pairunsigned) pair<unsigned, unsigned>;
%template(pairmark_t) pair<spot::acc_cond::mark_t, spot::acc_cond::mark_t>;
%template(pairintacccode) pair<int, spot::acc_cond::acc_code>;
%template(pairintacccond) pair<int, spot::acc_cond>;
%template(vectorformula) vector<spot::formula>;
%template(vectorunsigned) vector<unsigned>;
%template(vectorpairunsigned) vector<pair<unsigned, unsigned>>;

View file

@ -2644,6 +2644,118 @@ namespace spot
return -1;
}
namespace
{
int has_top_fin(const acc_cond::acc_word* pos, bool top = true)
{
if (pos->sub.op == acc_cond::acc_op::Fin)
{
acc_cond::mark_t m = pos[-1].mark;
if (top || m.is_singleton())
return m.min_set() - 1;
}
else if (pos->sub.op == acc_cond::acc_op::And)
{
auto sub = pos - pos->sub.size;
do
{
--pos;
if (int f = has_top_fin(pos, false); f >= 0)
return f;
pos -= pos->sub.size;
}
while (sub < pos);
}
else if (top && pos->sub.op == acc_cond::acc_op::Or)
{
auto sub = pos - pos->sub.size;
do
{
--pos;
if (int f = has_top_fin(pos); f >= 0)
return f;
pos -= pos->sub.size;
}
while (sub < pos);
}
return -1;
}
bool uses_fin(const acc_cond::acc_word* pos, acc_cond::mark_t f)
{
auto sub = pos - pos->sub.size;
do
{
switch (pos->sub.op)
{
case acc_cond::acc_op::And:
case acc_cond::acc_op::Or:
--pos;
break;
case acc_cond::acc_op::Fin:
if (pos[-1].mark & f)
return true;
SPOT_FALLTHROUGH;
case acc_cond::acc_op::Inf:
case acc_cond::acc_op::InfNeg:
case acc_cond::acc_op::FinNeg:
pos -= 2;
break;
}
}
while (sub < pos);
return false;
}
acc_cond::acc_code extract_fin(const acc_cond::acc_word* pos,
acc_cond::mark_t f)
{
auto start = pos - pos->sub.size;
switch (pos->sub.op)
{
case acc_cond::acc_op::And:
case acc_cond::acc_op::Fin:
case acc_cond::acc_op::Inf:
return pos;
case acc_cond::acc_op::Or:
{
--pos;
auto res = acc_cond::acc_code::f();
do
{
if (uses_fin(pos, f))
{
acc_cond::acc_code tmp(pos);
tmp |= std::move(res);
std::swap(tmp, res);
}
pos -= pos->sub.size + 1;
}
while (pos > start);
return res;
}
case acc_cond::acc_op::FinNeg:
case acc_cond::acc_op::InfNeg:
SPOT_UNREACHABLE();
return {};
}
SPOT_UNREACHABLE();
return {};
}
}
std::pair<int, acc_cond::acc_code>
acc_cond::acc_code::fin_one_extract() const
{
if (is_t() || is_f())
return {-1, *this};
const acc_cond::acc_word* pos = &back();
int selected_fin = has_top_fin(pos);
if (selected_fin < 0)
selected_fin = fin_one();
return {selected_fin, extract_fin(pos, {(unsigned) selected_fin})};
}
namespace
{
bool

View file

@ -1251,12 +1251,6 @@ namespace spot
/// `Fin(0)&Fin(1)&(Inf(2)|Fin(3))`, this will return `{0,1}`.
mark_t fin_unit() const;
/// \brief Return one acceptance set i that appear as `Fin(i)`
/// in the condition.
///
/// Return -1 if no such set exist.
int fin_one() const;
/// \brief Find a `Inf(i)` that is a unit clause.
///
/// This return a mark_t `{i}` such that `Inf(i)` appears as a
@ -1270,6 +1264,31 @@ namespace spot
/// `Inf(0)&Inf(1)&(Inf(2)|Fin(3))`, this will return `{0,1}`.
mark_t inf_unit() const;
/// \brief Return one acceptance set i that appears as `Fin(i)`
/// in the condition.
///
/// Return -1 if no such set exist.
int fin_one() const;
/// \brief Return one acceptance set i that appears as `Fin(i)`
/// in the condition, and all disjuncts containing it.
///
/// If the condition is a disjunction and one of the disjunct
/// has the shape `...&Fin(i)&...`, then `i` will be prefered
/// over any arbitrary Fin.
///
/// The second element of the pair, is the same acceptance
/// condition in which all top-level disjunct not featuring
/// `Fin(i)` have been removed.
///
/// For example on
/// `Fin(1)&Inf(2)|Inf(3)&Inf(4)|Inf(5)&(Fin(1)|Fin(7))`
/// the output would be the pair
/// `(1, Fin(1)&Inf(2)|Inf(5)&(Fin(1)|Fin(7)))`.
/// On that example `Fin(1)` is prefered to `Fin(7)` because
/// it appears at the top-level.
std::pair<int, acc_code> fin_one_extract() const;
/// \brief Help closing accepting or rejecting cycle.
///
/// Assuming you have a partial cycle visiting all acceptance
@ -2157,15 +2176,6 @@ namespace spot
return code_.fin_unit();
}
/// \brief Return one acceptance set i that appear as `Fin(i)`
/// in the condition.
///
/// Return -1 if no such set exist.
int fin_one() const
{
return code_.fin_one();
}
/// \brief Find a `Inf(i)` that is a unit clause.
///
/// This return a mark_t `{i}` such that `Inf(i)` appears as a
@ -2182,6 +2192,38 @@ namespace spot
return code_.inf_unit();
}
/// \brief Return one acceptance set i that appear as `Fin(i)`
/// in the condition.
///
/// Return -1 if no such set exist.
int fin_one() const
{
return code_.fin_one();
}
/// \brief Return one acceptance set i that appears as `Fin(i)`
/// in the condition, and all disjuncts containing it.
///
/// If the condition is a disjunction and one of the disjunct
/// has the shape `...&Fin(i)&...`, then `i` will be prefered
/// over any arbitrary Fin.
///
/// The second element of the pair, is the same acceptance
/// condition in which all top-level disjunct not featuring
/// `Fin(i)` have been removed.
///
/// For example on
/// `Fin(1)&Inf(2)|Inf(3)&Inf(4)|Inf(5)&(Fin(1)|Fin(7))`
/// the output would be the pair
/// `(1, Fin(1)&Inf(2)|Inf(5)&(Fin(1)|Fin(7)))`.
/// On that example `Fin(1)` is prefered to `Fin(7)` because
/// it appears at the top-level.
std::pair<int, acc_cond> fin_one_extract() const
{
auto [f, c] = code_.fin_one_extract();
return {f, {num_sets(), std::move(c)}};
}
/// \brief Return the top-level disjuncts.
///
/// For instance, if the formula is

View file

@ -1409,6 +1409,80 @@
"print(acc.top_disjuncts())\n",
"print(acc.top_conjuncts())"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"`fin_one()` return the number of one color `x` that appears as `Fin(x)` in the formula, or `-1` if the formula is Fin-less.\n",
"\n",
"The variant `fin_one_extract()` consider the acceptance condition as a disjunction (if the top-level operator is not a disjunction, we just assume the formula is a disjunction with only one disjunct), and return a pair `(x,c)` where `c` is the disjunction of all disjuncts of the original formula where `Fin(x)` appear. Also this function tries to choose an `x` such that one of the disjunct has the form `...&Fin(x)&...` if possible: this is visible in the third example, where 5 is prefered to 2."
]
},
{
"cell_type": "code",
"execution_count": 55,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"(4, (Fin(0) | Inf(1)) & (Fin(2) | Inf(3)))\n",
"0\n",
"(0, spot.acc_cond(4, \"(Fin(0) | Inf(1)) & (Fin(2) | Inf(3))\"))\n"
]
}
],
"source": [
"print(acc)\n",
"print(acc.fin_one())\n",
"print(acc.fin_one_extract())"
]
},
{
"cell_type": "code",
"execution_count": 56,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"(6, (Fin(0) & Inf(1)) | (Fin(2) & Inf(3)) | (Fin(4) & Inf(5)))\n",
"0\n",
"(0, spot.acc_cond(6, \"Fin(0) & Inf(1)\"))\n"
]
}
],
"source": [
"acc2 = spot.acc_cond('Rabin 3')\n",
"print(acc2)\n",
"print(acc2.fin_one())\n",
"print(acc2.fin_one_extract())"
]
},
{
"cell_type": "code",
"execution_count": 57,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"(6, (Inf(0) & (Fin(2) | Inf(3))) | (Inf(4) & Fin(5)) | ((Inf(0)&Inf(5)) & (Fin(0)|Fin(5))))\n",
"2\n",
"(5, spot.acc_cond(6, \"(Inf(4) & Fin(5)) | ((Inf(0)&Inf(5)) & (Fin(0)|Fin(5)))\"))\n"
]
}
],
"source": [
"acc3 = spot.acc_cond('Inf(0)&(Fin(2)|Inf(3)) | Inf(4)&Fin(5) | Inf(0)&Inf(5)&(Fin(5)|Fin(0))')\n",
"print(acc3)\n",
"print(acc3.fin_one())\n",
"print(acc3.fin_one_extract())"
]
}
],
"metadata": {
@ -1427,7 +1501,7 @@
"name": "python",
"nbconvert_exporter": "python",
"pygments_lexer": "ipython3",
"version": "3.7.3rc1"
"version": "3.9.2"
}
},
"nbformat": 4,