Skip to content

Add itertool.combinations.__reduce__ method #3931

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
youknowone merged 1 commit into from
Nov 18, 2022
Merged

Add itertool.combinations.__reduce__ method #3931

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Add itertool.combinations.__reduce__ method 
Add result in struct PyItertoolsCombinations
  • Loading branch information
@seryoungshim17 @youknowone
seryoungshim17 authored and youknowone committed Nov 11, 2022
commit 5608808d0fb8c121591c3a986ba716e0581843c7
101 changes: 74 additions & 27 deletions vm/src/stdlib/itertools.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1308,6 +1308,7 @@ mod decl {
struct PyItertoolsCombinations {
pool: Vec<PyObjectRef>,
indices: PyRwLock<Vec<usize>>,
result: PyRwLock<Option<Vec<usize>>>,
r: AtomicCell<usize>,
exhausted: AtomicCell<bool>,
}
Expand Down Expand Up @@ -1341,6 +1342,7 @@ mod decl {
PyItertoolsCombinations {
pool,
indices: PyRwLock::new((0..r).collect()),
result: PyRwLock::new(None),
r: AtomicCell::new(r),
exhausted: AtomicCell::new(r > n),
}
Expand All @@ -1350,7 +1352,39 @@ mod decl {
}

#[pyclass(with(IterNext, Constructor))]
impl PyItertoolsCombinations {}
impl PyItertoolsCombinations {
#[pymethod(magic)]
fn reduce(zelf: PyRef<Self>, vm: &VirtualMachine) -> PyTupleRef {
let result = zelf.result.read();
if let Some(result) = &*result {
if zelf.exhausted.load() {
vm.new_tuple((
zelf.class().to_owned(),
vm.new_tuple((vm.new_tuple(()), vm.ctx.new_int(zelf.r.load()))),
))
} else {
vm.new_tuple((
zelf.class().to_owned(),
vm.new_tuple((
vm.new_tuple(zelf.pool.clone()),
vm.ctx.new_int(zelf.r.load()),
)),
vm.ctx
.new_tuple(result.iter().map(|&i| zelf.pool[i].clone()).collect()),
))
}
} else {
vm.new_tuple((
zelf.class().to_owned(),
vm.new_tuple((
vm.new_tuple(zelf.pool.clone()),
vm.ctx.new_int(zelf.r.load()),
)),
))
}
}
}

impl IterNextIterable for PyItertoolsCombinations {}
impl IterNext for PyItertoolsCombinations {
fn next(zelf: &Py<Self>, vm: &VirtualMachine) -> PyResult<PyIterReturn> {
Expand All @@ -1367,38 +1401,51 @@ mod decl {
return Ok(PyIterReturn::Return(vm.new_tuple(()).into()));
}

let res = vm.ctx.new_tuple(
zelf.indices
.read()
.iter()
.map(|&i| zelf.pool[i].clone())
.collect(),
);
let mut result = zelf.result.write();

let mut indices = zelf.indices.write();
if let Some(ref mut result) = *result {
let mut indices = zelf.indices.write();

// Scan indices right-to-left until finding one that is not at its maximum (i + n - r).
let mut idx = r as isize - 1;
while idx >= 0 && indices[idx as usize] == idx as usize + n - r {
idx -= 1;
}
// Scan indices right-to-left until finding one that is not at its maximum (i + n - r).
let mut idx = r as isize - 1;
while idx >= 0 && indices[idx as usize] == idx as usize + n - r {
idx -= 1;
}

// If no suitable index is found, then the indices are all at
// their maximum value and we're done.
if idx < 0 {
zelf.exhausted.store(true);
} else {
// Increment the current index which we know is not at its
// maximum. Then move back to the right setting each index
// to its lowest possible value (one higher than the index
// to its left -- this maintains the sort order invariant).
indices[idx as usize] += 1;
for j in idx as usize + 1..r {
indices[j] = indices[j - 1] + 1;
// If no suitable index is found, then the indices are all at
// their maximum value and we're done.
if idx < 0 {
zelf.exhausted.store(true);
return Ok(PyIterReturn::StopIteration(None));
} else {
// Increment the current index which we know is not at its
// maximum. Then move back to the right setting each index
// to its lowest possible value (one higher than the index
// to its left -- this maintains the sort order invariant).
indices[idx as usize] += 1;
for j in idx as usize + 1..r {
indices[j] = indices[j - 1] + 1;
}
for j in 0..r {
result[j] = indices[j];
}
}
} else {
*result = Some((0..r).collect());
}

Ok(PyIterReturn::Return(res.into()))
Ok(PyIterReturn::Return(
vm.ctx
.new_tuple(
result
.as_ref()
.unwrap()
.iter()
.map(|&i| zelf.pool[i].clone())
.collect(),
)
.into(),
))
}
}

Expand Down