feat: Add parallel iterators

crates/swc_par_iter/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+description = "Fork of rayon, with chili support"
+edition     = { workspace = true }
+license     = { workspace = true }
+name        = "swc_par_iter"
+repository  = { workspace = true }
+version     = "1.0.0"
+
+[dependencies]
+either       = { workspace = true }
+swc_parallel = { version = "1.3.0", path = "../swc_parallel", default-features = false }
+
+[dev-dependencies]
+chili = { workspace = true }
+rand = { workspace = true }
+rand_xorshift = "0.3"
+swc_parallel = { version = "1.3.0", path = "../swc_parallel", default-features = false, features = [
+    "chili",
+] }

crates/swc_par_iter/src/array.rs

@@ -0,0 +1,87 @@
+//! Parallel iterator types for [arrays] (`[T; N]`)
+//!
+//! You will rarely need to interact with this module directly unless you need
+//! to name one of the iterator types.
+//!
+//! [arrays]: https://doc.rust-lang.org/std/primitive.array.html
+
+use std::mem::ManuallyDrop;
+
+use crate::{
+    iter::{plumbing::*, *},
+    slice::{Iter, IterMut},
+    vec::DrainProducer,
+};
+
+impl<'data, T: Sync + 'data, const N: usize> IntoParallelIterator for &'data [T; N] {
+    type Item = &'data T;
+    type Iter = Iter<'data, T>;
+
+    fn into_par_iter(self) -> Self::Iter {
+        <&[T]>::into_par_iter(self)
+    }
+}
+
+impl<'data, T: Send + 'data, const N: usize> IntoParallelIterator for &'data mut [T; N] {
+    type Item = &'data mut T;
+    type Iter = IterMut<'data, T>;
+
+    fn into_par_iter(self) -> Self::Iter {
+        <&mut [T]>::into_par_iter(self)
+    }
+}
+
+impl<T: Send, const N: usize> IntoParallelIterator for [T; N] {
+    type Item = T;
+    type Iter = IntoIter<T, N>;
+
+    fn into_par_iter(self) -> Self::Iter {
+        IntoIter { array: self }
+    }
+}
+
+/// Parallel iterator that moves out of an array.
+#[derive(Debug, Clone)]
+pub struct IntoIter<T: Send, const N: usize> {
+    array: [T; N],
+}
+
+impl<T: Send, const N: usize> ParallelIterator for IntoIter<T, N> {
+    type Item = T;
+
+    fn drive_unindexed<C>(self, consumer: C) -> C::Result
+    where
+        C: UnindexedConsumer<Self::Item>,
+    {
+        bridge(self, consumer)
+    }
+
+    fn opt_len(&self) -> Option<usize> {
+        Some(N)
+    }
+}
+
+impl<T: Send, const N: usize> IndexedParallelIterator for IntoIter<T, N> {
+    fn drive<C>(self, consumer: C) -> C::Result
+    where
+        C: Consumer<Self::Item>,
+    {
+        bridge(self, consumer)
+    }
+
+    fn len(&self) -> usize {
+        N
+    }
+
+    fn with_producer<CB>(self, callback: CB) -> CB::Output
+    where
+        CB: ProducerCallback<Self::Item>,
+    {
+        unsafe {
+            // Drain every item, and then the local array can just fall out of scope.
+            let mut array = ManuallyDrop::new(self.array);
+            let producer = DrainProducer::new(array.as_mut_slice());
+            callback.callback(producer)
+        }
+    }
+}

crates/swc_par_iter/src/collections/binary_heap.rs

@@ -0,0 +1,122 @@
+//! This module contains the parallel iterator types for heaps
+//! (`BinaryHeap<T>`). You will rarely need to interact with it directly
+//! unless you have need to name one of the iterator types.
+
+use std::collections::BinaryHeap;
+
+use crate::{
+    iter::{plumbing::*, *},
+    vec,
+};
+
+/// Parallel iterator over a binary heap
+#[derive(Debug, Clone)]
+pub struct IntoIter<T: Ord + Send> {
+    inner: vec::IntoIter<T>,
+}
+
+impl<T: Ord + Send> IntoParallelIterator for BinaryHeap<T> {
+    type Item = T;
+    type Iter = IntoIter<T>;
+
+    fn into_par_iter(self) -> Self::Iter {
+        IntoIter {
+            inner: Vec::from(self).into_par_iter(),
+        }
+    }
+}
+
+delegate_indexed_iterator! {
+    IntoIter<T> => T,
+    impl<T: Ord + Send>
+}
+
+/// Parallel iterator over an immutable reference to a binary heap
+#[derive(Debug)]
+pub struct Iter<'a, T: Ord + Sync> {
+    // TODO (MSRV 1.80): this could use `slice::Iter` built from
+    // `BinaryHeap::as_slice`, rather than using a temp `Vec<&T>`.
+    inner: vec::IntoIter<&'a T>,
+}
+
+impl<'a, T: Ord + Sync> Clone for Iter<'a, T> {
+    fn clone(&self) -> Self {
+        Iter {
+            inner: self.inner.clone(),
+        }
+    }
+}
+
+into_par_vec! {
+    &'a BinaryHeap<T> => Iter<'a, T>,
+    impl<'a, T: Ord + Sync>
+}
+
+delegate_indexed_iterator! {
+    Iter<'a, T> => &'a T,
+    impl<'a, T: Ord + Sync + 'a>
+}
+
+// `BinaryHeap` doesn't have a mutable `Iterator`
+
+/// Draining parallel iterator that moves out of a binary heap,
+/// but keeps the total capacity.
+#[derive(Debug)]
+pub struct Drain<'a, T: Ord + Send> {
+    heap: &'a mut BinaryHeap<T>,
+}
+
+impl<'a, T: Ord + Send> ParallelDrainFull for &'a mut BinaryHeap<T> {
+    type Item = T;
+    type Iter = Drain<'a, T>;
+
+    fn par_drain(self) -> Self::Iter {
+        Drain { heap: self }
+    }
+}
+
+impl<'a, T: Ord + Send> ParallelIterator for Drain<'a, T> {
+    type Item = T;
+
+    fn drive_unindexed<C>(self, consumer: C) -> C::Result
+    where
+        C: UnindexedConsumer<Self::Item>,
+    {
+        bridge(self, consumer)
+    }
+
+    fn opt_len(&self) -> Option<usize> {
+        Some(self.len())
+    }
+}
+
+impl<'a, T: Ord + Send> IndexedParallelIterator for Drain<'a, T> {
+    fn drive<C>(self, consumer: C) -> C::Result
+    where
+        C: Consumer<Self::Item>,
+    {
+        bridge(self, consumer)
+    }
+
+    fn len(&self) -> usize {
+        self.heap.len()
+    }
+
+    fn with_producer<CB>(self, callback: CB) -> CB::Output
+    where
+        CB: ProducerCallback<Self::Item>,
+    {
+        super::DrainGuard::new(self.heap)
+            .par_drain(..)
+            .with_producer(callback)
+    }
+}
+
+impl<'a, T: Ord + Send> Drop for Drain<'a, T> {
+    fn drop(&mut self) {
+        if !self.heap.is_empty() {
+            // We must not have produced, so just call a normal drain to remove the items.
+            self.heap.drain();
+        }
+    }
+}

crates/swc_par_iter/src/collections/btree_map.rs

@@ -0,0 +1,66 @@
+//! This module contains the parallel iterator types for B-Tree maps
+//! (`BTreeMap<K, V>`). You will rarely need to interact with it directly
+//! unless you have need to name one of the iterator types.
+
+use std::collections::BTreeMap;
+
+use crate::{
+    iter::{plumbing::*, *},
+    vec,
+};
+
+/// Parallel iterator over a B-Tree map
+#[derive(Debug)] // std doesn't Clone
+pub struct IntoIter<K: Ord + Send, V: Send> {
+    inner: vec::IntoIter<(K, V)>,
+}
+
+into_par_vec! {
+    BTreeMap<K, V> => IntoIter<K, V>,
+    impl<K: Ord + Send, V: Send>
+}
+
+delegate_iterator! {
+    IntoIter<K, V> => (K, V),
+    impl<K: Ord + Send, V: Send>
+}
+
+/// Parallel iterator over an immutable reference to a B-Tree map
+#[derive(Debug)]
+pub struct Iter<'a, K: Ord + Sync, V: Sync> {
+    inner: vec::IntoIter<(&'a K, &'a V)>,
+}
+
+impl<'a, K: Ord + Sync, V: Sync> Clone for Iter<'a, K, V> {
+    fn clone(&self) -> Self {
+        Iter {
+            inner: self.inner.clone(),
+        }
+    }
+}
+
+into_par_vec! {
+    &'a BTreeMap<K, V> => Iter<'a, K, V>,
+    impl<'a, K: Ord + Sync, V: Sync>
+}
+
+delegate_iterator! {
+    Iter<'a, K, V> => (&'a K, &'a V),
+    impl<'a, K: Ord + Sync + 'a, V: Sync + 'a>
+}
+
+/// Parallel iterator over a mutable reference to a B-Tree map
+#[derive(Debug)]
+pub struct IterMut<'a, K: Ord + Sync, V: Send> {
+    inner: vec::IntoIter<(&'a K, &'a mut V)>,
+}
+
+into_par_vec! {
+    &'a mut BTreeMap<K, V> => IterMut<'a, K, V>,
+    impl<'a, K: Ord + Sync, V: Send>
+}
+
+delegate_iterator! {
+    IterMut<'a, K, V> => (&'a K, &'a mut V),
+    impl<'a, K: Ord + Sync + 'a, V: Send + 'a>
+}