1 files changed, 573 insertions, 0 deletions
diff --git a/third_party/rust/rayon/src/iter/map_with.rs b/third_party/rust/rayon/src/iter/map_with.rs
new file mode 100644
index 0000000000..10b1b4caca
--- /dev/null
+++ b/third_party/rust/rayon/src/iter/map_with.rs
@@ -0,0 +1,573 @@
+use super::plumbing::*;
+use super::*;
+
+use std::fmt::{self, Debug};
+
+/// `MapWith` is an iterator that transforms the elements of an underlying iterator.
+///
+/// This struct is created by the [`map_with()`] method on [`ParallelIterator`]
+///
+/// [`map_with()`]: trait.ParallelIterator.html#method.map_with
+/// [`ParallelIterator`]: trait.ParallelIterator.html
+#[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
+#[derive(Clone)]
+pub struct MapWith<I: ParallelIterator, T, F> {
+    base: I,
+    item: T,
+    map_op: F,
+}
+
+impl<I: ParallelIterator + Debug, T: Debug, F> Debug for MapWith<I, T, F> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("MapWith")
+            .field("base", &self.base)
+            .field("item", &self.item)
+            .finish()
+    }
+}
+
+impl<I, T, F> MapWith<I, T, F>
+where
+    I: ParallelIterator,
+{
+    /// Creates a new `MapWith` iterator.
+    pub(super) fn new(base: I, item: T, map_op: F) -> Self {
+        MapWith { base, item, map_op }
+    }
+}
+
+impl<I, T, F, R> ParallelIterator for MapWith<I, T, F>
+where
+    I: ParallelIterator,
+    T: Send + Clone,
+    F: Fn(&mut T, I::Item) -> R + Sync + Send,
+    R: Send,
+{
+    type Item = R;
+
+    fn drive_unindexed<C>(self, consumer: C) -> C::Result
+    where
+        C: UnindexedConsumer<Self::Item>,
+    {
+        let consumer1 = MapWithConsumer::new(consumer, self.item, &self.map_op);
+        self.base.drive_unindexed(consumer1)
+    }
+
+    fn opt_len(&self) -> Option<usize> {
+        self.base.opt_len()
+    }
+}
+
+impl<I, T, F, R> IndexedParallelIterator for MapWith<I, T, F>
+where
+    I: IndexedParallelIterator,
+    T: Send + Clone,
+    F: Fn(&mut T, I::Item) -> R + Sync + Send,
+    R: Send,
+{
+    fn drive<C>(self, consumer: C) -> C::Result
+    where
+        C: Consumer<Self::Item>,
+    {
+        let consumer1 = MapWithConsumer::new(consumer, self.item, &self.map_op);
+        self.base.drive(consumer1)
+    }
+
+    fn len(&self) -> usize {
+        self.base.len()
+    }
+
+    fn with_producer<CB>(self, callback: CB) -> CB::Output
+    where
+        CB: ProducerCallback<Self::Item>,
+    {
+        return self.base.with_producer(Callback {
+            callback,
+            item: self.item,
+            map_op: self.map_op,
+        });
+
+        struct Callback<CB, U, F> {
+            callback: CB,
+            item: U,
+            map_op: F,
+        }
+
+        impl<T, U, F, R, CB> ProducerCallback<T> for Callback<CB, U, F>
+        where
+            CB: ProducerCallback<R>,
+            U: Send + Clone,
+            F: Fn(&mut U, T) -> R + Sync,
+            R: Send,
+        {
+            type Output = CB::Output;
+
+            fn callback<P>(self, base: P) -> CB::Output
+            where
+                P: Producer<Item = T>,
+            {
+                let producer = MapWithProducer {
+                    base,
+                    item: self.item,
+                    map_op: &self.map_op,
+                };
+                self.callback.callback(producer)
+            }
+        }
+    }
+}
+
+/// ////////////////////////////////////////////////////////////////////////
+
+struct MapWithProducer<'f, P, U, F> {
+    base: P,
+    item: U,
+    map_op: &'f F,
+}
+
+impl<'f, P, U, F, R> Producer for MapWithProducer<'f, P, U, F>
+where
+    P: Producer,
+    U: Send + Clone,
+    F: Fn(&mut U, P::Item) -> R + Sync,
+    R: Send,
+{
+    type Item = R;
+    type IntoIter = MapWithIter<'f, P::IntoIter, U, F>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        MapWithIter {
+            base: self.base.into_iter(),
+            item: self.item,
+            map_op: self.map_op,
+        }
+    }
+
+    fn min_len(&self) -> usize {
+        self.base.min_len()
+    }
+    fn max_len(&self) -> usize {
+        self.base.max_len()
+    }
+
+    fn split_at(self, index: usize) -> (Self, Self) {
+        let (left, right) = self.base.split_at(index);
+        (
+            MapWithProducer {
+                base: left,
+                item: self.item.clone(),
+                map_op: self.map_op,
+            },
+            MapWithProducer {
+                base: right,
+                item: self.item,
+                map_op: self.map_op,
+            },
+        )
+    }
+
+    fn fold_with<G>(self, folder: G) -> G
+    where
+        G: Folder<Self::Item>,
+    {
+        let folder1 = MapWithFolder {
+            base: folder,
+            item: self.item,
+            map_op: self.map_op,
+        };
+        self.base.fold_with(folder1).base
+    }
+}
+
+struct MapWithIter<'f, I, U, F> {
+    base: I,
+    item: U,
+    map_op: &'f F,
+}
+
+impl<'f, I, U, F, R> Iterator for MapWithIter<'f, I, U, F>
+where
+    I: Iterator,
+    F: Fn(&mut U, I::Item) -> R + Sync,
+    R: Send,
+{
+    type Item = R;
+
+    fn next(&mut self) -> Option<R> {
+        let item = self.base.next()?;
+        Some((self.map_op)(&mut self.item, item))
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.base.size_hint()
+    }
+}
+
+impl<'f, I, U, F, R> DoubleEndedIterator for MapWithIter<'f, I, U, F>
+where
+    I: DoubleEndedIterator,
+    F: Fn(&mut U, I::Item) -> R + Sync,
+    R: Send,
+{
+    fn next_back(&mut self) -> Option<R> {
+        let item = self.base.next_back()?;
+        Some((self.map_op)(&mut self.item, item))
+    }
+}
+
+impl<'f, I, U, F, R> ExactSizeIterator for MapWithIter<'f, I, U, F>
+where
+    I: ExactSizeIterator,
+    F: Fn(&mut U, I::Item) -> R + Sync,
+    R: Send,
+{
+}
+
+/// ////////////////////////////////////////////////////////////////////////
+/// Consumer implementation
+
+struct MapWithConsumer<'f, C, U, F> {
+    base: C,
+    item: U,
+    map_op: &'f F,
+}
+
+impl<'f, C, U, F> MapWithConsumer<'f, C, U, F> {
+    fn new(base: C, item: U, map_op: &'f F) -> Self {
+        MapWithConsumer { base, item, map_op }
+    }
+}
+
+impl<'f, T, U, R, C, F> Consumer<T> for MapWithConsumer<'f, C, U, F>
+where
+    C: Consumer<R>,
+    U: Send + Clone,
+    F: Fn(&mut U, T) -> R + Sync,
+    R: Send,
+{
+    type Folder = MapWithFolder<'f, C::Folder, U, F>;
+    type Reducer = C::Reducer;
+    type Result = C::Result;
+
+    fn split_at(self, index: usize) -> (Self, Self, Self::Reducer) {
+        let (left, right, reducer) = self.base.split_at(index);
+        (
+            MapWithConsumer::new(left, self.item.clone(), self.map_op),
+            MapWithConsumer::new(right, self.item, self.map_op),
+            reducer,
+        )
+    }
+
+    fn into_folder(self) -> Self::Folder {
+        MapWithFolder {
+            base: self.base.into_folder(),
+            item: self.item,
+            map_op: self.map_op,
+        }
+    }
+
+    fn full(&self) -> bool {
+        self.base.full()
+    }
+}
+
+impl<'f, T, U, R, C, F> UnindexedConsumer<T> for MapWithConsumer<'f, C, U, F>
+where
+    C: UnindexedConsumer<R>,
+    U: Send + Clone,
+    F: Fn(&mut U, T) -> R + Sync,
+    R: Send,
+{
+    fn split_off_left(&self) -> Self {
+        MapWithConsumer::new(self.base.split_off_left(), self.item.clone(), self.map_op)
+    }
+
+    fn to_reducer(&self) -> Self::Reducer {
+        self.base.to_reducer()
+    }
+}
+
+struct MapWithFolder<'f, C, U, F> {
+    base: C,
+    item: U,
+    map_op: &'f F,
+}
+
+impl<'f, T, U, R, C, F> Folder<T> for MapWithFolder<'f, C, U, F>
+where
+    C: Folder<R>,
+    F: Fn(&mut U, T) -> R,
+{
+    type Result = C::Result;
+
+    fn consume(mut self, item: T) -> Self {
+        let mapped_item = (self.map_op)(&mut self.item, item);
+        self.base = self.base.consume(mapped_item);
+        self
+    }
+
+    fn consume_iter<I>(mut self, iter: I) -> Self
+    where
+        I: IntoIterator<Item = T>,
+    {
+        fn with<'f, T, U, R>(
+            item: &'f mut U,
+            map_op: impl Fn(&mut U, T) -> R + 'f,
+        ) -> impl FnMut(T) -> R + 'f {
+            move |x| map_op(item, x)
+        }
+
+        {
+            let mapped_iter = iter.into_iter().map(with(&mut self.item, self.map_op));
+            self.base = self.base.consume_iter(mapped_iter);
+        }
+        self
+    }
+
+    fn complete(self) -> C::Result {
+        self.base.complete()
+    }
+
+    fn full(&self) -> bool {
+        self.base.full()
+    }
+}
+
+// ------------------------------------------------------------------------------------------------
+
+/// `MapInit` is an iterator that transforms the elements of an underlying iterator.
+///
+/// This struct is created by the [`map_init()`] method on [`ParallelIterator`]
+///
+/// [`map_init()`]: trait.ParallelIterator.html#method.map_init
+/// [`ParallelIterator`]: trait.ParallelIterator.html
+#[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
+#[derive(Clone)]
+pub struct MapInit<I: ParallelIterator, INIT, F> {
+    base: I,
+    init: INIT,
+    map_op: F,
+}
+
+impl<I: ParallelIterator + Debug, INIT, F> Debug for MapInit<I, INIT, F> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("MapInit").field("base", &self.base).finish()
+    }
+}
+
+impl<I, INIT, F> MapInit<I, INIT, F>
+where
+    I: ParallelIterator,
+{
+    /// Creates a new `MapInit` iterator.
+    pub(super) fn new(base: I, init: INIT, map_op: F) -> Self {
+        MapInit { base, init, map_op }
+    }
+}
+
+impl<I, INIT, T, F, R> ParallelIterator for MapInit<I, INIT, F>
+where
+    I: ParallelIterator,
+    INIT: Fn() -> T + Sync + Send,
+    F: Fn(&mut T, I::Item) -> R + Sync + Send,
+    R: Send,
+{
+    type Item = R;
+
+    fn drive_unindexed<C>(self, consumer: C) -> C::Result
+    where
+        C: UnindexedConsumer<Self::Item>,
+    {
+        let consumer1 = MapInitConsumer::new(consumer, &self.init, &self.map_op);
+        self.base.drive_unindexed(consumer1)
+    }
+
+    fn opt_len(&self) -> Option<usize> {
+        self.base.opt_len()
+    }
+}
+
+impl<I, INIT, T, F, R> IndexedParallelIterator for MapInit<I, INIT, F>
+where
+    I: IndexedParallelIterator,
+    INIT: Fn() -> T + Sync + Send,
+    F: Fn(&mut T, I::Item) -> R + Sync + Send,
+    R: Send,
+{
+    fn drive<C>(self, consumer: C) -> C::Result
+    where
+        C: Consumer<Self::Item>,
+    {
+        let consumer1 = MapInitConsumer::new(consumer, &self.init, &self.map_op);
+        self.base.drive(consumer1)
+    }
+
+    fn len(&self) -> usize {
+        self.base.len()
+    }
+
+    fn with_producer<CB>(self, callback: CB) -> CB::Output
+    where
+        CB: ProducerCallback<Self::Item>,
+    {
+        return self.base.with_producer(Callback {
+            callback,
+            init: self.init,
+            map_op: self.map_op,
+        });
+
+        struct Callback<CB, INIT, F> {
+            callback: CB,
+            init: INIT,
+            map_op: F,
+        }
+
+        impl<T, INIT, U, F, R, CB> ProducerCallback<T> for Callback<CB, INIT, F>
+        where
+            CB: ProducerCallback<R>,
+            INIT: Fn() -> U + Sync,
+            F: Fn(&mut U, T) -> R + Sync,
+            R: Send,
+        {
+            type Output = CB::Output;
+
+            fn callback<P>(self, base: P) -> CB::Output
+            where
+                P: Producer<Item = T>,
+            {
+                let producer = MapInitProducer {
+                    base,
+                    init: &self.init,
+                    map_op: &self.map_op,
+                };
+                self.callback.callback(producer)
+            }
+        }
+    }
+}
+
+/// ////////////////////////////////////////////////////////////////////////
+
+struct MapInitProducer<'f, P, INIT, F> {
+    base: P,
+    init: &'f INIT,
+    map_op: &'f F,
+}
+
+impl<'f, P, INIT, U, F, R> Producer for MapInitProducer<'f, P, INIT, F>
+where
+    P: Producer,
+    INIT: Fn() -> U + Sync,
+    F: Fn(&mut U, P::Item) -> R + Sync,
+    R: Send,
+{
+    type Item = R;
+    type IntoIter = MapWithIter<'f, P::IntoIter, U, F>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        MapWithIter {
+            base: self.base.into_iter(),
+            item: (self.init)(),
+            map_op: self.map_op,
+        }
+    }
+
+    fn min_len(&self) -> usize {
+        self.base.min_len()
+    }
+    fn max_len(&self) -> usize {
+        self.base.max_len()
+    }
+
+    fn split_at(self, index: usize) -> (Self, Self) {
+        let (left, right) = self.base.split_at(index);
+        (
+            MapInitProducer {
+                base: left,
+                init: self.init,
+                map_op: self.map_op,
+            },
+            MapInitProducer {
+                base: right,
+                init: self.init,
+                map_op: self.map_op,
+            },
+        )
+    }
+
+    fn fold_with<G>(self, folder: G) -> G
+    where
+        G: Folder<Self::Item>,
+    {
+        let folder1 = MapWithFolder {
+            base: folder,
+            item: (self.init)(),
+            map_op: self.map_op,
+        };
+        self.base.fold_with(folder1).base
+    }
+}
+
+/// ////////////////////////////////////////////////////////////////////////
+/// Consumer implementation
+
+struct MapInitConsumer<'f, C, INIT, F> {
+    base: C,
+    init: &'f INIT,
+    map_op: &'f F,
+}
+
+impl<'f, C, INIT, F> MapInitConsumer<'f, C, INIT, F> {
+    fn new(base: C, init: &'f INIT, map_op: &'f F) -> Self {
+        MapInitConsumer { base, init, map_op }
+    }
+}
+
+impl<'f, T, INIT, U, R, C, F> Consumer<T> for MapInitConsumer<'f, C, INIT, F>
+where
+    C: Consumer<R>,
+    INIT: Fn() -> U + Sync,
+    F: Fn(&mut U, T) -> R + Sync,
+    R: Send,
+{
+    type Folder = MapWithFolder<'f, C::Folder, U, F>;
+    type Reducer = C::Reducer;
+    type Result = C::Result;
+
+    fn split_at(self, index: usize) -> (Self, Self, Self::Reducer) {
+        let (left, right, reducer) = self.base.split_at(index);
+        (
+            MapInitConsumer::new(left, self.init, self.map_op),
+            MapInitConsumer::new(right, self.init, self.map_op),
+            reducer,
+        )
+    }
+
+    fn into_folder(self) -> Self::Folder {
+        MapWithFolder {
+            base: self.base.into_folder(),
+            item: (self.init)(),
+            map_op: self.map_op,
+        }
+    }
+
+    fn full(&self) -> bool {
+        self.base.full()
+    }
+}
+
+impl<'f, T, INIT, U, R, C, F> UnindexedConsumer<T> for MapInitConsumer<'f, C, INIT, F>
+where
+    C: UnindexedConsumer<R>,
+    INIT: Fn() -> U + Sync,
+    F: Fn(&mut U, T) -> R + Sync,
+    R: Send,
+{
+    fn split_off_left(&self) -> Self {
+        MapInitConsumer::new(self.base.split_off_left(), self.init, self.map_op)
+    }
+
+    fn to_reducer(&self) -> Self::Reducer {
+        self.base.to_reducer()
+    }
+}