diff options
Diffstat (limited to 'vendor/rayon/src/iter/flat_map_iter.rs')
-rw-r--r-- | vendor/rayon/src/iter/flat_map_iter.rs | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/vendor/rayon/src/iter/flat_map_iter.rs b/vendor/rayon/src/iter/flat_map_iter.rs new file mode 100644 index 0000000..c76cf68 --- /dev/null +++ b/vendor/rayon/src/iter/flat_map_iter.rs @@ -0,0 +1,147 @@ +use super::plumbing::*; +use super::*; + +use std::fmt::{self, Debug}; + +/// `FlatMapIter` maps each element to a serial iterator, then flattens these iterators together. +/// This struct is created by the [`flat_map_iter()`] method on [`ParallelIterator`] +/// +/// [`flat_map_iter()`]: trait.ParallelIterator.html#method.flat_map_iter +/// [`ParallelIterator`]: trait.ParallelIterator.html +#[must_use = "iterator adaptors are lazy and do nothing unless consumed"] +#[derive(Clone)] +pub struct FlatMapIter<I: ParallelIterator, F> { + base: I, + map_op: F, +} + +impl<I: ParallelIterator + Debug, F> Debug for FlatMapIter<I, F> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("FlatMapIter") + .field("base", &self.base) + .finish() + } +} + +impl<I: ParallelIterator, F> FlatMapIter<I, F> { + /// Creates a new `FlatMapIter` iterator. + pub(super) fn new(base: I, map_op: F) -> Self { + FlatMapIter { base, map_op } + } +} + +impl<I, F, SI> ParallelIterator for FlatMapIter<I, F> +where + I: ParallelIterator, + F: Fn(I::Item) -> SI + Sync + Send, + SI: IntoIterator, + SI::Item: Send, +{ + type Item = SI::Item; + + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: UnindexedConsumer<Self::Item>, + { + let consumer = FlatMapIterConsumer::new(consumer, &self.map_op); + self.base.drive_unindexed(consumer) + } +} + +/// //////////////////////////////////////////////////////////////////////// +/// Consumer implementation + +struct FlatMapIterConsumer<'f, C, F> { + base: C, + map_op: &'f F, +} + +impl<'f, C, F> FlatMapIterConsumer<'f, C, F> { + fn new(base: C, map_op: &'f F) -> Self { + FlatMapIterConsumer { base, map_op } + } +} + +impl<'f, T, U, C, F> Consumer<T> for FlatMapIterConsumer<'f, C, F> +where + C: UnindexedConsumer<U::Item>, + F: Fn(T) -> U + Sync, + U: IntoIterator, +{ + type Folder = FlatMapIterFolder<'f, C::Folder, F>; + type Reducer = C::Reducer; + type Result = C::Result; + + fn split_at(self, index: usize) -> (Self, Self, C::Reducer) { + let (left, right, reducer) = self.base.split_at(index); + ( + FlatMapIterConsumer::new(left, self.map_op), + FlatMapIterConsumer::new(right, self.map_op), + reducer, + ) + } + + fn into_folder(self) -> Self::Folder { + FlatMapIterFolder { + base: self.base.into_folder(), + map_op: self.map_op, + } + } + + fn full(&self) -> bool { + self.base.full() + } +} + +impl<'f, T, U, C, F> UnindexedConsumer<T> for FlatMapIterConsumer<'f, C, F> +where + C: UnindexedConsumer<U::Item>, + F: Fn(T) -> U + Sync, + U: IntoIterator, +{ + fn split_off_left(&self) -> Self { + FlatMapIterConsumer::new(self.base.split_off_left(), self.map_op) + } + + fn to_reducer(&self) -> Self::Reducer { + self.base.to_reducer() + } +} + +struct FlatMapIterFolder<'f, C, F> { + base: C, + map_op: &'f F, +} + +impl<'f, T, U, C, F> Folder<T> for FlatMapIterFolder<'f, C, F> +where + C: Folder<U::Item>, + F: Fn(T) -> U, + U: IntoIterator, +{ + type Result = C::Result; + + fn consume(self, item: T) -> Self { + let map_op = self.map_op; + let base = self.base.consume_iter(map_op(item)); + FlatMapIterFolder { base, map_op } + } + + fn consume_iter<I>(self, iter: I) -> Self + where + I: IntoIterator<Item = T>, + { + let map_op = self.map_op; + let iter = iter.into_iter().flat_map(map_op); + let base = self.base.consume_iter(iter); + FlatMapIterFolder { base, map_op } + } + + fn complete(self) -> Self::Result { + self.base.complete() + } + + fn full(&self) -> bool { + self.base.full() + } +} |