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Diffstat (limited to 'vendor/rayon/src/iter/try_fold.rs')
-rw-r--r-- | vendor/rayon/src/iter/try_fold.rs | 298 |
1 files changed, 298 insertions, 0 deletions
diff --git a/vendor/rayon/src/iter/try_fold.rs b/vendor/rayon/src/iter/try_fold.rs new file mode 100644 index 0000000..6d1048d --- /dev/null +++ b/vendor/rayon/src/iter/try_fold.rs @@ -0,0 +1,298 @@ +use super::plumbing::*; +use super::ParallelIterator; +use super::Try; + +use std::fmt::{self, Debug}; +use std::marker::PhantomData; +use std::ops::ControlFlow::{self, Break, Continue}; + +impl<U, I, ID, F> TryFold<I, U, ID, F> +where + I: ParallelIterator, + F: Fn(U::Output, I::Item) -> U + Sync + Send, + ID: Fn() -> U::Output + Sync + Send, + U: Try + Send, +{ + pub(super) fn new(base: I, identity: ID, fold_op: F) -> Self { + TryFold { + base, + identity, + fold_op, + marker: PhantomData, + } + } +} + +/// `TryFold` is an iterator that applies a function over an iterator producing a single value. +/// This struct is created by the [`try_fold()`] method on [`ParallelIterator`] +/// +/// [`try_fold()`]: trait.ParallelIterator.html#method.try_fold +/// [`ParallelIterator`]: trait.ParallelIterator.html +#[must_use = "iterator adaptors are lazy and do nothing unless consumed"] +#[derive(Clone)] +pub struct TryFold<I, U, ID, F> { + base: I, + identity: ID, + fold_op: F, + marker: PhantomData<U>, +} + +impl<U, I: ParallelIterator + Debug, ID, F> Debug for TryFold<I, U, ID, F> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("TryFold").field("base", &self.base).finish() + } +} + +impl<U, I, ID, F> ParallelIterator for TryFold<I, U, ID, F> +where + I: ParallelIterator, + F: Fn(U::Output, I::Item) -> U + Sync + Send, + ID: Fn() -> U::Output + Sync + Send, + U: Try + Send, +{ + type Item = U; + + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: UnindexedConsumer<Self::Item>, + { + let consumer1 = TryFoldConsumer { + base: consumer, + identity: &self.identity, + fold_op: &self.fold_op, + marker: PhantomData, + }; + self.base.drive_unindexed(consumer1) + } +} + +struct TryFoldConsumer<'c, U, C, ID, F> { + base: C, + identity: &'c ID, + fold_op: &'c F, + marker: PhantomData<U>, +} + +impl<'r, U, T, C, ID, F> Consumer<T> for TryFoldConsumer<'r, U, C, ID, F> +where + C: Consumer<U>, + F: Fn(U::Output, T) -> U + Sync, + ID: Fn() -> U::Output + Sync, + U: Try + Send, +{ + type Folder = TryFoldFolder<'r, 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); + ( + TryFoldConsumer { base: left, ..self }, + TryFoldConsumer { + base: right, + ..self + }, + reducer, + ) + } + + fn into_folder(self) -> Self::Folder { + TryFoldFolder { + base: self.base.into_folder(), + control: Continue((self.identity)()), + fold_op: self.fold_op, + } + } + + fn full(&self) -> bool { + self.base.full() + } +} + +impl<'r, U, T, C, ID, F> UnindexedConsumer<T> for TryFoldConsumer<'r, U, C, ID, F> +where + C: UnindexedConsumer<U>, + F: Fn(U::Output, T) -> U + Sync, + ID: Fn() -> U::Output + Sync, + U: Try + Send, +{ + fn split_off_left(&self) -> Self { + TryFoldConsumer { + base: self.base.split_off_left(), + ..*self + } + } + + fn to_reducer(&self) -> Self::Reducer { + self.base.to_reducer() + } +} + +struct TryFoldFolder<'r, C, U: Try, F> { + base: C, + fold_op: &'r F, + control: ControlFlow<U::Residual, U::Output>, +} + +impl<'r, C, U, F, T> Folder<T> for TryFoldFolder<'r, C, U, F> +where + C: Folder<U>, + F: Fn(U::Output, T) -> U + Sync, + U: Try, +{ + type Result = C::Result; + + fn consume(mut self, item: T) -> Self { + let fold_op = self.fold_op; + if let Continue(acc) = self.control { + self.control = fold_op(acc, item).branch(); + } + self + } + + fn complete(self) -> C::Result { + let item = match self.control { + Continue(c) => U::from_output(c), + Break(r) => U::from_residual(r), + }; + self.base.consume(item).complete() + } + + fn full(&self) -> bool { + match self.control { + Break(_) => true, + _ => self.base.full(), + } + } +} + +// /////////////////////////////////////////////////////////////////////////// + +impl<U, I, F> TryFoldWith<I, U, F> +where + I: ParallelIterator, + F: Fn(U::Output, I::Item) -> U + Sync, + U: Try + Send, + U::Output: Clone + Send, +{ + pub(super) fn new(base: I, item: U::Output, fold_op: F) -> Self { + TryFoldWith { + base, + item, + fold_op, + } + } +} + +/// `TryFoldWith` is an iterator that applies a function over an iterator producing a single value. +/// This struct is created by the [`try_fold_with()`] method on [`ParallelIterator`] +/// +/// [`try_fold_with()`]: trait.ParallelIterator.html#method.try_fold_with +/// [`ParallelIterator`]: trait.ParallelIterator.html +#[must_use = "iterator adaptors are lazy and do nothing unless consumed"] +#[derive(Clone)] +pub struct TryFoldWith<I, U: Try, F> { + base: I, + item: U::Output, + fold_op: F, +} + +impl<I: ParallelIterator + Debug, U: Try, F> Debug for TryFoldWith<I, U, F> +where + U::Output: Debug, +{ + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("TryFoldWith") + .field("base", &self.base) + .field("item", &self.item) + .finish() + } +} + +impl<U, I, F> ParallelIterator for TryFoldWith<I, U, F> +where + I: ParallelIterator, + F: Fn(U::Output, I::Item) -> U + Sync + Send, + U: Try + Send, + U::Output: Clone + Send, +{ + type Item = U; + + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: UnindexedConsumer<Self::Item>, + { + let consumer1 = TryFoldWithConsumer { + base: consumer, + item: self.item, + fold_op: &self.fold_op, + }; + self.base.drive_unindexed(consumer1) + } +} + +struct TryFoldWithConsumer<'c, C, U: Try, F> { + base: C, + item: U::Output, + fold_op: &'c F, +} + +impl<'r, U, T, C, F> Consumer<T> for TryFoldWithConsumer<'r, C, U, F> +where + C: Consumer<U>, + F: Fn(U::Output, T) -> U + Sync, + U: Try + Send, + U::Output: Clone + Send, +{ + type Folder = TryFoldFolder<'r, 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); + ( + TryFoldWithConsumer { + base: left, + item: self.item.clone(), + ..self + }, + TryFoldWithConsumer { + base: right, + ..self + }, + reducer, + ) + } + + fn into_folder(self) -> Self::Folder { + TryFoldFolder { + base: self.base.into_folder(), + control: Continue(self.item), + fold_op: self.fold_op, + } + } + + fn full(&self) -> bool { + self.base.full() + } +} + +impl<'r, U, T, C, F> UnindexedConsumer<T> for TryFoldWithConsumer<'r, C, U, F> +where + C: UnindexedConsumer<U>, + F: Fn(U::Output, T) -> U + Sync, + U: Try + Send, + U::Output: Clone + Send, +{ + fn split_off_left(&self) -> Self { + TryFoldWithConsumer { + base: self.base.split_off_left(), + item: self.item.clone(), + ..*self + } + } + + fn to_reducer(&self) -> Self::Reducer { + self.base.to_reducer() + } +} |