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-rw-r--r--src/iter/try_fold.rs294
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diff --git a/src/iter/try_fold.rs b/src/iter/try_fold.rs
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+use super::plumbing::*;
+use super::*;
+
+use super::private::Try;
+use std::fmt::{self, Debug};
+use std::marker::PhantomData;
+
+impl<U, I, ID, F> TryFold<I, U, ID, F>
+where
+ I: ParallelIterator,
+ F: Fn(U::Ok, I::Item) -> U + Sync + Send,
+ ID: Fn() -> U::Ok + 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::Ok, I::Item) -> U + Sync + Send,
+ ID: Fn() -> U::Ok + 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::Ok, T) -> U + Sync,
+ ID: Fn() -> U::Ok + 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(),
+ result: Ok((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::Ok, T) -> U + Sync,
+ ID: Fn() -> U::Ok + 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,
+ result: Result<U::Ok, U::Error>,
+}
+
+impl<'r, C, U, F, T> Folder<T> for TryFoldFolder<'r, C, U, F>
+where
+ C: Folder<U>,
+ F: Fn(U::Ok, T) -> U + Sync,
+ U: Try,
+{
+ type Result = C::Result;
+
+ fn consume(mut self, item: T) -> Self {
+ let fold_op = self.fold_op;
+ if let Ok(acc) = self.result {
+ self.result = fold_op(acc, item).into_result();
+ }
+ self
+ }
+
+ fn complete(self) -> C::Result {
+ let item = match self.result {
+ Ok(ok) => U::from_ok(ok),
+ Err(error) => U::from_error(error),
+ };
+ self.base.consume(item).complete()
+ }
+
+ fn full(&self) -> bool {
+ self.result.is_err() || self.base.full()
+ }
+}
+
+// ///////////////////////////////////////////////////////////////////////////
+
+impl<U, I, F> TryFoldWith<I, U, F>
+where
+ I: ParallelIterator,
+ F: Fn(U::Ok, I::Item) -> U + Sync,
+ U: Try + Send,
+ U::Ok: Clone + Send,
+{
+ pub(super) fn new(base: I, item: U::Ok, 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::Ok,
+ fold_op: F,
+}
+
+impl<I: ParallelIterator + Debug, U: Try, F> Debug for TryFoldWith<I, U, F>
+where
+ U::Ok: 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::Ok, I::Item) -> U + Sync + Send,
+ U: Try + Send,
+ U::Ok: 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::Ok,
+ 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::Ok, T) -> U + Sync,
+ U: Try + Send,
+ U::Ok: 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(),
+ result: Ok(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::Ok, T) -> U + Sync,
+ U: Try + Send,
+ U::Ok: 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()
+ }
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-05 23:12:33 +0000