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Diffstat (limited to 'vendor/rayon/src/iter/intersperse.rs')
-rw-r--r-- | vendor/rayon/src/iter/intersperse.rs | 410 |
1 files changed, 0 insertions, 410 deletions
diff --git a/vendor/rayon/src/iter/intersperse.rs b/vendor/rayon/src/iter/intersperse.rs deleted file mode 100644 index 798bdc1..0000000 --- a/vendor/rayon/src/iter/intersperse.rs +++ /dev/null @@ -1,410 +0,0 @@ -use super::plumbing::*; -use super::*; -use std::cell::Cell; -use std::iter::{self, Fuse}; - -/// `Intersperse` is an iterator that inserts a particular item between each -/// item of the adapted iterator. This struct is created by the -/// [`intersperse()`] method on [`ParallelIterator`] -/// -/// [`intersperse()`]: trait.ParallelIterator.html#method.intersperse -/// [`ParallelIterator`]: trait.ParallelIterator.html -#[must_use = "iterator adaptors are lazy and do nothing unless consumed"] -#[derive(Clone, Debug)] -pub struct Intersperse<I> -where - I: ParallelIterator, - I::Item: Clone, -{ - base: I, - item: I::Item, -} - -impl<I> Intersperse<I> -where - I: ParallelIterator, - I::Item: Clone, -{ - /// Creates a new `Intersperse` iterator - pub(super) fn new(base: I, item: I::Item) -> Self { - Intersperse { base, item } - } -} - -impl<I> ParallelIterator for Intersperse<I> -where - I: ParallelIterator, - I::Item: Clone + Send, -{ - type Item = I::Item; - - fn drive_unindexed<C>(self, consumer: C) -> C::Result - where - C: UnindexedConsumer<I::Item>, - { - let consumer1 = IntersperseConsumer::new(consumer, self.item); - self.base.drive_unindexed(consumer1) - } - - fn opt_len(&self) -> Option<usize> { - match self.base.opt_len()? { - 0 => Some(0), - len => len.checked_add(len - 1), - } - } -} - -impl<I> IndexedParallelIterator for Intersperse<I> -where - I: IndexedParallelIterator, - I::Item: Clone + Send, -{ - fn drive<C>(self, consumer: C) -> C::Result - where - C: Consumer<Self::Item>, - { - let consumer1 = IntersperseConsumer::new(consumer, self.item); - self.base.drive(consumer1) - } - - fn len(&self) -> usize { - let len = self.base.len(); - if len > 0 { - len.checked_add(len - 1).expect("overflow") - } else { - 0 - } - } - - fn with_producer<CB>(self, callback: CB) -> CB::Output - where - CB: ProducerCallback<Self::Item>, - { - let len = self.len(); - return self.base.with_producer(Callback { - callback, - item: self.item, - len, - }); - - struct Callback<CB, T> { - callback: CB, - item: T, - len: usize, - } - - impl<T, CB> ProducerCallback<T> for Callback<CB, T> - where - CB: ProducerCallback<T>, - T: Clone + Send, - { - type Output = CB::Output; - - fn callback<P>(self, base: P) -> CB::Output - where - P: Producer<Item = T>, - { - let producer = IntersperseProducer::new(base, self.item, self.len); - self.callback.callback(producer) - } - } - } -} - -struct IntersperseProducer<P> -where - P: Producer, -{ - base: P, - item: P::Item, - len: usize, - clone_first: bool, -} - -impl<P> IntersperseProducer<P> -where - P: Producer, -{ - fn new(base: P, item: P::Item, len: usize) -> Self { - IntersperseProducer { - base, - item, - len, - clone_first: false, - } - } -} - -impl<P> Producer for IntersperseProducer<P> -where - P: Producer, - P::Item: Clone + Send, -{ - type Item = P::Item; - type IntoIter = IntersperseIter<P::IntoIter>; - - fn into_iter(self) -> Self::IntoIter { - IntersperseIter { - base: self.base.into_iter().fuse(), - item: self.item, - clone_first: self.len > 0 && self.clone_first, - - // If there's more than one item, then even lengths end the opposite - // of how they started with respect to interspersed clones. - clone_last: self.len > 1 && ((self.len & 1 == 0) ^ self.clone_first), - } - } - - 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) { - debug_assert!(index <= self.len); - - // The left needs half of the items from the base producer, and the - // other half will be our interspersed item. If we're not leading with - // a cloned item, then we need to round up the base number of items, - // otherwise round down. - let base_index = (index + !self.clone_first as usize) / 2; - let (left_base, right_base) = self.base.split_at(base_index); - - let left = IntersperseProducer { - base: left_base, - item: self.item.clone(), - len: index, - clone_first: self.clone_first, - }; - - let right = IntersperseProducer { - base: right_base, - item: self.item, - len: self.len - index, - - // If the index is odd, the right side toggles `clone_first`. - clone_first: (index & 1 == 1) ^ self.clone_first, - }; - - (left, right) - } - - fn fold_with<F>(self, folder: F) -> F - where - F: Folder<Self::Item>, - { - let folder1 = IntersperseFolder { - base: folder, - item: self.item, - clone_first: self.clone_first, - }; - self.base.fold_with(folder1).base - } -} - -struct IntersperseIter<I> -where - I: Iterator, -{ - base: Fuse<I>, - item: I::Item, - clone_first: bool, - clone_last: bool, -} - -impl<I> Iterator for IntersperseIter<I> -where - I: DoubleEndedIterator + ExactSizeIterator, - I::Item: Clone, -{ - type Item = I::Item; - - fn next(&mut self) -> Option<Self::Item> { - if self.clone_first { - self.clone_first = false; - Some(self.item.clone()) - } else if let next @ Some(_) = self.base.next() { - // If there are any items left, we'll need another clone in front. - self.clone_first = self.base.len() != 0; - next - } else if self.clone_last { - self.clone_last = false; - Some(self.item.clone()) - } else { - None - } - } - - fn size_hint(&self) -> (usize, Option<usize>) { - let len = self.len(); - (len, Some(len)) - } -} - -impl<I> DoubleEndedIterator for IntersperseIter<I> -where - I: DoubleEndedIterator + ExactSizeIterator, - I::Item: Clone, -{ - fn next_back(&mut self) -> Option<Self::Item> { - if self.clone_last { - self.clone_last = false; - Some(self.item.clone()) - } else if let next_back @ Some(_) = self.base.next_back() { - // If there are any items left, we'll need another clone in back. - self.clone_last = self.base.len() != 0; - next_back - } else if self.clone_first { - self.clone_first = false; - Some(self.item.clone()) - } else { - None - } - } -} - -impl<I> ExactSizeIterator for IntersperseIter<I> -where - I: DoubleEndedIterator + ExactSizeIterator, - I::Item: Clone, -{ - fn len(&self) -> usize { - let len = self.base.len(); - len + len.saturating_sub(1) + self.clone_first as usize + self.clone_last as usize - } -} - -struct IntersperseConsumer<C, T> { - base: C, - item: T, - clone_first: Cell<bool>, -} - -impl<C, T> IntersperseConsumer<C, T> -where - C: Consumer<T>, -{ - fn new(base: C, item: T) -> Self { - IntersperseConsumer { - base, - item, - clone_first: false.into(), - } - } -} - -impl<C, T> Consumer<T> for IntersperseConsumer<C, T> -where - C: Consumer<T>, - T: Clone + Send, -{ - type Folder = IntersperseFolder<C::Folder, T>; - type Reducer = C::Reducer; - type Result = C::Result; - - fn split_at(mut self, index: usize) -> (Self, Self, Self::Reducer) { - // We'll feed twice as many items to the base consumer, except if we're - // not currently leading with a cloned item, then it's one less. - let base_index = index + index.saturating_sub(!self.clone_first.get() as usize); - let (left, right, reducer) = self.base.split_at(base_index); - - let right = IntersperseConsumer { - base: right, - item: self.item.clone(), - clone_first: true.into(), - }; - self.base = left; - (self, right, reducer) - } - - fn into_folder(self) -> Self::Folder { - IntersperseFolder { - base: self.base.into_folder(), - item: self.item, - clone_first: self.clone_first.get(), - } - } - - fn full(&self) -> bool { - self.base.full() - } -} - -impl<C, T> UnindexedConsumer<T> for IntersperseConsumer<C, T> -where - C: UnindexedConsumer<T>, - T: Clone + Send, -{ - fn split_off_left(&self) -> Self { - let left = IntersperseConsumer { - base: self.base.split_off_left(), - item: self.item.clone(), - clone_first: self.clone_first.clone(), - }; - self.clone_first.set(true); - left - } - - fn to_reducer(&self) -> Self::Reducer { - self.base.to_reducer() - } -} - -struct IntersperseFolder<C, T> { - base: C, - item: T, - clone_first: bool, -} - -impl<C, T> Folder<T> for IntersperseFolder<C, T> -where - C: Folder<T>, - T: Clone, -{ - type Result = C::Result; - - fn consume(mut self, item: T) -> Self { - if self.clone_first { - self.base = self.base.consume(self.item.clone()); - if self.base.full() { - return self; - } - } else { - self.clone_first = true; - } - self.base = self.base.consume(item); - self - } - - fn consume_iter<I>(self, iter: I) -> Self - where - I: IntoIterator<Item = T>, - { - let mut clone_first = self.clone_first; - let between_item = self.item; - let base = self.base.consume_iter(iter.into_iter().flat_map(|item| { - let first = if clone_first { - Some(between_item.clone()) - } else { - clone_first = true; - None - }; - first.into_iter().chain(iter::once(item)) - })); - IntersperseFolder { - base, - item: between_item, - clone_first, - } - } - - fn complete(self) -> C::Result { - self.base.complete() - } - - fn full(&self) -> bool { - self.base.full() - } -} |