| use super::plumbing::*; |
| use super::*; |
| use std::cmp; |
| |
| /// `MinLen` is an iterator that imposes a minimum length on iterator splits. |
| /// This struct is created by the [`with_min_len()`] method on [`IndexedParallelIterator`] |
| /// |
| /// [`with_min_len()`]: trait.IndexedParallelIterator.html#method.with_min_len |
| /// [`IndexedParallelIterator`]: trait.IndexedParallelIterator.html |
| #[must_use = "iterator adaptors are lazy and do nothing unless consumed"] |
| #[derive(Debug, Clone)] |
| pub struct MinLen<I: IndexedParallelIterator> { |
| base: I, |
| min: usize, |
| } |
| |
| impl<I> MinLen<I> |
| where |
| I: IndexedParallelIterator, |
| { |
| /// Creates a new `MinLen` iterator. |
| pub(super) fn new(base: I, min: usize) -> Self { |
| MinLen { base, min } |
| } |
| } |
| |
| impl<I> ParallelIterator for MinLen<I> |
| where |
| I: IndexedParallelIterator, |
| { |
| type Item = I::Item; |
| |
| fn drive_unindexed<C>(self, consumer: C) -> C::Result |
| where |
| C: UnindexedConsumer<Self::Item>, |
| { |
| bridge(self, consumer) |
| } |
| |
| fn opt_len(&self) -> Option<usize> { |
| Some(self.len()) |
| } |
| } |
| |
| impl<I> IndexedParallelIterator for MinLen<I> |
| where |
| I: IndexedParallelIterator, |
| { |
| fn drive<C: Consumer<Self::Item>>(self, consumer: C) -> C::Result { |
| bridge(self, consumer) |
| } |
| |
| 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, |
| min: self.min, |
| }); |
| |
| struct Callback<CB> { |
| callback: CB, |
| min: usize, |
| } |
| |
| impl<T, CB> ProducerCallback<T> for Callback<CB> |
| where |
| CB: ProducerCallback<T>, |
| { |
| type Output = CB::Output; |
| fn callback<P>(self, base: P) -> CB::Output |
| where |
| P: Producer<Item = T>, |
| { |
| let producer = MinLenProducer { |
| base, |
| min: self.min, |
| }; |
| self.callback.callback(producer) |
| } |
| } |
| } |
| } |
| |
| /// //////////////////////////////////////////////////////////////////////// |
| /// `MinLenProducer` implementation |
| |
| struct MinLenProducer<P> { |
| base: P, |
| min: usize, |
| } |
| |
| impl<P> Producer for MinLenProducer<P> |
| where |
| P: Producer, |
| { |
| type Item = P::Item; |
| type IntoIter = P::IntoIter; |
| |
| fn into_iter(self) -> Self::IntoIter { |
| self.base.into_iter() |
| } |
| |
| fn min_len(&self) -> usize { |
| cmp::max(self.min, 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); |
| ( |
| MinLenProducer { |
| base: left, |
| min: self.min, |
| }, |
| MinLenProducer { |
| base: right, |
| min: self.min, |
| }, |
| ) |
| } |
| |
| fn fold_with<F>(self, folder: F) -> F |
| where |
| F: Folder<Self::Item>, |
| { |
| self.base.fold_with(folder) |
| } |
| } |
| |
| /// `MaxLen` is an iterator that imposes a maximum length on iterator splits. |
| /// This struct is created by the [`with_max_len()`] method on [`IndexedParallelIterator`] |
| /// |
| /// [`with_max_len()`]: trait.IndexedParallelIterator.html#method.with_max_len |
| /// [`IndexedParallelIterator`]: trait.IndexedParallelIterator.html |
| #[must_use = "iterator adaptors are lazy and do nothing unless consumed"] |
| #[derive(Debug, Clone)] |
| pub struct MaxLen<I: IndexedParallelIterator> { |
| base: I, |
| max: usize, |
| } |
| |
| impl<I> MaxLen<I> |
| where |
| I: IndexedParallelIterator, |
| { |
| /// Creates a new `MaxLen` iterator. |
| pub(super) fn new(base: I, max: usize) -> Self { |
| MaxLen { base, max } |
| } |
| } |
| |
| impl<I> ParallelIterator for MaxLen<I> |
| where |
| I: IndexedParallelIterator, |
| { |
| type Item = I::Item; |
| |
| fn drive_unindexed<C>(self, consumer: C) -> C::Result |
| where |
| C: UnindexedConsumer<Self::Item>, |
| { |
| bridge(self, consumer) |
| } |
| |
| fn opt_len(&self) -> Option<usize> { |
| Some(self.len()) |
| } |
| } |
| |
| impl<I> IndexedParallelIterator for MaxLen<I> |
| where |
| I: IndexedParallelIterator, |
| { |
| fn drive<C: Consumer<Self::Item>>(self, consumer: C) -> C::Result { |
| bridge(self, consumer) |
| } |
| |
| 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, |
| max: self.max, |
| }); |
| |
| struct Callback<CB> { |
| callback: CB, |
| max: usize, |
| } |
| |
| impl<T, CB> ProducerCallback<T> for Callback<CB> |
| where |
| CB: ProducerCallback<T>, |
| { |
| type Output = CB::Output; |
| fn callback<P>(self, base: P) -> CB::Output |
| where |
| P: Producer<Item = T>, |
| { |
| let producer = MaxLenProducer { |
| base, |
| max: self.max, |
| }; |
| self.callback.callback(producer) |
| } |
| } |
| } |
| } |
| |
| /// //////////////////////////////////////////////////////////////////////// |
| /// `MaxLenProducer` implementation |
| |
| struct MaxLenProducer<P> { |
| base: P, |
| max: usize, |
| } |
| |
| impl<P> Producer for MaxLenProducer<P> |
| where |
| P: Producer, |
| { |
| type Item = P::Item; |
| type IntoIter = P::IntoIter; |
| |
| fn into_iter(self) -> Self::IntoIter { |
| self.base.into_iter() |
| } |
| |
| fn min_len(&self) -> usize { |
| self.base.min_len() |
| } |
| |
| fn max_len(&self) -> usize { |
| cmp::min(self.max, self.base.max_len()) |
| } |
| |
| fn split_at(self, index: usize) -> (Self, Self) { |
| let (left, right) = self.base.split_at(index); |
| ( |
| MaxLenProducer { |
| base: left, |
| max: self.max, |
| }, |
| MaxLenProducer { |
| base: right, |
| max: self.max, |
| }, |
| ) |
| } |
| |
| fn fold_with<F>(self, folder: F) -> F |
| where |
| F: Folder<Self::Item>, |
| { |
| self.base.fold_with(folder) |
| } |
| } |