| use super::plumbing::*; |
| use super::*; |
| use std::cmp; |
| use std::iter; |
| |
| /// `Zip` is an iterator that zips up `a` and `b` into a single iterator |
| /// of pairs. This struct is created by the [`zip()`] method on |
| /// [`IndexedParallelIterator`] |
| /// |
| /// [`zip()`]: trait.IndexedParallelIterator.html#method.zip |
| /// [`IndexedParallelIterator`]: trait.IndexedParallelIterator.html |
| #[must_use = "iterator adaptors are lazy and do nothing unless consumed"] |
| #[derive(Debug, Clone)] |
| pub struct Zip<A: IndexedParallelIterator, B: IndexedParallelIterator> { |
| a: A, |
| b: B, |
| } |
| |
| impl<A, B> Zip<A, B> |
| where |
| A: IndexedParallelIterator, |
| B: IndexedParallelIterator, |
| { |
| /// Creates a new `Zip` iterator. |
| pub(super) fn new(a: A, b: B) -> Self { |
| Zip { a, b } |
| } |
| } |
| |
| impl<A, B> ParallelIterator for Zip<A, B> |
| where |
| A: IndexedParallelIterator, |
| B: IndexedParallelIterator, |
| { |
| type Item = (A::Item, B::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<A, B> IndexedParallelIterator for Zip<A, B> |
| where |
| A: IndexedParallelIterator, |
| B: IndexedParallelIterator, |
| { |
| fn drive<C>(self, consumer: C) -> C::Result |
| where |
| C: Consumer<Self::Item>, |
| { |
| bridge(self, consumer) |
| } |
| |
| fn len(&self) -> usize { |
| cmp::min(self.a.len(), self.b.len()) |
| } |
| |
| fn with_producer<CB>(self, callback: CB) -> CB::Output |
| where |
| CB: ProducerCallback<Self::Item>, |
| { |
| return self.a.with_producer(CallbackA { |
| callback, |
| b: self.b, |
| }); |
| |
| struct CallbackA<CB, B> { |
| callback: CB, |
| b: B, |
| } |
| |
| impl<CB, ITEM, B> ProducerCallback<ITEM> for CallbackA<CB, B> |
| where |
| B: IndexedParallelIterator, |
| CB: ProducerCallback<(ITEM, B::Item)>, |
| { |
| type Output = CB::Output; |
| |
| fn callback<A>(self, a_producer: A) -> Self::Output |
| where |
| A: Producer<Item = ITEM>, |
| { |
| self.b.with_producer(CallbackB { |
| a_producer, |
| callback: self.callback, |
| }) |
| } |
| } |
| |
| struct CallbackB<CB, A> { |
| a_producer: A, |
| callback: CB, |
| } |
| |
| impl<CB, A, ITEM> ProducerCallback<ITEM> for CallbackB<CB, A> |
| where |
| A: Producer, |
| CB: ProducerCallback<(A::Item, ITEM)>, |
| { |
| type Output = CB::Output; |
| |
| fn callback<B>(self, b_producer: B) -> Self::Output |
| where |
| B: Producer<Item = ITEM>, |
| { |
| self.callback.callback(ZipProducer { |
| a: self.a_producer, |
| b: b_producer, |
| }) |
| } |
| } |
| } |
| } |
| |
| /// //////////////////////////////////////////////////////////////////////// |
| |
| struct ZipProducer<A: Producer, B: Producer> { |
| a: A, |
| b: B, |
| } |
| |
| impl<A: Producer, B: Producer> Producer for ZipProducer<A, B> { |
| type Item = (A::Item, B::Item); |
| type IntoIter = iter::Zip<A::IntoIter, B::IntoIter>; |
| |
| fn into_iter(self) -> Self::IntoIter { |
| self.a.into_iter().zip(self.b.into_iter()) |
| } |
| |
| fn min_len(&self) -> usize { |
| cmp::max(self.a.min_len(), self.b.min_len()) |
| } |
| |
| fn max_len(&self) -> usize { |
| cmp::min(self.a.max_len(), self.b.max_len()) |
| } |
| |
| fn split_at(self, index: usize) -> (Self, Self) { |
| let (a_left, a_right) = self.a.split_at(index); |
| let (b_left, b_right) = self.b.split_at(index); |
| ( |
| ZipProducer { |
| a: a_left, |
| b: b_left, |
| }, |
| ZipProducer { |
| a: a_right, |
| b: b_right, |
| }, |
| ) |
| } |
| } |