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Diffstat (limited to 'vendor/rayon/src/iter/zip.rs')
-rw-r--r-- | vendor/rayon/src/iter/zip.rs | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/vendor/rayon/src/iter/zip.rs b/vendor/rayon/src/iter/zip.rs new file mode 100644 index 0000000..33823db --- /dev/null +++ b/vendor/rayon/src/iter/zip.rs @@ -0,0 +1,159 @@ +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, + }, + ) + } +} |