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Diffstat (limited to 'vendor/rayon/src/iter/interleave_shortest.rs')
-rw-r--r-- | vendor/rayon/src/iter/interleave_shortest.rs | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/vendor/rayon/src/iter/interleave_shortest.rs b/vendor/rayon/src/iter/interleave_shortest.rs new file mode 100644 index 0000000..7d81369 --- /dev/null +++ b/vendor/rayon/src/iter/interleave_shortest.rs @@ -0,0 +1,85 @@ +use super::plumbing::*; +use super::*; + +/// `InterleaveShortest` is an iterator that works similarly to +/// `Interleave`, but this version stops returning elements once one +/// of the iterators run out. +/// +/// This struct is created by the [`interleave_shortest()`] method on +/// [`IndexedParallelIterator`]. +/// +/// [`interleave_shortest()`]: trait.IndexedParallelIterator.html#method.interleave_shortest +/// [`IndexedParallelIterator`]: trait.IndexedParallelIterator.html +#[must_use = "iterator adaptors are lazy and do nothing unless consumed"] +#[derive(Debug, Clone)] +pub struct InterleaveShortest<I, J> +where + I: IndexedParallelIterator, + J: IndexedParallelIterator<Item = I::Item>, +{ + interleave: Interleave<Take<I>, Take<J>>, +} + +impl<I, J> InterleaveShortest<I, J> +where + I: IndexedParallelIterator, + J: IndexedParallelIterator<Item = I::Item>, +{ + /// Creates a new `InterleaveShortest` iterator + pub(super) fn new(i: I, j: J) -> Self { + InterleaveShortest { + interleave: if i.len() <= j.len() { + // take equal lengths from both iterators + let n = i.len(); + i.take(n).interleave(j.take(n)) + } else { + // take one extra item from the first iterator + let n = j.len(); + i.take(n + 1).interleave(j.take(n)) + }, + } + } +} + +impl<I, J> ParallelIterator for InterleaveShortest<I, J> +where + I: IndexedParallelIterator, + J: IndexedParallelIterator<Item = I::Item>, +{ + type Item = I::Item; + + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: Consumer<I::Item>, + { + bridge(self, consumer) + } + + fn opt_len(&self) -> Option<usize> { + Some(self.len()) + } +} + +impl<I, J> IndexedParallelIterator for InterleaveShortest<I, J> +where + I: IndexedParallelIterator, + J: IndexedParallelIterator<Item = I::Item>, +{ + fn drive<C>(self, consumer: C) -> C::Result + where + C: Consumer<Self::Item>, + { + bridge(self, consumer) + } + + fn len(&self) -> usize { + self.interleave.len() + } + + fn with_producer<CB>(self, callback: CB) -> CB::Output + where + CB: ProducerCallback<Self::Item>, + { + self.interleave.with_producer(callback) + } +} |