summaryrefslogtreecommitdiff
path: root/vendor/rayon/src/iter/rev.rs
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/rayon/src/iter/rev.rs')
-rw-r--r--vendor/rayon/src/iter/rev.rs123
1 files changed, 123 insertions, 0 deletions
diff --git a/vendor/rayon/src/iter/rev.rs b/vendor/rayon/src/iter/rev.rs
new file mode 100644
index 0000000..a4c3b7c
--- /dev/null
+++ b/vendor/rayon/src/iter/rev.rs
@@ -0,0 +1,123 @@
+use super::plumbing::*;
+use super::*;
+use std::iter;
+
+/// `Rev` is an iterator that produces elements in reverse order. This struct
+/// is created by the [`rev()`] method on [`IndexedParallelIterator`]
+///
+/// [`rev()`]: trait.IndexedParallelIterator.html#method.rev
+/// [`IndexedParallelIterator`]: trait.IndexedParallelIterator.html
+#[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
+#[derive(Debug, Clone)]
+pub struct Rev<I: IndexedParallelIterator> {
+ base: I,
+}
+
+impl<I> Rev<I>
+where
+ I: IndexedParallelIterator,
+{
+ /// Creates a new `Rev` iterator.
+ pub(super) fn new(base: I) -> Self {
+ Rev { base }
+ }
+}
+
+impl<I> ParallelIterator for Rev<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 Rev<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>,
+ {
+ let len = self.base.len();
+ return self.base.with_producer(Callback { callback, len });
+
+ struct Callback<CB> {
+ callback: CB,
+ len: 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 = RevProducer {
+ base,
+ len: self.len,
+ };
+ self.callback.callback(producer)
+ }
+ }
+ }
+}
+
+struct RevProducer<P> {
+ base: P,
+ len: usize,
+}
+
+impl<P> Producer for RevProducer<P>
+where
+ P: Producer,
+{
+ type Item = P::Item;
+ type IntoIter = iter::Rev<P::IntoIter>;
+
+ fn into_iter(self) -> Self::IntoIter {
+ self.base.into_iter().rev()
+ }
+
+ 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) {
+ let (left, right) = self.base.split_at(self.len - index);
+ (
+ RevProducer {
+ base: right,
+ len: index,
+ },
+ RevProducer {
+ base: left,
+ len: self.len - index,
+ },
+ )
+ }
+}