/rust/registry/src/index.crates.io-1949cf8c6b5b557f/rayon-1.11.0/src/iter/rev.rs

Source
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()`]: IndexedParallelIterator::rev()
#[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
#[derive(Debug, Clone)]
pub struct Rev<I> {
    base: I,
}

impl<I> Rev<I> {
    /// 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,
            },
        )
    }
}

Line	Count	Source
1		use super::plumbing::*;
2		use super::*;
3		use std::iter;
4
5		/// `Rev` is an iterator that produces elements in reverse order. This struct
6		/// is created by the [`rev()`] method on [`IndexedParallelIterator`]
7		///
8		/// [`rev()`]: IndexedParallelIterator::rev()
9		#[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
10		#[derive(Debug, Clone)]
11		pub struct Rev<I> {
12		base: I,
13		}
14
15		impl<I> Rev<I> {
16		/// Creates a new `Rev` iterator.
17	0	pub(super) fn new(base: I) -> Self {
18	0	Rev { base }
19	0	}
20		}
21
22		impl<I> ParallelIterator for Rev<I>
23		where
24		I: IndexedParallelIterator,
25		{
26		type Item = I::Item;
27
28	0	fn drive_unindexed<C>(self, consumer: C) -> C::Result
29	0	where
30	0	C: UnindexedConsumer<Self::Item>,
31		{
32	0	bridge(self, consumer)
33	0	}
34
35	0	fn opt_len(&self) -> Option<usize> {
36	0	Some(self.len())
37	0	}
38		}
39
40		impl<I> IndexedParallelIterator for Rev<I>
41		where
42		I: IndexedParallelIterator,
43		{
44	0	fn drive<C: Consumer<Self::Item>>(self, consumer: C) -> C::Result {
45	0	bridge(self, consumer)
46	0	}
47
48	0	fn len(&self) -> usize {
49	0	self.base.len()
50	0	}
51
52	0	fn with_producer<CB>(self, callback: CB) -> CB::Output
53	0	where
54	0	CB: ProducerCallback<Self::Item>,
55		{
56	0	let len = self.base.len();
57	0	return self.base.with_producer(Callback { callback, len });
58
59		struct Callback<CB> {
60		callback: CB,
61		len: usize,
62		}
63
64		impl<T, CB> ProducerCallback<T> for Callback<CB>
65		where
66		CB: ProducerCallback<T>,
67		{
68		type Output = CB::Output;
69	0	fn callback<P>(self, base: P) -> CB::Output
70	0	where
71	0	P: Producer<Item = T>,
72		{
73	0	let producer = RevProducer {
74	0	base,
75	0	len: self.len,
76	0	};
77	0	self.callback.callback(producer)
78	0	}
79		}
80	0	}
81		}
82
83		struct RevProducer<P> {
84		base: P,
85		len: usize,
86		}
87
88		impl<P> Producer for RevProducer<P>
89		where
90		P: Producer,
91		{
92		type Item = P::Item;
93		type IntoIter = iter::Rev<P::IntoIter>;
94
95	0	fn into_iter(self) -> Self::IntoIter {
96	0	self.base.into_iter().rev()
97	0	}
98
99	0	fn min_len(&self) -> usize {
100	0	self.base.min_len()
101	0	}
102	0	fn max_len(&self) -> usize {
103	0	self.base.max_len()
104	0	}
105
106	0	fn split_at(self, index: usize) -> (Self, Self) {
107	0	let (left, right) = self.base.split_at(self.len - index);
108	0	(
109	0	RevProducer {
110	0	base: right,
111	0	len: index,
112	0	},
113	0	RevProducer {
114	0	base: left,
115	0	len: self.len - index,
116	0	},
117	0	)
118	0	}
119		}

Coverage Report

Created: 2025-10-14 06:57