rayon/iter/
zip.rs

1use super::plumbing::*;
2use super::*;
3use std::iter;
4
5/// `Zip` is an iterator that zips up `a` and `b` into a single iterator
6/// of pairs. This struct is created by the [`zip()`] method on
7/// [`IndexedParallelIterator`]
8///
9/// [`zip()`]: IndexedParallelIterator::zip()
10#[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
11#[derive(Debug, Clone)]
12pub struct Zip<A, B> {
13    a: A,
14    b: B,
15}
16
17impl<A, B> Zip<A, B> {
18    /// Creates a new `Zip` iterator.
19    pub(super) fn new(a: A, b: B) -> Self {
20        Zip { a, b }
21    }
22}
23
24impl<A, B> ParallelIterator for Zip<A, B>
25where
26    A: IndexedParallelIterator,
27    B: IndexedParallelIterator,
28{
29    type Item = (A::Item, B::Item);
30
31    fn drive_unindexed<C>(self, consumer: C) -> C::Result
32    where
33        C: UnindexedConsumer<Self::Item>,
34    {
35        bridge(self, consumer)
36    }
37
38    fn opt_len(&self) -> Option<usize> {
39        Some(self.len())
40    }
41}
42
43impl<A, B> IndexedParallelIterator for Zip<A, B>
44where
45    A: IndexedParallelIterator,
46    B: IndexedParallelIterator,
47{
48    fn drive<C>(self, consumer: C) -> C::Result
49    where
50        C: Consumer<Self::Item>,
51    {
52        bridge(self, consumer)
53    }
54
55    fn len(&self) -> usize {
56        Ord::min(self.a.len(), self.b.len())
57    }
58
59    fn with_producer<CB>(self, callback: CB) -> CB::Output
60    where
61        CB: ProducerCallback<Self::Item>,
62    {
63        return self.a.with_producer(CallbackA {
64            callback,
65            b: self.b,
66        });
67
68        struct CallbackA<CB, B> {
69            callback: CB,
70            b: B,
71        }
72
73        impl<CB, ITEM, B> ProducerCallback<ITEM> for CallbackA<CB, B>
74        where
75            B: IndexedParallelIterator,
76            CB: ProducerCallback<(ITEM, B::Item)>,
77        {
78            type Output = CB::Output;
79
80            fn callback<A>(self, a_producer: A) -> Self::Output
81            where
82                A: Producer<Item = ITEM>,
83            {
84                self.b.with_producer(CallbackB {
85                    a_producer,
86                    callback: self.callback,
87                })
88            }
89        }
90
91        struct CallbackB<CB, A> {
92            a_producer: A,
93            callback: CB,
94        }
95
96        impl<CB, A, ITEM> ProducerCallback<ITEM> for CallbackB<CB, A>
97        where
98            A: Producer,
99            CB: ProducerCallback<(A::Item, ITEM)>,
100        {
101            type Output = CB::Output;
102
103            fn callback<B>(self, b_producer: B) -> Self::Output
104            where
105                B: Producer<Item = ITEM>,
106            {
107                self.callback.callback(ZipProducer {
108                    a: self.a_producer,
109                    b: b_producer,
110                })
111            }
112        }
113    }
114}
115
116// ////////////////////////////////////////////////////////////////////////
117
118struct ZipProducer<A: Producer, B: Producer> {
119    a: A,
120    b: B,
121}
122
123impl<A: Producer, B: Producer> Producer for ZipProducer<A, B> {
124    type Item = (A::Item, B::Item);
125    type IntoIter = iter::Zip<A::IntoIter, B::IntoIter>;
126
127    fn into_iter(self) -> Self::IntoIter {
128        self.a.into_iter().zip(self.b.into_iter())
129    }
130
131    fn min_len(&self) -> usize {
132        Ord::max(self.a.min_len(), self.b.min_len())
133    }
134
135    fn max_len(&self) -> usize {
136        Ord::min(self.a.max_len(), self.b.max_len())
137    }
138
139    fn split_at(self, index: usize) -> (Self, Self) {
140        let (a_left, a_right) = self.a.split_at(index);
141        let (b_left, b_right) = self.b.split_at(index);
142        (
143            ZipProducer {
144                a: a_left,
145                b: b_left,
146            },
147            ZipProducer {
148                a: a_right,
149                b: b_right,
150            },
151        )
152    }
153}
rayon/iter/zip.rs

rayon/iter/
zip.rs
