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()`]: trait.IndexedParallelIterator.html#method.zip
10/// [`IndexedParallelIterator`]: trait.IndexedParallelIterator.html
11#[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
12#[derive(Debug, Clone)]
13pub struct Zip<A: IndexedParallelIterator, B: IndexedParallelIterator> {
14    a: A,
15    b: B,
16}
17
18impl<A, B> Zip<A, B>
19where
20    A: IndexedParallelIterator,
21    B: IndexedParallelIterator,
22{
23    /// Creates a new `Zip` iterator.
24    pub(super) fn new(a: A, b: B) -> Self {
25        Zip { a, b }
26    }
27}
28
29impl<A, B> ParallelIterator for Zip<A, B>
30where
31    A: IndexedParallelIterator,
32    B: IndexedParallelIterator,
33{
34    type Item = (A::Item, B::Item);
35
36    fn drive_unindexed<C>(self, consumer: C) -> C::Result
37    where
38        C: UnindexedConsumer<Self::Item>,
39    {
40        bridge(self, consumer)
41    }
42
43    fn opt_len(&self) -> Option<usize> {
44        Some(self.len())
45    }
46}
47
48impl<A, B> IndexedParallelIterator for Zip<A, B>
49where
50    A: IndexedParallelIterator,
51    B: IndexedParallelIterator,
52{
53    fn drive<C>(self, consumer: C) -> C::Result
54    where
55        C: Consumer<Self::Item>,
56    {
57        bridge(self, consumer)
58    }
59
60    fn len(&self) -> usize {
61        Ord::min(self.a.len(), self.b.len())
62    }
63
64    fn with_producer<CB>(self, callback: CB) -> CB::Output
65    where
66        CB: ProducerCallback<Self::Item>,
67    {
68        return self.a.with_producer(CallbackA {
69            callback,
70            b: self.b,
71        });
72
73        struct CallbackA<CB, B> {
74            callback: CB,
75            b: B,
76        }
77
78        impl<CB, ITEM, B> ProducerCallback<ITEM> for CallbackA<CB, B>
79        where
80            B: IndexedParallelIterator,
81            CB: ProducerCallback<(ITEM, B::Item)>,
82        {
83            type Output = CB::Output;
84
85            fn callback<A>(self, a_producer: A) -> Self::Output
86            where
87                A: Producer<Item = ITEM>,
88            {
89                self.b.with_producer(CallbackB {
90                    a_producer,
91                    callback: self.callback,
92                })
93            }
94        }
95
96        struct CallbackB<CB, A> {
97            a_producer: A,
98            callback: CB,
99        }
100
101        impl<CB, A, ITEM> ProducerCallback<ITEM> for CallbackB<CB, A>
102        where
103            A: Producer,
104            CB: ProducerCallback<(A::Item, ITEM)>,
105        {
106            type Output = CB::Output;
107
108            fn callback<B>(self, b_producer: B) -> Self::Output
109            where
110                B: Producer<Item = ITEM>,
111            {
112                self.callback.callback(ZipProducer {
113                    a: self.a_producer,
114                    b: b_producer,
115                })
116            }
117        }
118    }
119}
120
121/// ////////////////////////////////////////////////////////////////////////
122
123struct ZipProducer<A: Producer, B: Producer> {
124    a: A,
125    b: B,
126}
127
128impl<A: Producer, B: Producer> Producer for ZipProducer<A, B> {
129    type Item = (A::Item, B::Item);
130    type IntoIter = iter::Zip<A::IntoIter, B::IntoIter>;
131
132    fn into_iter(self) -> Self::IntoIter {
133        self.a.into_iter().zip(self.b.into_iter())
134    }
135
136    fn min_len(&self) -> usize {
137        Ord::max(self.a.min_len(), self.b.min_len())
138    }
139
140    fn max_len(&self) -> usize {
141        Ord::min(self.a.max_len(), self.b.max_len())
142    }
143
144    fn split_at(self, index: usize) -> (Self, Self) {
145        let (a_left, a_right) = self.a.split_at(index);
146        let (b_left, b_right) = self.b.split_at(index);
147        (
148            ZipProducer {
149                a: a_left,
150                b: b_left,
151            },
152            ZipProducer {
153                a: a_right,
154                b: b_right,
155            },
156        )
157    }
158}
rayon/iter/zip.rs

rayon/iter/
zip.rs
