async-selector 0.4.0

Fast and flexible asynchronous task selector
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134

//! [`Selector`](super::Selector) visitors.

use crate::{
    list::{Cursor, List},
    selector::{Borrowed, BorrowedMut, Removed},
};

/// Returned from [`Selector::into_iter`](super::Selector::into_iter).
pub struct IntoIter<T>(pub(super) List<T>);

impl<T> Iterator for IntoIter<T> {
    type Item = Removed<T>;

    fn next(&mut self) -> Option<Self::Item> {
        self.0.cursor_mut().remove_front().map(Removed)
    }

    fn size_hint(&self) -> (usize, Option<usize>) {
        let len = self.0.len();
        (len, Some(len))
    }
}

impl<T> ExactSizeIterator for IntoIter<T> {
    fn len(&self) -> usize {
        self.0.len()
    }
}

impl<T> DoubleEndedIterator for IntoIter<T> {
    fn next_back(&mut self) -> Option<Self::Item> {
        self.0.cursor_mut().remove_back().map(Removed)
    }
}

/// Returned from [`Selector::iter`](super::Selector::iter).
pub struct Iter<'a, T>(pub(super) Cursor<T, &'a List<T>>);

impl<'a, T> Iterator for Iter<'a, T> {
    type Item = Borrowed<'a, T>;

    fn next(&mut self) -> Option<Self::Item> {
        self.0.pop_front().map(Borrowed)
    }

    fn size_hint(&self) -> (usize, Option<usize>) {
        let len = self.len();
        (len, Some(len))
    }
}

impl<T> ExactSizeIterator for Iter<'_, T> {
    fn len(&self) -> usize {
        self.0.len()
    }
}

impl<T> DoubleEndedIterator for Iter<'_, T> {
    fn next_back(&mut self) -> Option<Self::Item> {
        self.0.pop_back().map(Borrowed)
    }
}

/// Returned from [`Selector::iter_mut`](super::Selector::iter_mut).
pub struct IterMut<'a, T>(pub(super) Cursor<T, &'a mut List<T>>);

impl<'a, T> Iterator for IterMut<'a, T> {
    type Item = BorrowedMut<'a, T>;

    fn next(&mut self) -> Option<Self::Item> {
        self.0.pop_front().map(BorrowedMut)
    }

    fn size_hint(&self) -> (usize, Option<usize>) {
        let len = self.len();
        (len, Some(len))
    }
}

impl<T> ExactSizeIterator for IterMut<'_, T> {
    fn len(&self) -> usize {
        self.0.len()
    }
}

impl<T> DoubleEndedIterator for IterMut<'_, T> {
    fn next_back(&mut self) -> Option<Self::Item> {
        self.0.pop_back().map(BorrowedMut)
    }
}

/// Returned from [`Selector::extract_if`](super::Selector::extract_if).
pub struct ExtractIf<'a, T, F> {
    pub(super) cursor: Cursor<T, &'a mut List<T>>,
    pub(super) pred: F,
}

impl<'a, T, F> Iterator for ExtractIf<'a, T, F>
where
    F: for<'b> FnMut(BorrowedMut<'b, T>) -> bool,
{
    type Item = Removed<T>;

    fn next(&mut self) -> Option<Self::Item> {
        loop {
            let next = self.cursor.peek_front()?;
            if (self.pred)(BorrowedMut(next)) {
                break self.cursor.remove_front().map(Removed);
            } else {
                self.cursor.pop_front();
            }
        }
    }

    fn size_hint(&self) -> (usize, Option<usize>) {
        (0, None)
    }
}

impl<'a, T, F> DoubleEndedIterator for ExtractIf<'a, T, F>
where
    F: for<'b> FnMut(BorrowedMut<'b, T>) -> bool,
{
    fn next_back(&mut self) -> Option<Self::Item> {
        loop {
            let back = self.cursor.peek_back()?;
            if (self.pred)(BorrowedMut(back)) {
                break self.cursor.remove_back().map(Removed);
            } else {
                self.cursor.pop_back();
            }
        }
    }
}