time/iter/
weekday_iter.rs

1//! An infinite iterator over [`Weekday`]s.
2
3use core::iter::FusedIterator;
4
5use super::Rev;
6use crate::Weekday::{self, *};
7
8const ALL_WEEKDAYS: [Weekday; 7] = [
9    Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday,
10];
11
12/// An infinite iterator over [`Weekday`]s.
13///
14/// This struct is created by [`Weekday::iter_from`] or [`WeekdayIter::new`].
15#[derive(Debug, Clone, PartialEq, Eq)]
16pub struct WeekdayIter {
17    current: Weekday,
18}
19
20impl WeekdayIter {
21    /// Create a new `WeekdayIter` starting at `start`.
22    ///
23    /// ```rust
24    /// # use time::{Weekday, iter::WeekdayIter};
25    /// let mut iter = WeekdayIter::new(Weekday::Monday);
26    /// assert_eq!(iter.next(), Some(Weekday::Monday));
27    /// assert_eq!(iter.next(), Some(Weekday::Tuesday));
28    /// assert_eq!(iter.next(), Some(Weekday::Wednesday));
29    /// ```
30    #[inline]
31    pub const fn new(start: Weekday) -> Self {
32        Self { current: start }
33    }
34
35    /// Make the iterator go in reverse order.
36    ///
37    /// ```rust
38    /// # use time::{Weekday, iter::WeekdayIter};
39    /// let mut iter = WeekdayIter::new(Weekday::Monday).rev();
40    /// assert_eq!(iter.next(), Some(Weekday::Monday));
41    /// assert_eq!(iter.next(), Some(Weekday::Sunday));
42    /// assert_eq!(iter.next(), Some(Weekday::Saturday));
43    /// ```
44    #[inline]
45    pub const fn rev(self) -> Rev<Self> {
46        Rev { iter: self }
47    }
48}
49
50impl Iterator for WeekdayIter {
51    type Item = Weekday;
52
53    #[inline]
54    fn next(&mut self) -> Option<Self::Item> {
55        let current = self.current;
56        self.current = current.next();
57        Some(current)
58    }
59
60    #[inline]
61    fn size_hint(&self) -> (usize, Option<usize>) {
62        (usize::MAX, None)
63    }
64
65    #[inline]
66    fn nth(&mut self, n: usize) -> Option<Self::Item> {
67        let result = self.current.nth_next((n % 7) as u8);
68        self.current = result.next();
69        Some(result)
70    }
71
72    fn count(self) -> usize {
73        panic!("`WeekdayIter` is infinite and cannot be counted")
74    }
75
76    fn last(self) -> Option<Self::Item> {
77        panic!("`WeekdayIter` is infinite and has no last element")
78    }
79
80    #[inline]
81    fn all<F>(&mut self, f: F) -> bool
82    where
83        F: FnMut(Self::Item) -> bool,
84    {
85        ALL_WEEKDAYS.into_iter().all(f)
86    }
87
88    #[inline]
89    fn any<F>(&mut self, f: F) -> bool
90    where
91        F: FnMut(Self::Item) -> bool,
92    {
93        ALL_WEEKDAYS.into_iter().any(f)
94    }
95}
96
97impl Iterator for Rev<WeekdayIter> {
98    type Item = Weekday;
99
100    #[inline]
101    fn next(&mut self) -> Option<Self::Item> {
102        let current = self.iter.current;
103        self.iter.current = current.previous();
104        Some(current)
105    }
106
107    #[inline]
108    fn size_hint(&self) -> (usize, Option<usize>) {
109        (usize::MAX, None)
110    }
111
112    #[inline]
113    fn nth(&mut self, n: usize) -> Option<Self::Item> {
114        let result = self.iter.current.nth_prev((n % 7) as u8);
115        self.iter.current = result.previous();
116        Some(result)
117    }
118
119    fn count(self) -> usize {
120        panic!("`Rev<WeekdayIter>` is infinite and cannot be counted")
121    }
122
123    fn last(self) -> Option<Self::Item> {
124        panic!("`Rev<WeekdayIter>` is infinite and has no last element")
125    }
126
127    #[inline]
128    fn all<F>(&mut self, f: F) -> bool
129    where
130        F: FnMut(Self::Item) -> bool,
131    {
132        ALL_WEEKDAYS.into_iter().all(f)
133    }
134
135    #[inline]
136    fn any<F>(&mut self, f: F) -> bool
137    where
138        F: FnMut(Self::Item) -> bool,
139    {
140        ALL_WEEKDAYS.into_iter().any(f)
141    }
142}
143
144impl FusedIterator for WeekdayIter {}
145impl FusedIterator for Rev<WeekdayIter> {}
time/iter/weekday_iter.rs

time/iter/
weekday_iter.rs
