1 | //! The `Month` enum and its associated `impl`s. |
2 | |
3 | use core::fmt; |
4 | use core::num::NonZeroU8; |
5 | use core::str::FromStr; |
6 | |
7 | use self::Month::*; |
8 | use crate::error; |
9 | |
10 | /// Months of the year. |
11 | #[allow (clippy::missing_docs_in_private_items)] // variants |
12 | #[repr (u8)] |
13 | #[derive (Debug, Clone, Copy, PartialEq, Eq, Hash)] |
14 | pub enum Month { |
15 | January = 1, |
16 | February = 2, |
17 | March = 3, |
18 | April = 4, |
19 | May = 5, |
20 | June = 6, |
21 | July = 7, |
22 | August = 8, |
23 | September = 9, |
24 | October = 10, |
25 | November = 11, |
26 | December = 12, |
27 | } |
28 | |
29 | impl Month { |
30 | /// Create a `Month` from its numerical value. |
31 | pub(crate) const fn from_number(n: NonZeroU8) -> Result<Self, error::ComponentRange> { |
32 | match n.get() { |
33 | 1 => Ok(January), |
34 | 2 => Ok(February), |
35 | 3 => Ok(March), |
36 | 4 => Ok(April), |
37 | 5 => Ok(May), |
38 | 6 => Ok(June), |
39 | 7 => Ok(July), |
40 | 8 => Ok(August), |
41 | 9 => Ok(September), |
42 | 10 => Ok(October), |
43 | 11 => Ok(November), |
44 | 12 => Ok(December), |
45 | n => Err(error::ComponentRange { |
46 | name: "month" , |
47 | minimum: 1, |
48 | maximum: 12, |
49 | value: n as _, |
50 | conditional_range: false, |
51 | }), |
52 | } |
53 | } |
54 | |
55 | /// Get the previous month. |
56 | /// |
57 | /// ```rust |
58 | /// # use time::Month; |
59 | /// assert_eq!(Month::January.previous(), Month::December); |
60 | /// ``` |
61 | pub const fn previous(self) -> Self { |
62 | match self { |
63 | January => December, |
64 | February => January, |
65 | March => February, |
66 | April => March, |
67 | May => April, |
68 | June => May, |
69 | July => June, |
70 | August => July, |
71 | September => August, |
72 | October => September, |
73 | November => October, |
74 | December => November, |
75 | } |
76 | } |
77 | |
78 | /// Get the next month. |
79 | /// |
80 | /// ```rust |
81 | /// # use time::Month; |
82 | /// assert_eq!(Month::January.next(), Month::February); |
83 | /// ``` |
84 | pub const fn next(self) -> Self { |
85 | match self { |
86 | January => February, |
87 | February => March, |
88 | March => April, |
89 | April => May, |
90 | May => June, |
91 | June => July, |
92 | July => August, |
93 | August => September, |
94 | September => October, |
95 | October => November, |
96 | November => December, |
97 | December => January, |
98 | } |
99 | } |
100 | } |
101 | |
102 | impl fmt::Display for Month { |
103 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
104 | f.write_str(data:match self { |
105 | January => "January" , |
106 | February => "February" , |
107 | March => "March" , |
108 | April => "April" , |
109 | May => "May" , |
110 | June => "June" , |
111 | July => "July" , |
112 | August => "August" , |
113 | September => "September" , |
114 | October => "October" , |
115 | November => "November" , |
116 | December => "December" , |
117 | }) |
118 | } |
119 | } |
120 | |
121 | impl FromStr for Month { |
122 | type Err = error::InvalidVariant; |
123 | |
124 | fn from_str(s: &str) -> Result<Self, Self::Err> { |
125 | match s { |
126 | "January" => Ok(January), |
127 | "February" => Ok(February), |
128 | "March" => Ok(March), |
129 | "April" => Ok(April), |
130 | "May" => Ok(May), |
131 | "June" => Ok(June), |
132 | "July" => Ok(July), |
133 | "August" => Ok(August), |
134 | "September" => Ok(September), |
135 | "October" => Ok(October), |
136 | "November" => Ok(November), |
137 | "December" => Ok(December), |
138 | _ => Err(error::InvalidVariant), |
139 | } |
140 | } |
141 | } |
142 | |
143 | impl From<Month> for u8 { |
144 | fn from(month: Month) -> Self { |
145 | month as _ |
146 | } |
147 | } |
148 | |
149 | impl TryFrom<u8> for Month { |
150 | type Error = error::ComponentRange; |
151 | |
152 | fn try_from(value: u8) -> Result<Self, Self::Error> { |
153 | match NonZeroU8::new(value) { |
154 | Some(value: NonZero) => Self::from_number(value), |
155 | None => Err(error::ComponentRange { |
156 | name: "month" , |
157 | minimum: 1, |
158 | maximum: 12, |
159 | value: 0, |
160 | conditional_range: false, |
161 | }), |
162 | } |
163 | } |
164 | } |
165 | |