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//! Days of the week.
use core::fmt::{self, Display};
use core::str::FromStr;
use Weekday::*;
use crate::error;
/// Days of the week.
///
/// As order is dependent on context (Sunday could be either two days after or five days before
/// Friday), this type does not implement `PartialOrd` or `Ord`.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub enum Weekday {
#[allow(clippy::missing_docs_in_private_items)]
Monday,
#[allow(clippy::missing_docs_in_private_items)]
Tuesday,
#[allow(clippy::missing_docs_in_private_items)]
Wednesday,
#[allow(clippy::missing_docs_in_private_items)]
Thursday,
#[allow(clippy::missing_docs_in_private_items)]
Friday,
#[allow(clippy::missing_docs_in_private_items)]
Saturday,
#[allow(clippy::missing_docs_in_private_items)]
Sunday,
}
impl Weekday {
/// Get the previous weekday.
///
/// ```rust
/// # use time::Weekday;
/// assert_eq!(Weekday::Tuesday.previous(), Weekday::Monday);
/// ```
pub const fn previous(self) -> Self {
match self {
Monday => Sunday,
Tuesday => Monday,
Wednesday => Tuesday,
Thursday => Wednesday,
Friday => Thursday,
Saturday => Friday,
Sunday => Saturday,
}
}
/// Get the next weekday.
///
/// ```rust
/// # use time::Weekday;
/// assert_eq!(Weekday::Monday.next(), Weekday::Tuesday);
/// ```
pub const fn next(self) -> Self {
match self {
Monday => Tuesday,
Tuesday => Wednesday,
Wednesday => Thursday,
Thursday => Friday,
Friday => Saturday,
Saturday => Sunday,
Sunday => Monday,
}
}
/// Get n-th next day.
///
/// ```rust
/// # use time::Weekday;
/// assert_eq!(Weekday::Monday.nth_next(1), Weekday::Tuesday);
/// assert_eq!(Weekday::Sunday.nth_next(10), Weekday::Wednesday);
/// ```
pub const fn nth_next(self, n: u8) -> Self {
match (self.number_days_from_monday() + n % 7) % 7 {
0 => Monday,
1 => Tuesday,
2 => Wednesday,
3 => Thursday,
4 => Friday,
5 => Saturday,
val => {
debug_assert!(val == 6);
Sunday
}
}
}
/// Get n-th previous day.
///
/// ```rust
/// # use time::Weekday;
/// assert_eq!(Weekday::Monday.nth_prev(1), Weekday::Sunday);
/// assert_eq!(Weekday::Sunday.nth_prev(10), Weekday::Thursday);
/// ```
pub const fn nth_prev(self, n: u8) -> Self {
match self.number_days_from_monday() as i8 - (n % 7) as i8 {
1 | -6 => Tuesday,
2 | -5 => Wednesday,
3 | -4 => Thursday,
4 | -3 => Friday,
5 | -2 => Saturday,
6 | -1 => Sunday,
val => {
debug_assert!(val == 0);
Monday
}
}
}
/// Get the one-indexed number of days from Monday.
///
/// ```rust
/// # use time::Weekday;
/// assert_eq!(Weekday::Monday.number_from_monday(), 1);
/// ```
#[doc(alias = "iso_weekday_number")]
pub const fn number_from_monday(self) -> u8 {
self.number_days_from_monday() + 1
}
/// Get the one-indexed number of days from Sunday.
///
/// ```rust
/// # use time::Weekday;
/// assert_eq!(Weekday::Monday.number_from_sunday(), 2);
/// ```
pub const fn number_from_sunday(self) -> u8 {
self.number_days_from_sunday() + 1
}
/// Get the zero-indexed number of days from Monday.
///
/// ```rust
/// # use time::Weekday;
/// assert_eq!(Weekday::Monday.number_days_from_monday(), 0);
/// ```
pub const fn number_days_from_monday(self) -> u8 {
self as _
}
/// Get the zero-indexed number of days from Sunday.
///
/// ```rust
/// # use time::Weekday;
/// assert_eq!(Weekday::Monday.number_days_from_sunday(), 1);
/// ```
pub const fn number_days_from_sunday(self) -> u8 {
match self {
Monday => 1,
Tuesday => 2,
Wednesday => 3,
Thursday => 4,
Friday => 5,
Saturday => 6,
Sunday => 0,
}
}
}
impl Display for Weekday {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.write_str(match self {
Monday => "Monday",
Tuesday => "Tuesday",
Wednesday => "Wednesday",
Thursday => "Thursday",
Friday => "Friday",
Saturday => "Saturday",
Sunday => "Sunday",
})
}
}
impl FromStr for Weekday {
type Err = error::InvalidVariant;
fn from_str(s: &str) -> Result<Self, Self::Err> {
match s {
"Monday" => Ok(Monday),
"Tuesday" => Ok(Tuesday),
"Wednesday" => Ok(Wednesday),
"Thursday" => Ok(Thursday),
"Friday" => Ok(Friday),
"Saturday" => Ok(Saturday),
"Sunday" => Ok(Sunday),
_ => Err(error::InvalidVariant),
}
}
}