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// This file is part of ICU4X. For terms of use, please see the file
// called LICENSE at the top level of the ICU4X source tree
//! This module contains types and implementations for the Coptic calendar.
//!
//! ```rust
//! use icu::calendar::{cal::Coptic, Date};
//!
//! let date_iso = Date::try_new_iso(1970, 1, 2)
//! .expect("Failed to initialize ISO Date instance.");
//! let date_coptic = Date::new_from_iso(date_iso, Coptic);
//!
//! assert_eq!(date_coptic.era_year().year, 1686);
//! assert_eq!(date_coptic.month().ordinal, 4);
//! assert_eq!(date_coptic.day_of_month().0, 24);
//! ```
use crate::cal::iso::{Iso, IsoDateInner};
use crate::calendar_arithmetic::{ArithmeticDate, CalendarArithmetic};
use crate::error::DateError;
use crate::{types, Calendar, Date, DateDuration, DateDurationUnit, RangeError};
use calendrical_calculations::helpers::I32CastError;
use calendrical_calculations::rata_die::RataDie;
use tinystr::tinystr;
/// The [Coptic Calendar]
///
/// The [Coptic calendar] is a solar calendar used by the Coptic Orthodox Church, with twelve normal months
/// and a thirteenth small epagomenal month.
///
/// This type can be used with [`Date`] to represent dates in this calendar.
///
///
/// # Era codes
///
/// This calendar uses a single code: `am`, corresponding to the After Diocletian/Anno Martyrum
/// era. 1 A.M. is equivalent to 284 C.E.
///
/// # Month codes
///
/// This calendar supports 13 solar month codes (`"M01" - "M13"`), with `"M13"` being used for the short epagomenal month
/// at the end of the year.
#[derive(Copy, Clone, Debug, Hash, Default, Eq, PartialEq, PartialOrd, Ord)]
#[allow(clippy::exhaustive_structs)] // this type is stable
pub struct Coptic;
/// The inner date type used for representing [`Date`]s of [`Coptic`]. See [`Date`] and [`Coptic`] for more details.
#[derive(Copy, Clone, Debug, Hash, Eq, PartialEq, PartialOrd, Ord)]
pub struct CopticDateInner(pub(crate) ArithmeticDate<Coptic>);
impl CalendarArithmetic for Coptic {
type YearInfo = i32;
fn days_in_provided_month(year: i32, month: u8) -> u8 {
if (1..=12).contains(&month) {
30
} else if month == 13 {
if Self::provided_year_is_leap(year) {
6
} else {
5
}
} else {
0
}
}
fn months_in_provided_year(_: i32) -> u8 {
13
}
fn provided_year_is_leap(year: i32) -> bool {
year.rem_euclid(4) == 3
}
fn last_month_day_in_provided_year(year: i32) -> (u8, u8) {
if Self::provided_year_is_leap(year) {
(13, 6)
} else {
(13, 5)
}
}
fn days_in_provided_year(year: i32) -> u16 {
if Self::provided_year_is_leap(year) {
366
} else {
365
}
}
}
impl crate::cal::scaffold::UnstableSealed for Coptic {}
impl Calendar for Coptic {
type DateInner = CopticDateInner;
type Year = types::EraYear;
fn from_codes(
&self,
era: Option<&str>,
year: i32,
month_code: types::MonthCode,
day: u8,
) -> Result<Self::DateInner, DateError> {
let year = match era {
Some("am") | None => year,
Some(_) => return Err(DateError::UnknownEra),
};
ArithmeticDate::new_from_codes(self, year, month_code, day).map(CopticDateInner)
}
fn from_rata_die(&self, rd: RataDie) -> Self::DateInner {
CopticDateInner(
match calendrical_calculations::coptic::coptic_from_fixed(rd) {
Err(I32CastError::BelowMin) => ArithmeticDate::min_date(),
Err(I32CastError::AboveMax) => ArithmeticDate::max_date(),
Ok((year, month, day)) => ArithmeticDate::new_unchecked(year, month, day),
},
)
}
fn to_rata_die(&self, date: &Self::DateInner) -> RataDie {
calendrical_calculations::coptic::fixed_from_coptic(date.0.year, date.0.month, date.0.day)
}
fn from_iso(&self, iso: IsoDateInner) -> CopticDateInner {
self.from_rata_die(Iso.to_rata_die(&iso))
}
fn to_iso(&self, date: &Self::DateInner) -> IsoDateInner {
Iso.from_rata_die(self.to_rata_die(date))
}
fn months_in_year(&self, date: &Self::DateInner) -> u8 {
date.0.months_in_year()
}
fn days_in_year(&self, date: &Self::DateInner) -> u16 {
date.0.days_in_year()
}
fn days_in_month(&self, date: &Self::DateInner) -> u8 {
date.0.days_in_month()
}
fn offset_date(&self, date: &mut Self::DateInner, offset: DateDuration<Self>) {
date.0.offset_date(offset, &());
}
#[allow(clippy::field_reassign_with_default)]
fn until(
&self,
date1: &Self::DateInner,
date2: &Self::DateInner,
_calendar2: &Self,
_largest_unit: DateDurationUnit,
_smallest_unit: DateDurationUnit,
) -> DateDuration<Self> {
date1.0.until(date2.0, _largest_unit, _smallest_unit)
}
fn year_info(&self, date: &Self::DateInner) -> Self::Year {
let year = self.extended_year(date);
types::EraYear {
era: tinystr!(16, "am"),
era_index: Some(0),
year,
ambiguity: types::YearAmbiguity::CenturyRequired,
}
}
fn extended_year(&self, date: &Self::DateInner) -> i32 {
date.0.extended_year()
}
fn is_in_leap_year(&self, date: &Self::DateInner) -> bool {
Self::provided_year_is_leap(date.0.year)
}
fn month(&self, date: &Self::DateInner) -> types::MonthInfo {
date.0.month()
}
fn day_of_month(&self, date: &Self::DateInner) -> types::DayOfMonth {
date.0.day_of_month()
}
fn day_of_year(&self, date: &Self::DateInner) -> types::DayOfYear {
date.0.day_of_year()
}
fn debug_name(&self) -> &'static str {
"Coptic"
}
fn calendar_algorithm(&self) -> Option<crate::preferences::CalendarAlgorithm> {
Some(crate::preferences::CalendarAlgorithm::Coptic)
}
}
impl Date<Coptic> {
/// Construct new Coptic Date.
///
/// ```rust
/// use icu::calendar::Date;
///
/// let date_coptic = Date::try_new_coptic(1686, 5, 6)
/// .expect("Failed to initialize Coptic Date instance.");
///
/// assert_eq!(date_coptic.era_year().year, 1686);
/// assert_eq!(date_coptic.month().ordinal, 5);
/// assert_eq!(date_coptic.day_of_month().0, 6);
/// ```
pub fn try_new_coptic(year: i32, month: u8, day: u8) -> Result<Date<Coptic>, RangeError> {
ArithmeticDate::new_from_ordinals(year, month, day)
.map(CopticDateInner)
.map(|inner| Date::from_raw(inner, Coptic))
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_coptic_regression() {
let iso_date = Date::try_new_iso(-100, 3, 3).unwrap();
let coptic = iso_date.to_calendar(Coptic);
let recovered_iso = coptic.to_iso();
assert_eq!(iso_date, recovered_iso);
}
}