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Remove CalendarArithmetic trait #7088

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6a8dd11
nuke calendar arithmetic
robertbastian Oct 14, 2025
28c53ff
improve day_of_year code
robertbastian Oct 14, 2025
2587943
Merge remote-tracking branch 'upstream/main' into arithmetic
robertbastian Oct 16, 2025
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65 changes: 23 additions & 42 deletions components/calendar/src/cal/abstract_gregorian.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3,9 +3,7 @@
// (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).

use crate::cal::iso::{IsoDateInner, IsoEra};
use crate::calendar_arithmetic::{
ArithmeticDate, ArithmeticDateBuilder, CalendarArithmetic, DateFieldsResolver,
};
use crate::calendar_arithmetic::{ArithmeticDate, ArithmeticDateBuilder, DateFieldsResolver};
use crate::error::{DateError, DateFromFieldsError, EcmaReferenceYearError, UnknownEraError};
use crate::options::DateFromFieldsOptions;
use crate::options::{DateAddOptions, DateDifferenceOptions};
Expand Down Expand Up @@ -43,7 +41,15 @@ impl ArithmeticDate<AbstractGregorian<IsoEra>> {
}
}

impl CalendarArithmetic for AbstractGregorian<IsoEra> {
pub(crate) const REFERENCE_YEAR: i32 = 1972;
#[cfg(test)]
pub(crate) const LAST_DAY_OF_REFERENCE_YEAR: RataDie =
calendrical_calculations::gregorian::day_before_year(REFERENCE_YEAR + 1);

impl<Y: GregorianYears> DateFieldsResolver for AbstractGregorian<Y> {
// Gregorian year
type YearInfo = i32;

fn days_in_provided_month(year: i32, month: u8) -> u8 {
// https://www.youtube.com/watch?v=J9KijLyP-yg&t=1394s
if month == 2 {
Expand All @@ -57,36 +63,6 @@ impl CalendarArithmetic for AbstractGregorian<IsoEra> {
12
}

fn provided_year_is_leap(year: i32) -> bool {
calendrical_calculations::gregorian::is_leap_year(year)
}

fn last_month_day_in_provided_year(_year: i32) -> (u8, u8) {
(12, 31)
}

fn days_in_provided_year(year: i32) -> u16 {
365 + calendrical_calculations::gregorian::is_leap_year(year) as u16
}

fn day_of_provided_year(year: Self::YearInfo, month: u8, day: u8) -> u16 {
calendrical_calculations::gregorian::days_before_month(year, month) + day as u16
}

fn date_from_provided_year_day(year: Self::YearInfo, year_day: u16) -> (u8, u8) {
calendrical_calculations::gregorian::year_day(year, year_day)
}
}

pub(crate) const REFERENCE_YEAR: i32 = 1972;
#[cfg(test)]
pub(crate) const LAST_DAY_OF_REFERENCE_YEAR: RataDie =
calendrical_calculations::gregorian::day_before_year(REFERENCE_YEAR + 1);

impl<Y: GregorianYears> DateFieldsResolver for AbstractGregorian<Y> {
// Gregorian year
type YearInfo = i32;

#[inline]
fn year_info_from_era(
&self,
Expand Down Expand Up @@ -130,8 +106,10 @@ impl<Y: GregorianYears> Calendar for AbstractGregorian<Y> {

fn from_rata_die(&self, date: RataDie) -> Self::DateInner {
let iso = match calendrical_calculations::gregorian::gregorian_from_fixed(date) {
Err(I32CastError::BelowMin) => ArithmeticDate::<AbstractGregorian<IsoEra>>::min_date(),
Err(I32CastError::AboveMax) => ArithmeticDate::max_date(),
Err(I32CastError::BelowMin) => {
ArithmeticDate::<AbstractGregorian<IsoEra>>::new_unchecked(i32::MIN, 1, 1)
}
Err(I32CastError::AboveMax) => ArithmeticDate::new_unchecked(i32::MAX, 12, 31),
Ok((year, month, day)) => ArithmeticDate::new_unchecked(year, month, day),
};

Expand Down Expand Up @@ -159,15 +137,15 @@ impl<Y: GregorianYears> Calendar for AbstractGregorian<Y> {
}

fn months_in_year(&self, date: &Self::DateInner) -> u8 {
date.months_in_year()
AbstractGregorian::<IsoEra>::months_in_provided_year(date.year)
}

fn days_in_year(&self, date: &Self::DateInner) -> u16 {
date.days_in_year()
365 + calendrical_calculations::gregorian::is_leap_year(date.year) as u16
}

fn days_in_month(&self, date: &Self::DateInner) -> u8 {
date.days_in_month()
AbstractGregorian::<IsoEra>::days_in_provided_month(date.year, date.month)
}

fn add(
Expand All @@ -194,19 +172,22 @@ impl<Y: GregorianYears> Calendar for AbstractGregorian<Y> {
}

fn is_in_leap_year(&self, date: &Self::DateInner) -> bool {
AbstractGregorian::<IsoEra>::provided_year_is_leap(date.year)
calendrical_calculations::gregorian::is_leap_year(date.year)
}

fn month(&self, date: &Self::DateInner) -> types::MonthInfo {
self.month_code_from_ordinal(&date.year, date.month)
}

fn day_of_month(&self, date: &Self::DateInner) -> types::DayOfMonth {
date.day_of_month()
types::DayOfMonth(date.day)
}

fn day_of_year(&self, date: &Self::DateInner) -> types::DayOfYear {
date.day_of_year()
types::DayOfYear(
calendrical_calculations::gregorian::days_before_month(date.year, date.month)
+ date.day as u16,
)
}

fn debug_name(&self) -> &'static str {
Expand Down
53 changes: 13 additions & 40 deletions components/calendar/src/cal/chinese.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4,9 +4,7 @@

use crate::cal::iso::{Iso, IsoDateInner};
use crate::calendar_arithmetic::DateFieldsResolver;
use crate::calendar_arithmetic::{
ArithmeticDate, ArithmeticDateBuilder, CalendarArithmetic, ToExtendedYear,
};
use crate::calendar_arithmetic::{ArithmeticDate, ArithmeticDateBuilder, ToExtendedYear};
use crate::error::{
DateError, DateFromFieldsError, EcmaReferenceYearError, MonthCodeError, UnknownEraError,
};
Expand Down Expand Up @@ -524,7 +522,9 @@ impl LunarChinese<China> {
}
}

impl<R: Rules> CalendarArithmetic for LunarChinese<R> {
impl<R: Rules> DateFieldsResolver for LunarChinese<R> {
type YearInfo = LunarChineseYearData;

fn days_in_provided_month(year: LunarChineseYearData, month: u8) -> u8 {
year.days_in_month(month)
}
Expand All @@ -534,31 +534,6 @@ impl<R: Rules> CalendarArithmetic for LunarChinese<R> {
year.months_in_year()
}

/// Returns true if the given year is a leap year, and false if not.
fn provided_year_is_leap(year: LunarChineseYearData) -> bool {
year.leap_month().is_some()
}

/// Returns the (month, day) of the last day in a Chinese year (the day before Chinese New Year).
/// The last month in a year will always be 12 in a common year or 13 in a leap year. The day is
/// determined by finding the day immediately before the next new year and calculating the number
/// of days since the last new moon (beginning of the last month in the year).
fn last_month_day_in_provided_year(year: LunarChineseYearData) -> (u8, u8) {
if year.leap_month().is_some() {
(13, year.days_in_month(13))
} else {
(12, year.days_in_month(12))
}
}

fn days_in_provided_year(year: LunarChineseYearData) -> u16 {
year.days_in_year()
}
}

impl<R: Rules> DateFieldsResolver for LunarChinese<R> {
type YearInfo = LunarChineseYearData;

#[inline]
fn year_info_from_era(
&self,
Expand Down Expand Up @@ -632,13 +607,12 @@ impl<R: Rules> Calendar for LunarChinese<R> {
fn from_rata_die(&self, rd: RataDie) -> Self::DateInner {
let iso = Iso.from_rata_die(rd);
let y = {
let actual_iso = iso.0.extended_year();
let candidate = self.0.year_data(actual_iso);
let candidate = self.0.year_data(iso.0.year);

if rd >= candidate.new_year() {
candidate
} else {
self.0.year_data(actual_iso - 1)
self.0.year_data(iso.0.year - 1)
}
};
let (m, d) = y.md_from_rd(rd);
Expand All @@ -652,13 +626,12 @@ impl<R: Rules> Calendar for LunarChinese<R> {
fn from_iso(&self, iso: IsoDateInner) -> Self::DateInner {
let rd = Iso.to_rata_die(&iso);
let y = {
let actual_iso = iso.0.extended_year();
let candidate = self.0.year_data(actual_iso);
let candidate = self.0.year_data(iso.0.year);

if rd >= candidate.new_year() {
candidate
} else {
self.0.year_data(actual_iso - 1)
self.0.year_data(iso.0.year - 1)
}
};
let (m, d) = y.md_from_rd(rd);
Expand All @@ -672,11 +645,11 @@ impl<R: Rules> Calendar for LunarChinese<R> {
// Count the number of months in a given year, specified by providing a date
// from that year
fn days_in_year(&self, date: &Self::DateInner) -> u16 {
date.0.days_in_year()
date.0.year.days_in_year()
}

fn days_in_month(&self, date: &Self::DateInner) -> u8 {
date.0.days_in_month()
Self::days_in_provided_month(date.0.year, date.0.month)
}

fn add(
Expand Down Expand Up @@ -711,7 +684,7 @@ impl<R: Rules> Calendar for LunarChinese<R> {
}

fn is_in_leap_year(&self, date: &Self::DateInner) -> bool {
Self::provided_year_is_leap(date.0.year)
date.0.year.leap_month().is_some()
}

/// The calendar-specific month code represented by `date`;
Expand All @@ -724,7 +697,7 @@ impl<R: Rules> Calendar for LunarChinese<R> {

/// The calendar-specific day-of-month represented by `date`
fn day_of_month(&self, date: &Self::DateInner) -> types::DayOfMonth {
date.0.day_of_month()
types::DayOfMonth(date.0.day)
}

/// Information of the day of the year
Expand All @@ -737,7 +710,7 @@ impl<R: Rules> Calendar for LunarChinese<R> {
}

fn months_in_year(&self, date: &Self::DateInner) -> u8 {
date.0.months_in_year()
Self::months_in_provided_year(date.0.year)
}
}

Expand Down
55 changes: 18 additions & 37 deletions components/calendar/src/cal/coptic.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3,7 +3,7 @@
// (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).

use crate::cal::iso::{Iso, IsoDateInner};
use crate::calendar_arithmetic::{ArithmeticDate, CalendarArithmetic};
use crate::calendar_arithmetic::ArithmeticDate;
use crate::calendar_arithmetic::{ArithmeticDateBuilder, DateFieldsResolver};
use crate::error::{
DateError, DateFromFieldsError, EcmaReferenceYearError, MonthCodeError, UnknownEraError,
Expand Down Expand Up @@ -43,12 +43,14 @@ pub struct Coptic;
#[derive(Copy, Clone, Debug, Hash, Eq, PartialEq, PartialOrd, Ord)]
pub struct CopticDateInner(pub(crate) ArithmeticDate<Coptic>);

impl CalendarArithmetic for Coptic {
impl DateFieldsResolver 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) {
if year.rem_euclid(4) == 3 {
6
} else {
5
Expand All @@ -61,31 +63,6 @@ impl CalendarArithmetic for Coptic {
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 DateFieldsResolver for Coptic {
type YearInfo = i32;

#[inline]
fn year_info_from_era(
&self,
Expand Down Expand Up @@ -166,8 +143,8 @@ impl Calendar for Coptic {
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(),
Err(I32CastError::BelowMin) => ArithmeticDate::new_unchecked(i32::MIN, 1, 1),
Err(I32CastError::AboveMax) => ArithmeticDate::new_unchecked(i32::MAX, 13, 6),
Ok((year, month, day)) => ArithmeticDate::new_unchecked(year, month, day),
},
)
Expand All @@ -186,15 +163,19 @@ impl Calendar for Coptic {
}

fn months_in_year(&self, date: &Self::DateInner) -> u8 {
date.0.months_in_year()
Self::months_in_provided_year(date.0.year)
}

fn days_in_year(&self, date: &Self::DateInner) -> u16 {
date.0.days_in_year()
if self.is_in_leap_year(date) {
366
} else {
365
}
}

fn days_in_month(&self, date: &Self::DateInner) -> u8 {
date.0.days_in_month()
Self::days_in_provided_month(date.0.year, date.0.month)
}

fn add(
Expand All @@ -216,7 +197,7 @@ impl Calendar for Coptic {
}

fn year_info(&self, date: &Self::DateInner) -> Self::Year {
let year = date.0.extended_year();
let year = date.0.year;
types::EraYear {
era: tinystr!(16, "am"),
era_index: Some(0),
Expand All @@ -227,19 +208,19 @@ impl Calendar for Coptic {
}

fn is_in_leap_year(&self, date: &Self::DateInner) -> bool {
Self::provided_year_is_leap(date.0.year)
date.0.year.rem_euclid(4) == 3
}

fn month(&self, date: &Self::DateInner) -> types::MonthInfo {
self.month_code_from_ordinal(&date.0.year, date.0.month)
}

fn day_of_month(&self, date: &Self::DateInner) -> types::DayOfMonth {
date.0.day_of_month()
types::DayOfMonth(date.0.day)
}

fn day_of_year(&self, date: &Self::DateInner) -> types::DayOfYear {
date.0.day_of_year()
types::DayOfYear(30 * (date.0.month as u16 - 1) + date.0.day as u16)
}

fn debug_name(&self) -> &'static str {
Expand Down
10 changes: 9 additions & 1 deletion components/calendar/src/cal/ethiopian.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -76,6 +76,14 @@ impl DateFieldsResolver for Ethiopian {
// Coptic year
type YearInfo = i32;

fn days_in_provided_month(year: Self::YearInfo, month: u8) -> u8 {
Coptic::days_in_provided_month(year, month)
}

fn months_in_provided_year(year: Self::YearInfo) -> u8 {
Coptic::months_in_provided_year(year)
}

#[inline]
fn year_info_from_era(
&self,
Expand Down Expand Up @@ -187,7 +195,7 @@ impl Calendar for Ethiopian {
}

fn year_info(&self, date: &Self::DateInner) -> Self::Year {
let coptic_year = date.0 .0.extended_year();
let coptic_year = date.0 .0.year;
let extended_year = if self.0 == EthiopianEraStyle::AmeteAlem {
coptic_year - AMETE_ALEM_OFFSET
} else {
Expand Down
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