// 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
// (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
use crate::any_calendar::{AnyCalendar, IntoAnyCalendar};
use crate::week::{WeekCalculator, WeekOf};
use crate::{types, Calendar, CalendarError, DateDuration, DateDurationUnit, Iso};
use alloc::rc::Rc;
use alloc::sync::Arc;
use core::fmt;
use core::ops::Deref;
/// Types that contain a calendar
///
/// This allows one to use [`Date`] with wrappers around calendars,
/// e.g. reference counted calendars.
pub trait AsCalendar {
/// The calendar being wrapped
type Calendar: Calendar;
/// Obtain the inner calendar
fn as_calendar(&self) -> &Self::Calendar;
}
impl<C: Calendar> AsCalendar for C {
type Calendar = C;
#[inline]
fn as_calendar(&self) -> &Self {
self
}
}
impl<C: Calendar> AsCalendar for Rc<C> {
type Calendar = C;
#[inline]
fn as_calendar(&self) -> &C {
&*self
}
}
impl<C: Calendar> AsCalendar for Arc<C> {
type Calendar = C;
#[inline]
fn as_calendar(&self) -> &C {
&*self
}
}
/// This exists as a wrapper around `&'a T` so that
/// `Date<&'a C>` is possible for calendar `C`.
///
/// Unfortunately,
/// [`AsCalendar`] cannot be implemented on `&'a T` directly because
/// `&'a T` is `#[fundamental]` and the impl would clash with the one above with
/// `AsCalendar` for `C: Calendar`.
///
/// Use `Date<Ref<'a, C>>` where you would use `Date<&'a C>`
#[allow(clippy::exhaustive_structs)] // newtype
#[derive(PartialEq, Eq, Debug)]
pub struct Ref<'a, C>(pub &'a C);
impl<C> Copy for Ref<'_, C> {}
impl<C> Clone for Ref<'_, C> {
fn clone(&self) -> Self {
*self
}
}
impl<C: Calendar> AsCalendar for Ref<'_, C> {
type Calendar = C;
#[inline]
fn as_calendar(&self) -> &C {
self.0
}
}
impl<'a, C> Deref for Ref<'a, C> {
type Target = C;
fn deref(&self) -> &C {
self.0
}
}
/// A date for a given calendar.
///
/// This can work with wrappers around [`Calendar`] types,
/// e.g. `Rc<C>`, via the [`AsCalendar`] trait.
///
/// This can be constructed constructed
/// from its fields via [`Self::try_new_from_codes()`], or can be constructed with one of the
/// `new_<calendar>_datetime()` per-calendar methods (and then freely converted between calendars).
///
/// ```rust
/// use icu::calendar::Date;
///
/// // Example: creation of ISO date from integers.
/// let date_iso = Date::try_new_iso_date(1970, 1, 2)
/// .expect("Failed to initialize ISO Date instance.");
///
/// assert_eq!(date_iso.year().number, 1970);
/// assert_eq!(date_iso.month().ordinal, 1);
/// assert_eq!(date_iso.day_of_month().0, 2);
/// ```
pub struct Date<A: AsCalendar> {
pub(crate) inner: <A::Calendar as Calendar>::DateInner,
pub(crate) calendar: A,
}
impl<A: AsCalendar> Date<A> {
/// Construct a date from from era/month codes and fields, and some calendar representation
#[inline]
pub fn try_new_from_codes(
era: types::Era,
year: i32,
month_code: types::MonthCode,
day: u8,
calendar: A,
) -> Result<Self, CalendarError> {
let inner = calendar
.as_calendar()
.date_from_codes(era, year, month_code, day)?;
Ok(Date { inner, calendar })
}
/// Construct a date from an ISO date and some calendar representation
#[inline]
pub fn new_from_iso(iso: Date<Iso>, calendar: A) -> Self {
let inner = calendar.as_calendar().date_from_iso(iso);
Date { inner, calendar }
}
/// Convert the Date to an ISO Date
#[inline]
pub fn to_iso(&self) -> Date<Iso> {
self.calendar.as_calendar().date_to_iso(self.inner())
}
/// Convert the Date to a date in a different calendar
#[inline]
pub fn to_calendar<A2: AsCalendar>(&self, calendar: A2) -> Date<A2> {
Date::new_from_iso(self.to_iso(), calendar)
}
/// The number of months in the year of this date
#[inline]
pub fn months_in_year(&self) -> u8 {
self.calendar.as_calendar().months_in_year(self.inner())
}
/// The number of days in the year of this date
#[inline]
pub fn days_in_year(&self) -> u32 {
self.calendar.as_calendar().days_in_year(self.inner())
}
/// The number of days in the month of this date
#[inline]
pub fn days_in_month(&self) -> u8 {
self.calendar.as_calendar().days_in_month(self.inner())
}
/// The day of the week for this date
///
/// Monday is 1, Sunday is 7, according to ISO
#[inline]
pub fn day_of_week(&self) -> types::IsoWeekday {
self.calendar.as_calendar().day_of_week(self.inner())
}
/// Add a `duration` to this date, mutating it
///
/// Currently unstable for ICU4X 1.0
#[doc(hidden)]
#[inline]
pub fn add(&mut self, duration: DateDuration<A::Calendar>) {
self.calendar
.as_calendar()
.offset_date(&mut self.inner, duration)
}
/// Add a `duration` to this date, returning the new one
///
/// Currently unstable for ICU4X 1.0
#[doc(hidden)]
#[inline]
pub fn added(mut self, duration: DateDuration<A::Calendar>) -> Self {
self.add(duration);
self
}
/// Calculating the duration between `other - self`
///
/// Currently unstable for ICU4X 1.0
#[doc(hidden)]
#[inline]
pub fn until<B: AsCalendar<Calendar = A::Calendar>>(
&self,
other: &Date<B>,
largest_unit: DateDurationUnit,
smallest_unit: DateDurationUnit,
) -> DateDuration<A::Calendar> {
self.calendar.as_calendar().until(
self.inner(),
other.inner(),
other.calendar.as_calendar(),
largest_unit,
smallest_unit,
)
}
/// The calendar-specific year represented by `self`
#[inline]
pub fn year(&self) -> types::FormattableYear {
self.calendar.as_calendar().year(&self.inner)
}
/// The calendar-specific month represented by `self`
#[inline]
pub fn month(&self) -> types::FormattableMonth {
self.calendar.as_calendar().month(&self.inner)
}
/// The calendar-specific day-of-month represented by `self`
#[inline]
pub fn day_of_month(&self) -> types::DayOfMonth {
self.calendar.as_calendar().day_of_month(&self.inner)
}
/// The calendar-specific day-of-month represented by `self`
#[inline]
pub fn day_of_year_info(&self) -> types::DayOfYearInfo {
self.calendar.as_calendar().day_of_year_info(&self.inner)
}
/// The week of the month containing this date.
///
/// # Examples
///
/// ```
/// use icu::calendar::types::IsoWeekday;
/// use icu::calendar::types::WeekOfMonth;
/// use icu::calendar::Date;
///
/// let date = Date::try_new_iso_date(2022, 8, 10).unwrap(); // second Wednesday
///
/// // The following info is usually locale-specific
/// let first_weekday = IsoWeekday::Sunday;
///
/// assert_eq!(date.week_of_month(first_weekday), WeekOfMonth(2));
/// ```
pub fn week_of_month(&self, first_weekday: types::IsoWeekday) -> types::WeekOfMonth {
let config = WeekCalculator {
first_weekday,
min_week_days: 0, // ignored
};
config.week_of_month(self.day_of_month(), self.day_of_week())
}
/// The week of the year containing this date.
///
/// # Examples
///
/// ```
/// use icu::calendar::types::IsoWeekday;
/// use icu::calendar::week::RelativeUnit;
/// use icu::calendar::week::WeekCalculator;
/// use icu::calendar::week::WeekOf;
/// use icu::calendar::Date;
///
/// let date = Date::try_new_iso_date(2022, 8, 26).unwrap();
///
/// // The following info is usually locale-specific
/// let week_calculator = WeekCalculator::default();
///
/// assert_eq!(
/// date.week_of_year(&week_calculator),
/// Ok(WeekOf {
/// week: 35,
/// unit: RelativeUnit::Current
/// })
/// );
/// ```
pub fn week_of_year(&self, config: &WeekCalculator) -> Result<WeekOf, CalendarError> {
config.week_of_year(self.day_of_year_info(), self.day_of_week())
}
/// Construct a date from raw values for a given calendar. This does not check any
/// invariants for the date and calendar, and should only be called by calendar implementations.
///
/// Calling this outside of calendar implementations is sound, but calendar implementations are not
/// expected to do anything sensible with such invalid dates.
///
/// AnyCalendar *will* panic if AnyCalendar [`Date`] objects with mismatching
/// date and calendar types are constructed
#[inline]
pub fn from_raw(inner: <A::Calendar as Calendar>::DateInner, calendar: A) -> Self {
Self { inner, calendar }
}
/// Get the inner date implementation. Should not be called outside of calendar implementations
#[inline]
pub fn inner(&self) -> &<A::Calendar as Calendar>::DateInner {
&self.inner
}
/// Get a reference to the contained calendar
#[inline]
pub fn calendar(&self) -> &A::Calendar {
self.calendar.as_calendar()
}
/// Get a reference to the contained calendar wrapper
///
/// (Useful in case the user wishes to e.g. clone an Rc)
#[inline]
pub fn calendar_wrapper(&self) -> &A {
&self.calendar
}
}
impl<C: IntoAnyCalendar, A: AsCalendar<Calendar = C>> Date<A> {
/// Type-erase the date, converting it to a date for [`AnyCalendar`]
pub fn to_any(&self) -> Date<AnyCalendar> {
let cal = self.calendar();
Date::from_raw(cal.date_to_any(self.inner()), cal.to_any_cloned())
}
}
impl<C: Calendar> Date<C> {
/// Wrap the calendar type in `Rc<T>`
///
/// Useful when paired with [`Self::to_any()`] to obtain a `Date<Rc<AnyCalendar>>`
pub fn wrap_calendar_in_rc(self) -> Date<Rc<C>> {
Date::from_raw(self.inner, Rc::new(self.calendar))
}
/// Wrap the calendar type in `Arc<T>`
///
/// Useful when paired with [`Self::to_any()`] to obtain a `Date<Rc<AnyCalendar>>`
pub fn wrap_calendar_in_arc(self) -> Date<Arc<C>> {
Date::from_raw(self.inner, Arc::new(self.calendar))
}
}
impl<C, A, B> PartialEq<Date<B>> for Date<A>
where
C: Calendar,
A: AsCalendar<Calendar = C>,
B: AsCalendar<Calendar = C>,
{
fn eq(&self, other: &Date<B>) -> bool {
self.inner.eq(&other.inner)
}
}
impl<A: AsCalendar> Eq for Date<A> {}
impl<A: AsCalendar> fmt::Debug for Date<A> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
write!(
f,
"Date({:?}, for calendar {})",
self.inner,
self.calendar.as_calendar().debug_name()
)
}
}
impl<A: AsCalendar + Clone> Clone for Date<A> {
fn clone(&self) -> Self {
Self {
inner: self.inner.clone(),
calendar: self.calendar.clone(),
}
}
}
impl<A> Copy for Date<A>
where
A: AsCalendar + Copy,
<<A as AsCalendar>::Calendar as Calendar>::DateInner: Copy,
{
}