概述

本包提供了一组组件，用于描述重复事件属性和行为。

本包的典型用法是创建一个重复事件，定义其重复规则（例如，每个星期二发生，每月的15日发生）然后从事件中获取符合规则的下一个日期。

当前支持四种周期性（每日、每周、每月和每年），通过四种类型： DailyEvent，WeeklyEvent，MonthlyEvent 和 YearlyEvent。

使用年度事件的示例

use recurring_event::{YearlyEvent, Ordinal, Recurrent, MonthlyWeekdayOrdinal,
    time::{Month, OffsetDateTime, Weekday, macros::datetime}};

// This yearly event starts recurring on the 14th of November 2018.
let mut event = YearlyEvent::new(datetime!(2018-11-14 00:00 UTC));

// It's an event that recurs every four years.
event.update_frequency(4);

// On a year, the event happens on every Monday and Thursday of February.
event.insert_weekday(Weekday::Monday, Month::February);
event.insert_weekday(Weekday::Thursday, Month::February);

// And also on the 7th and 15th of February.
event.insert_monthly_day_ordinal(7, Month::February);
event.insert_monthly_day_ordinal(25, Month::February);

// And also on the second Tuesday and the last Sunday of February.
event.insert_monthly_weekday_ordinal(
    MonthlyWeekdayOrdinal::new(Ordinal::Second, Weekday::Tuesday),
    Month::February);
event.insert_monthly_weekday_ordinal(
    MonthlyWeekdayOrdinal::new(Ordinal::Last, Weekday::Sunday),
    Month::February);

// The event also happens on August, every Tuesday and Saturday.
event.insert_weekday(Weekday::Tuesday, Month::August);
event.insert_weekday(Weekday::Saturday, Month::August);

// And on the 13th and 29th of August.
event.insert_monthly_day_ordinal(13, Month::August);
event.insert_monthly_day_ordinal(29, Month::August);

// And on the first Wednesday and third Friday of August.
event.insert_monthly_weekday_ordinal(
    MonthlyWeekdayOrdinal::new(Ordinal::First, Weekday::Wednesday),
    Month::August);
event.insert_monthly_weekday_ordinal(
    MonthlyWeekdayOrdinal::new(Ordinal::Third, Weekday::Friday),
    Month::August);

// One possibility for getting the next occurrence dates is to take
// advantage of the fact that a YearlyEvent implement the Iterator trait.
// Let's get the next fourty occurrence dates !
let next_occurrences_dates: Vec<OffsetDateTime> = event.take(40).collect();

let expected_dates = vec![datetime!(2022-02-03 00:00 UTC),
    datetime!(2022-02-07 00:00 UTC),
    datetime!(2022-02-08 00:00 UTC),
    datetime!(2022-02-10 00:00 UTC),
    datetime!(2022-02-14 00:00 UTC),
    datetime!(2022-02-17 00:00 UTC),
    datetime!(2022-02-21 00:00 UTC),
    datetime!(2022-02-24 00:00 UTC),
    datetime!(2022-02-25 00:00 UTC),
    datetime!(2022-02-27 00:00 UTC),
    datetime!(2022-02-28 00:00 UTC),
    datetime!(2022-08-02 00:00 UTC),
    datetime!(2022-08-03 00:00 UTC),
    datetime!(2022-08-06 00:00 UTC),
    datetime!(2022-08-09 00:00 UTC),
    datetime!(2022-08-13 00:00 UTC),
    datetime!(2022-08-16 00:00 UTC),
    datetime!(2022-08-19 00:00 UTC),
    datetime!(2022-08-20 00:00 UTC),
    datetime!(2022-08-23 00:00 UTC),
    datetime!(2022-08-27 00:00 UTC),
    datetime!(2022-08-29 00:00 UTC),
    datetime!(2022-08-30 00:00 UTC),
    datetime!(2026-02-02 00:00 UTC),
    datetime!(2026-02-05 00:00 UTC),
    datetime!(2026-02-07 00:00 UTC),
    datetime!(2026-02-09 00:00 UTC),
    datetime!(2026-02-10 00:00 UTC),
    datetime!(2026-02-12 00:00 UTC),
    datetime!(2026-02-16 00:00 UTC),
    datetime!(2026-02-19 00:00 UTC),
    datetime!(2026-02-22 00:00 UTC),
    datetime!(2026-02-23 00:00 UTC),
    datetime!(2026-02-25 00:00 UTC),
    datetime!(2026-02-26 00:00 UTC),
    datetime!(2026-08-01 00:00 UTC),
    datetime!(2026-08-04 00:00 UTC),
    datetime!(2026-08-05 00:00 UTC),
    datetime!(2026-08-08 00:00 UTC),
    datetime!(2026-08-11 00:00 UTC)];

assert_eq!(expected_dates, next_occurrences_dates)

time 包

本包使用 time 包，特别是 OffsetDateTime，Month 和 Weekday 类型。

OffsetDateTime 存储时间和偏移量信息（即时区）。目前，本包没有使用它们。它可用于您的代码，如果您需要管理事件中的特定时间和偏移量。

serde 和 typetag 包

（反）序列化事件类型得益于 serde，以及（反）序列化 Box<dyn Recurrent> 特征对象得益于 typetag。