packages/core/src/temporal/TemporalAdjusters.js
/*
* @copyright (c) 2016, Philipp Thürwächter & Pattrick Hüper
* @copyright (c) 2007-present, Stephen Colebourne & Michael Nascimento Santos
* @license BSD-3-Clause (see LICENSE in the root directory of this source tree)
*/
import { requireNonNull } from '../assert';
import { IllegalStateException } from '../errors';
import { TemporalAdjuster } from './TemporalAdjuster';
import { ChronoField } from '../temporal/ChronoField';
import { ChronoUnit } from '../temporal/ChronoUnit';
import { MathUtil } from '../MathUtil';
/**
* Common implementations of {@link TemporalAdjuster}.
*
* This class provides common implementations of {@link TemporalAdjuster}.
* They are especially useful to document the intent of business logic and
* often link well to requirements.
* For example, these two pieces of code do the same thing, but the second
* one is clearer (assuming that there is a static import of this class):
* <pre>
* // direct manipulation
* date.withDayOfMonth(1).plusMonths(1).minusDays(1);
* // use of an adjuster from this class
* date.with(lastDayOfMonth());
* </pre>
* There are two equivalent ways of using a {@link TemporalAdjuster}.
* The first is to invoke the method on the interface directly.
* The second is to use {@link Temporal#with}:
* <pre>
* // these two lines are equivalent, but the second approach is recommended
* dateTime = adjuster.adjustInto(dateTime);
* dateTime = dateTime.with(adjuster);
* </pre>
* It is recommended to use the second approach, {@link with},
* as it is a lot clearer to read in code.
*
* ### Specification for implementors
*
* This is a thread-safe utility class.
* All returned adjusters are immutable and thread-safe.
*
* The JDK 8 ofDateAdjuster(UnaryOperator) method is not backported.
*/
export class TemporalAdjusters {
//-----------------------------------------------------------------------
/**
* Returns the 'first day of month' adjuster, which returns a new date set to
* the first day of the current month.
*
* The ISO calendar system behaves as follows:
*
* * The input 2011-01-15 will return 2011-01-01.
* * The input 2011-02-15 will return 2011-02-01.
*
* The behavior is suitable for use with most calendar systems.
* It is equivalent to:
* <pre>
* temporal.with(DAY_OF_MONTH, 1);
* </pre>
*
* @return {TemporalAdjuster} the first day-of-month adjuster, not null
*/
static firstDayOfMonth() {
return Impl.FIRST_DAY_OF_MONTH;
}
/**
* Returns the 'last day of month' adjuster, which returns a new date set to
* the last day of the current month.
*
* The ISO calendar system behaves as follows:
*
* * The input 2011-01-15 will return 2011-01-31.
* * The input 2011-02-15 will return 2011-02-28.
* * The input 2012-02-15 will return 2012-02-29 (leap year).
* * The input 2011-04-15 will return 2011-04-30.
*
* The behavior is suitable for use with most calendar systems.
* It is equivalent to:
* <pre>
* long lastDay = temporal.range(DAY_OF_MONTH).getMaximum();
* temporal.with(DAY_OF_MONTH, lastDay);
* </pre>
*
* @return {TemporalAdjuster} the last day-of-month adjuster, not null
*/
static lastDayOfMonth() {
return Impl.LAST_DAY_OF_MONTH;
}
/**
* Returns the 'first day of next month' adjuster, which returns a new date set to
* the first day of the next month.
*
* The ISO calendar system behaves as follows:
*
* * The input 2011-01-15 will return 2011-02-01.
* * The input 2011-02-15 will return 2011-03-01.
*
* The behavior is suitable for use with most calendar systems.
* It is equivalent to:
* <pre>
* temporal.with(DAY_OF_MONTH, 1).plus(1, MONTHS);
* </pre>
*
* @return {TemporalAdjuster} the first day of next month adjuster, not null
*/
static firstDayOfNextMonth() {
return Impl.FIRST_DAY_OF_NEXT_MONTH;
}
//-----------------------------------------------------------------------
/**
* Returns the 'first day of year' adjuster, which returns a new date set to
* the first day of the current year.
*
* The ISO calendar system behaves as follows:
*
* * The input 2011-01-15 will return 2011-01-01.
* * The input 2011-02-15 will return 2011-01-01.
*
* The behavior is suitable for use with most calendar systems.
* It is equivalent to:
* <pre>
* temporal.with(DAY_OF_YEAR, 1);
* </pre>
*
* @return {TemporalAdjuster} the first day-of-year adjuster, not null
*/
static firstDayOfYear() {
return Impl.FIRST_DAY_OF_YEAR;
}
/**
* Returns the 'last day of year' adjuster, which returns a new date set to
* the last day of the current year.
*
* The ISO calendar system behaves as follows:
*
* * The input 2011-01-15 will return 2011-12-31.
* * The input 2011-02-15 will return 2011-12-31.
*
* The behavior is suitable for use with most calendar systems.
* It is equivalent to:
* <pre>
* long lastDay = temporal.range(DAY_OF_YEAR).getMaximum();
* temporal.with(DAY_OF_YEAR, lastDay);
* </pre>
*
* @return {TemporalAdjuster} the last day-of-year adjuster, not null
*/
static lastDayOfYear() {
return Impl.LAST_DAY_OF_YEAR;
}
/**
* Returns the 'first day of next year' adjuster, which returns a new date set to
* the first day of the next year.
*
* The ISO calendar system behaves as follows:
*
* * The input 2011-01-15 will return 2012-01-01.
*
* The behavior is suitable for use with most calendar systems.
* It is equivalent to:
* <pre>
* temporal.with(DAY_OF_YEAR, 1).plus(1, YEARS);
* </pre>
*
* @return {TemporalAdjuster} the first day of next month adjuster, not null
*/
static firstDayOfNextYear() {
return Impl.FIRST_DAY_OF_NEXT_YEAR;
}
//-----------------------------------------------------------------------
/**
* Returns the first in month adjuster, which returns a new date
* in the same month with the first matching day-of-week.
* This is used for expressions like 'first Tuesday in March'.
*
* The ISO calendar system behaves as follows:
*
* * The input 2011-12-15 for (MONDAY) will return 2011-12-05.
* * The input 2011-12-15 for (FRIDAY) will return 2011-12-02.
*
* The behavior is suitable for use with most calendar systems.
* It uses the {@link DAY_OF_WEEK} and {@link DAY_OF_MONTH} fields
* and the {@link DAYS} unit, and assumes a seven day week.
*
* @param {DayOfWeek} dayOfWeek the day-of-week, not null
* @return {TemporalAdjuster} the first in month adjuster, not null
*/
static firstInMonth(dayOfWeek) {
requireNonNull(dayOfWeek, 'dayOfWeek');
return new DayOfWeekInMonth(1, dayOfWeek);
}
/**
* Returns the last in month adjuster, which returns a new date
* in the same month with the last matching day-of-week.
* This is used for expressions like 'last Tuesday in March'.
*
* The ISO calendar system behaves as follows:
*
* * The input 2011-12-15 for (MONDAY) will return 2011-12-26.
* * The input 2011-12-15 for (FRIDAY) will return 2011-12-30.
*
* The behavior is suitable for use with most calendar systems.
* It uses the {@link DAY_OF_WEEK} and {@link DAY_OF_MONTH} fields
* and the {@link DAYS} unit, and assumes a seven day week.
*
* @param {DayOfWeek} dayOfWeek the day-of-week, not null
* @return {TemporalAdjuster} the first in month adjuster, not null
*/
static lastInMonth(dayOfWeek) {
requireNonNull(dayOfWeek, 'dayOfWeek');
return new DayOfWeekInMonth(-1, dayOfWeek);
}
/**
* Returns the day-of-week in month adjuster, which returns a new date
* in the same month with the ordinal day-of-week.
* This is used for expressions like the 'second Tuesday in March'.
*
* The ISO calendar system behaves as follows:
*
* * The input 2011-12-15 for (1,TUESDAY) will return 2011-12-06.
* * The input 2011-12-15 for (2,TUESDAY) will return 2011-12-13.
* * The input 2011-12-15 for (3,TUESDAY) will return 2011-12-20.
* * The input 2011-12-15 for (4,TUESDAY) will return 2011-12-27.
* * The input 2011-12-15 for (5,TUESDAY) will return 2012-01-03.
* * The input 2011-12-15 for (-1,TUESDAY) will return 2011-12-27 (last in month).
* * The input 2011-12-15 for (-4,TUESDAY) will return 2011-12-06 (3 weeks before last in month).
* * The input 2011-12-15 for (-5,TUESDAY) will return 2011-11-29 (4 weeks before last in month).
* * The input 2011-12-15 for (0,TUESDAY) will return 2011-11-29 (last in previous month).
*
* For a positive or zero ordinal, the algorithm is equivalent to finding the first
* day-of-week that matches within the month and then adding a number of weeks to it.
* For a negative ordinal, the algorithm is equivalent to finding the last
* day-of-week that matches within the month and then subtracting a number of weeks to it.
* The ordinal number of weeks is not validated and is interpreted leniently
* according to this algorithm. This definition means that an ordinal of zero finds
* the last matching day-of-week in the previous month.
*
* The behavior is suitable for use with most calendar systems.
* It uses the {@link DAY_OF_WEEK} and {@link DAY_OF_MONTH} fields
* and the {@link DAYS} unit, and assumes a seven day week.
*
* @param {Number} ordinal the week within the month, unbounded but typically from -5 to 5
* @param {DayOfWeek} dayOfWeek the day-of-week, not null
* @return {TemporalAdjuster} the day-of-week in month adjuster, not null
*/
static dayOfWeekInMonth(ordinal, dayOfWeek) {
requireNonNull(dayOfWeek, 'dayOfWeek');
return new DayOfWeekInMonth(ordinal, dayOfWeek);
}
//-----------------------------------------------------------------------
/**
* Returns the next day-of-week adjuster, which adjusts the date to the
* first occurrence of the specified day-of-week after the date being adjusted.
*
* The ISO calendar system behaves as follows:
*
* * The input 2011-01-15 (a Saturday) for parameter (MONDAY) will return 2011-01-17 (two days later).
* * The input 2011-01-15 (a Saturday) for parameter (WEDNESDAY) will return 2011-01-19 (four days later).
* * The input 2011-01-15 (a Saturday) for parameter (SATURDAY) will return 2011-01-22 (seven days later).
*
* The behavior is suitable for use with most calendar systems.
* It uses the {@link DAY_OF_WEEK} field and the {@link DAYS} unit,
* and assumes a seven day week.
*
* @param {DayOfWeek} dayOfWeek the day-of-week to move the date to, not null
* @return {TemporalAdjuster} the next day-of-week adjuster, not null
*/
static next(dayOfWeek) {
return new RelativeDayOfWeek(2, dayOfWeek);
}
/**
* Returns the next-or-same day-of-week adjuster, which adjusts the date to the
* first occurrence of the specified day-of-week after the date being adjusted
* unless it is already on that day in which case the same object is returned.
*
* The ISO calendar system behaves as follows:
*
* * The input 2011-01-15 (a Saturday) for parameter (MONDAY) will return 2011-01-17 (two days later).
* * The input 2011-01-15 (a Saturday) for parameter (WEDNESDAY) will return 2011-01-19 (four days later).
* * The input 2011-01-15 (a Saturday) for parameter (SATURDAY) will return 2011-01-15 (same as input).
*
* The behavior is suitable for use with most calendar systems.
* It uses the {@link DAY_OF_WEEK} field and the {@link DAYS} unit,
* and assumes a seven day week.
*
* @param {DayOfWeek} dayOfWeek the day-of-week to check for or move the date to, not null
* @return {TemporalAdjuster} the next-or-same day-of-week adjuster, not null
*/
static nextOrSame(dayOfWeek) {
return new RelativeDayOfWeek(0, dayOfWeek);
}
/**
* Returns the previous day-of-week adjuster, which adjusts the date to the
* first occurrence of the specified day-of-week before the date being adjusted.
*
* The ISO calendar system behaves as follows:
*
* * The input 2011-01-15 (a Saturday) for parameter (MONDAY) will return 2011-01-10 (five days earlier).
* * The input 2011-01-15 (a Saturday) for parameter (WEDNESDAY) will return 2011-01-12 (three days earlier).
* * The input 2011-01-15 (a Saturday) for parameter (SATURDAY) will return 2011-01-08 (seven days earlier).
*
* The behavior is suitable for use with most calendar systems.
* It uses the {@link DAY_OF_WEEK} field and the {@link DAYS} unit,
* and assumes a seven day week.
*
* @param {DayOfWeek} dayOfWeek the day-of-week to move the date to, not null
* @return {TemporalAdjuster} the previous day-of-week adjuster, not null
*/
static previous(dayOfWeek) {
return new RelativeDayOfWeek(3, dayOfWeek);
}
/**
* Returns the previous-or-same day-of-week adjuster, which adjusts the date to the
* first occurrence of the specified day-of-week before the date being adjusted
* unless it is already on that day in which case the same object is returned.
*
* The ISO calendar system behaves as follows:
*
* * The input 2011-01-15 (a Saturday) for parameter (MONDAY) will return 2011-01-10 (five days earlier).
* * The input 2011-01-15 (a Saturday) for parameter (WEDNESDAY) will return 2011-01-12 (three days earlier).
* * The input 2011-01-15 (a Saturday) for parameter (SATURDAY) will return 2011-01-15 (same as input).
*
* The behavior is suitable for use with most calendar systems.
* It uses the {@link DAY_OF_WEEK} field and the {@link DAYS} unit,
* and assumes a seven day week.
*
* @param {DayOfWeek} dayOfWeek the day-of-week to check for or move the date to, not null
* @return {TemporalAdjuster} the previous-or-same day-of-week adjuster, not null
*/
static previousOrSame(dayOfWeek) {
return new RelativeDayOfWeek(1, dayOfWeek);
}
}
//-----------------------------------------------------------------------
/**
* Enum implementing the adjusters.
*/
class Impl extends TemporalAdjuster {
/**
*
* @param ordinal
* @private
*/
constructor(ordinal) {
super();
this._ordinal = ordinal;
}
adjustInto(temporal) {
switch (this._ordinal) {
case 0: return temporal.with(ChronoField.DAY_OF_MONTH, 1);
case 1: return temporal.with(ChronoField.DAY_OF_MONTH, temporal.range(ChronoField.DAY_OF_MONTH).maximum());
case 2: return temporal.with(ChronoField.DAY_OF_MONTH, 1).plus(1, ChronoUnit.MONTHS);
case 3: return temporal.with(ChronoField.DAY_OF_YEAR, 1);
case 4: return temporal.with(ChronoField.DAY_OF_YEAR, temporal.range(ChronoField.DAY_OF_YEAR).maximum());
case 5: return temporal.with(ChronoField.DAY_OF_YEAR, 1).plus(1, ChronoUnit.YEARS);
}
throw new IllegalStateException('Unreachable');
}
}
/** First day of month adjuster. */
Impl.FIRST_DAY_OF_MONTH = new Impl(0);
/** Last day of month adjuster. */
Impl.LAST_DAY_OF_MONTH = new Impl(1);
/** First day of next month adjuster. */
Impl.FIRST_DAY_OF_NEXT_MONTH = new Impl(2);
/** First day of year adjuster. */
Impl.FIRST_DAY_OF_YEAR = new Impl(3);
/** Last day of year adjuster. */
Impl.LAST_DAY_OF_YEAR = new Impl(4);
/** First day of next month adjuster. */
Impl.FIRST_DAY_OF_NEXT_YEAR = new Impl(5);
/**
* Class implementing day-of-week in month adjuster.
*/
class DayOfWeekInMonth extends TemporalAdjuster {
/**
*
* @param ordinal
* @param dow
* @private
*/
constructor(ordinal, dow) {
super();
this._ordinal = ordinal;
this._dowValue = dow.value();
}
adjustInto(temporal) {
if (this._ordinal >= 0) {
const temp = temporal.with(ChronoField.DAY_OF_MONTH, 1);
const curDow = temp.get(ChronoField.DAY_OF_WEEK);
let dowDiff = MathUtil.intMod((this._dowValue - curDow + 7), 7);
dowDiff += (this._ordinal - 1) * 7; // safe from overflow
return temp.plus(dowDiff, ChronoUnit.DAYS);
} else {
const temp = temporal.with(ChronoField.DAY_OF_MONTH, temporal.range(ChronoField.DAY_OF_MONTH).maximum());
const curDow = temp.get(ChronoField.DAY_OF_WEEK);
let daysDiff = this._dowValue - curDow;
daysDiff = (daysDiff === 0 ? 0 : (daysDiff > 0 ? daysDiff - 7 : daysDiff));
daysDiff -= (-this._ordinal - 1) * 7; // safe from overflow
return temp.plus(daysDiff, ChronoUnit.DAYS);
}
}
}
/**
* Implementation of next, previous or current day-of-week.
*/
class RelativeDayOfWeek extends TemporalAdjuster {
/**
*
* @param relative
* @param dayOfWeek
* @private
*/
constructor(relative, dayOfWeek) {
super();
requireNonNull(dayOfWeek, 'dayOfWeek');
/** Whether the current date is a valid answer. */
this._relative = relative;
/** The day-of-week value, from 1 to 7. */
this._dowValue = dayOfWeek.value();
}
adjustInto(temporal) {
const calDow = temporal.get(ChronoField.DAY_OF_WEEK);
if (this._relative < 2 && calDow === this._dowValue) {
return temporal;
}
if ((this._relative & 1) === 0) {
const daysDiff = calDow - this._dowValue;
return temporal.plus(daysDiff >= 0 ? 7 - daysDiff : -daysDiff, ChronoUnit.DAYS);
} else {
const daysDiff = this._dowValue - calDow;
return temporal.minus(daysDiff >= 0 ? 7 - daysDiff : -daysDiff, ChronoUnit.DAYS);
}
}
}
