packages/core/src/YearMonth.js
/*
* @copyright (c) 2016, Philipp Thürwächter & Pattrick Hüper
* @license BSD-3-Clause (see LICENSE.md in the root directory of this source tree)
*/
import { requireNonNull, requireInstance } from './assert';
import { DateTimeException, UnsupportedTemporalTypeException } from './errors';
import { MathUtil } from './MathUtil';
import { ChronoField } from './temporal/ChronoField';
import { ChronoUnit } from './temporal/ChronoUnit';
import { Clock } from './Clock';
import { DateTimeFormatterBuilder } from './format/DateTimeFormatterBuilder';
import { IsoChronology } from './chrono/IsoChronology';
import { LocalDate } from './LocalDate';
import { Month } from './Month';
import { SignStyle } from './format/SignStyle';
import { Temporal } from './temporal/Temporal';
import { TemporalField } from './temporal/TemporalField';
import { TemporalQueries } from './temporal/TemporalQueries';
import { TemporalQuery } from './temporal/TemporalQuery';
import { TemporalUnit } from './temporal/TemporalUnit';
import { createTemporalQuery } from './temporal/TemporalQuery';
import { ValueRange } from './temporal/ValueRange';
import { Year } from './Year';
import { ZoneId } from './ZoneId';
/**
* A year-month in the ISO-8601 calendar system, such as `2007-12`.
*
* {@link YearMonth} is an immutable date-time object that represents the combination
* of a year and month. Any field that can be derived from a year and month, such as
* quarter-of-year, can be obtained.
*
* This class does not store or represent a day, time or time-zone.
* For example, the value "October 2007" can be stored in a {@link YearMonth}.
*
* The ISO-8601 calendar system is the modern civil calendar system used today
* in most of the world. It is equivalent to the proleptic Gregorian calendar
* system, in which today's rules for leap years are applied for all time.
* For most applications written today, the ISO-8601 rules are entirely suitable.
* However, any application that makes use of historical dates, and requires them
* to be accurate will find the ISO-8601 approach unsuitable.
*
* ### Specification for implementors
*
* This class is immutable and thread-safe.
*/
export class YearMonth extends Temporal {
//-----------------------------------------------------------------------
/**
* function overloading for {@link YearMonth.now}
*
* if called with 0 argument {@link YearMonth.now0} is executed,
*
* if called with 1 argument and first argument is an instance of ZoneId, then {@link YearMonth.nowZoneId} is executed,
*
* otherwise {@link YearMonth.nowClock} is executed
*
* @param {?(ZoneId|Clock)} zoneIdOrClock
* @returns {YearMonth}
*/
static now(zoneIdOrClock) {
if (arguments.length === 0) {
return YearMonth.now0();
} else if (arguments.length === 1 && zoneIdOrClock instanceof ZoneId) {
return YearMonth.nowZoneId(zoneIdOrClock);
} else {
return YearMonth.nowClock(zoneIdOrClock);
}
}
/**
* Obtains the current year-month from the system clock in the default time-zone.
*
* This will query the system clock (see {@link Clock#systemDefaultZone}) in the default
* time-zone to obtain the current year-month.
* The zone and offset will be set based on the time-zone in the clock.
*
* Using this method will prevent the ability to use an alternate clock for testing
* because the clock is hard-coded.
*
* @return {YearMonth} the current year-month using the system clock and default time-zone, not null
*/
static now0() {
return YearMonth.nowClock(Clock.systemDefaultZone());
}
/**
* Obtains the current year-month from the system clock in the specified time-zone.
*
* This will query the system clock (see {@link Clock#system}) to obtain the current year-month.
* Specifying the time-zone avoids dependence on the default time-zone.
*
* Using this method will prevent the ability to use an alternate clock for testing
* because the clock is hard-coded.
*
* @param {ZoneId} zone the zone ID to use, not null
* @return {YearMonth} the current year-month using the system clock, not null
*/
static nowZoneId(zone) {
return YearMonth.nowClock(Clock.system(zone));
}
/**
* Obtains the current year-month from the specified clock.
*
* This will query the specified clock to obtain the current year-month.
* Using this method allows the use of an alternate clock for testing.
* The alternate clock may be introduced using dependency injection.
*
* @param {Clock} clock the clock to use, not null
* @return {YearMonth} the current year-month, not null
*/
static nowClock(clock) {
const now = LocalDate.now(clock);
return YearMonth.of(now.year(), now.month());
}
//-----------------------------------------------------------------------
/**
* function overloading for {@link YearMonth.of}
*
* if called with 2 argument and first argument is an instance of Month, then {@link YearMonth.ofNumberMonth} is executed,
*
* otherwise {@link YearMonth.ofNumberNumber} is executed
*
* @param {!number} year
* @param {!(Month|number)} monthOrNumber
* @returns {YearMonth}
*/
static of(year, monthOrNumber) {
if (arguments.length === 2 && monthOrNumber instanceof Month) {
return YearMonth.ofNumberMonth(year, monthOrNumber);
} else {
return YearMonth.ofNumberNumber(year, monthOrNumber);
}
}
/**
* Obtains an instance of {@link YearMonth} from a year and month.
*
* @param {number} year the year to represent, from MIN_YEAR to MAX_YEAR
* @param {Month} month the month-of-year to represent, not null
* @return {YearMonth} the year-month, not null
* @throws DateTimeException if the year value is invalid
*/
static ofNumberMonth(year, month) {
requireNonNull(month, 'month');
requireInstance(month, Month, 'month');
return YearMonth.ofNumberNumber(year, month.value());
}
/**
* Obtains an instance of {@link YearMonth} from a year and month.
*
* @param {number} year the year to represent, from MIN_YEAR to MAX_YEAR
* @param {number} month the month-of-year to represent, from 1 (January) to 12 (December)
* @return {YearMonth} the year-month, not null
* @throws DateTimeException if either field value is invalid
*/
static ofNumberNumber(year, month) {
requireNonNull(year, 'year');
requireNonNull(month, 'month');
ChronoField.YEAR.checkValidValue(year);
ChronoField.MONTH_OF_YEAR.checkValidValue(month);
return new YearMonth(year, month);
}
//-----------------------------------------------------------------------
/**
* Obtains an instance of {@link YearMonth} from a temporal object.
*
* A {@link TemporalAccessor} represents some form of date and time information.
* This factory converts the arbitrary temporal object to an instance of {@link YearMonth}.
*
* The conversion extracts the {@link ChronoField#YEAR} and
* {@link ChronoField#MONTH_OF_YEAR} fields.
* The extraction is only permitted if the temporal object has an ISO
* chronology, or can be converted to a {@link LocalDate}.
*
* This method matches the signature of the functional interface {@link TemporalQuery}
* allowing it to be used in queries via method reference, {@link YearMonth::from}.
*
* @param {TemporalAccessor} temporal the temporal object to convert, not null
* @return {YearMonth} the year-month, not null
* @throws DateTimeException if unable to convert to a {@link YearMonth}
*/
static from(temporal) {
requireNonNull(temporal, 'temporal');
if (temporal instanceof YearMonth) {
return temporal;
}
try {
/* TODO: only IsoChronology for now
if (IsoChronology.INSTANCE.equals(Chronology.from(temporal)) == false) {
temporal = LocalDate.from(temporal);
}*/
return YearMonth.of(temporal.get(ChronoField.YEAR), temporal.get(ChronoField.MONTH_OF_YEAR));
} catch (ex) {
throw new DateTimeException(`Unable to obtain YearMonth from TemporalAccessor: ${
temporal}, type ${temporal && temporal.constructor != null ? temporal.constructor.name : ''}`);
}
}
//-----------------------------------------------------------------------
/**
* function overloading for {@link YearMonth.parse}
*
* if called with 2 argument and first argument is an instance of Month, then {@link YearMonth.parseString} is executed,
*
* otherwise {@link YearMonth.parseStringFormatter} is executed
*
* @param {!(String)} text
* @param {?DateTimeFormatter} formatter
* @returns {YearMonth}
*/
static parse(text, formatter) {
if (arguments.length === 1) {
return YearMonth.parseString(text);
} else {
return YearMonth.parseStringFormatter(text, formatter);
}
}
/**
* Obtains an instance of {@link YearMonth} from a text string such as `2007-12`.
*
* The string must represent a valid year-month.
* The format must be {@link yyyy-MM}.
* Years outside the range 0000 to 9999 must be prefixed by the plus or minus symbol.
*
* @param {String} text the text to parse such as "2007-12", not null
* @return {YearMonth} the parsed year-month, not null
* @throws DateTimeParseException if the text cannot be parsed
*/
static parseString(text) {
return YearMonth.parseStringFormatter(text, PARSER);
}
/**
* Obtains an instance of {@link YearMonth} from a text string using a specific formatter.
*
* The text is parsed using the formatter, returning a year-month.
*
* @param {String} text the text to parse, not null
* @param {DateTimeFormatter} formatter the formatter to use, not null
* @return the parsed year-month, not null
* @throws DateTimeParseException if the text cannot be parsed
*/
static parseStringFormatter(text, formatter) {
requireNonNull(formatter, 'formatter');
return formatter.parse(text, YearMonth.FROM);
}
/**
* Constructor.
*
* @param {number} year the year to represent, validated from MIN_YEAR to MAX_YEAR
* @param {number} month the month-of-year to represent, validated from 1 (January) to 12 (December)
* @private
*/
constructor(year, month) {
super();
this._year = MathUtil.safeToInt(year);
this._month = MathUtil.safeToInt(month);
}
/**
* function overloading for {@link YearMonth.isSupported}
*
* if called with 1 argument and first argument is an instance of TemporalField, then {@link YearMonth.isSupportedField} is executed,
*
* otherwise {@link YearMonth.isSupportedUnit} is executed
*
* @param {!(TemporalField|ChronoUnit)} fieldOrUnit
* @returns {boolean}
*/
isSupported(fieldOrUnit) {
if (arguments.length === 1 && fieldOrUnit instanceof TemporalField) {
return this.isSupportedField(fieldOrUnit);
} else {
return this.isSupportedUnit(fieldOrUnit);
}
}
/**
* Checks if the specified field is supported.
*
* This checks if this year-month can be queried for the specified field.
* If false, then calling {@link range} and {@link get} will throw an exception.
*
* If the field is a {@link ChronoField} then the query is implemented here.
* The supported fields (see {@link isSupported}) will return valid
* values based on this date-time.
* The supported fields are:
*
* * {@link MONTH_OF_YEAR}
* * {@link EPOCH_MONTH}
* * {@link YEAR_OF_ERA}
* * {@link YEAR}
* * {@link ERA}
*
* All other {@link ChronoField} instances will return false.
*
* If the field is not a {@link ChronoField}, then the result of this method
* is obtained by invoking {@link TemporalField.isSupportedBy}
* passing `this` as the argument.
* Whether the field is supported is determined by the field.
*
* @param {TemporalField} field the field to check, null returns false
* @return {boolean} true if the field is supported on this year-month, false if not
*/
isSupportedField(field) {
if (field instanceof ChronoField) {
return field === ChronoField.YEAR || field === ChronoField.MONTH_OF_YEAR ||
field === ChronoField.PROLEPTIC_MONTH || field === ChronoField.YEAR_OF_ERA || field === ChronoField.ERA;
}
return field != null && field.isSupportedBy(this);
}
isSupportedUnit(unit) {
if (unit instanceof ChronoUnit) {
return unit === ChronoUnit.MONTHS || unit === ChronoUnit.YEARS || unit === ChronoUnit.DECADES || unit === ChronoUnit.CENTURIES || unit === ChronoUnit.MILLENNIA || unit === ChronoUnit.ERAS;
}
return unit != null && unit.isSupportedBy(this);
}
/**
* Gets the range of valid values for the specified field.
*
* The range object expresses the minimum and maximum valid values for a field.
* This year-month is used to enhance the accuracy of the returned range.
* If it is not possible to return the range, because the field is not supported
* or for some other reason, an exception is thrown.
*
* If the field is a {@link ChronoField} then the query is implemented here.
* The supported fields (see {@link isSupported}) will return
* appropriate range instances.
* All other {@link ChronoField} instances will throw a {@link DateTimeException}.
*
* If the field is not a {@link ChronoField}, then the result of this method
* is obtained by invoking {@link TemporalField.rangeRefinedBy}
* passing `this` as the argument.
* Whether the range can be obtained is determined by the field.
*
* @param {TemporalField} field the field to query the range for, not null
* @return {ValueRange} the range of valid values for the field, not null
* @throws DateTimeException if the range for the field cannot be obtained
*/
range(field) {
if (field === ChronoField.YEAR_OF_ERA) {
return (this.year() <= 0 ? ValueRange.of(1, Year.MAX_VALUE + 1) : ValueRange.of(1, Year.MAX_VALUE));
}
return super.range(field);
}
/**
* Gets the value of the specified field from this year-month as an `int`.
*
* This queries this year-month for the value for the specified field.
* The returned value will always be within the valid range of values for the field.
* If it is not possible to return the value, because the field is not supported
* or for some other reason, an exception is thrown.
*
* If the field is a {@link ChronoField} then the query is implemented here.
* The supported fields (see {@link isSupported}) will return valid
* values based on this year-month, except {@link EPOCH_MONTH} which is too
* large to fit in an `int` and throw a {@link DateTimeException}.
* All other {@link ChronoField} instances will throw a {@link DateTimeException}.
*
* If the field is not a {@link ChronoField}, then the result of this method
* is obtained by invoking {@link TemporalField.getFrom}
* passing `this` as the argument. Whether the value can be obtained,
* and what the value represents, is determined by the field.
*
* @param {TemporalField} field the field to get, not null
* @return {number} the value for the field
* @throws DateTimeException if a value for the field cannot be obtained
* @throws ArithmeticException if numeric overflow occurs
*/
get(field) {
requireNonNull(field, 'field');
requireInstance(field, TemporalField, 'field');
return this.range(field).checkValidIntValue(this.getLong(field), field);
}
/**
* Gets the value of the specified field from this year-month as a `long`.
*
* This queries this year-month for the value for the specified field.
* If it is not possible to return the value, because the field is not supported
* or for some other reason, an exception is thrown.
*
* If the field is a {@link ChronoField} then the query is implemented here.
* The supported fields (see {@link isSupported}) will return valid
* values based on this year-month.
* All other {@link ChronoField} instances will throw a {@link DateTimeException}.
*
* If the field is not a {@link ChronoField}, then the result of this method
* is obtained by invoking {@link TemporalField.getFrom}
* passing `this` as the argument. Whether the value can be obtained,
* and what the value represents, is determined by the field.
*
* @param {TemporalField} field the field to get, not null
* @return {number} the value for the field
* @throws DateTimeException if a value for the field cannot be obtained
* @throws ArithmeticException if numeric overflow occurs
*/
getLong(field) {
requireNonNull(field, 'field');
requireInstance(field, TemporalField, 'field');
if (field instanceof ChronoField) {
switch (field) {
case ChronoField.MONTH_OF_YEAR: return this._month;
case ChronoField.PROLEPTIC_MONTH: return this._getProlepticMonth();
case ChronoField.YEAR_OF_ERA: return (this._year < 1 ? 1 - this._year : this._year);
case ChronoField.YEAR: return this._year;
case ChronoField.ERA: return (this._year < 1 ? 0 : 1);
}
throw new UnsupportedTemporalTypeException(`Unsupported field: ${field}`);
}
return field.getFrom(this);
}
_getProlepticMonth() {
return MathUtil.safeAdd(MathUtil.safeMultiply(this._year, 12), (this._month - 1));
}
//-----------------------------------------------------------------------
/**
* Gets the year field.
*
* This method returns the primitive `int` value for the year.
*
* The year returned by this method is proleptic as per {@link get}.
*
* @return {number} the year, from MIN_YEAR to MAX_YEAR
*/
year() {
return this._year;
}
/**
* Gets the month-of-year field from 1 to 12.
*
* This method returns the month as an `int` from 1 to 12.
* Application code is frequently clearer if the enum {@link Month}
* is used by calling {@link getMonth}.
*
* @return {number} the month-of-year, from 1 to 12
* @see #getMonth()
*/
monthValue() {
return this._month;
}
/**
* Gets the month-of-year field using the {@link Month} enum.
*
* This method returns the enum {@link Month} for the month.
* This avoids confusion as to what `int` values mean.
* If you need access to the primitive `int` value, use {@link Month#getValue}.
*
* @return {Month} the month-of-year, not null
*/
month() {
return Month.of(this._month);
}
//-----------------------------------------------------------------------
/**
* Checks if the year is a leap year, according to the ISO proleptic
* calendar system rules.
*
* This method applies the current rules for leap years across the whole time-line.
* In general, a year is a leap year if it is divisible by four without
* remainder. However, years divisible by 100, are not leap years, with
* the exception of years divisible by 400 which are.
*
* For example, 1904 is a leap year it is divisible by 4.
* 1900 was not a leap year as it is divisible by 100, however 2000 was a
* leap year as it is divisible by 400.
*
* The calculation is proleptic - applying the same rules into the far future and far past.
* This is historically inaccurate, but is correct for the ISO-8601 standard.
*
* @return {boolean} true if the year is leap, false otherwise
*/
isLeapYear() {
return IsoChronology.isLeapYear(this._year);
}
/**
* Checks if the day-of-month is valid for this year-month.
*
* This method checks whether this year and month and the input day form
* a valid date.
*
* @param {number} dayOfMonth the day-of-month to validate, from 1 to 31, invalid value returns false
* @return {boolean} true if the day is valid for this year-month
*/
isValidDay(dayOfMonth) {
return dayOfMonth >= 1 && dayOfMonth <= this.lengthOfMonth();
}
/**
* Returns the length of the month, taking account of the year.
*
* This returns the length of the month in days.
* For example, a date in January would return 31.
*
* @return {number} the length of the month in days, from 28 to 31
*/
lengthOfMonth() {
return this.month().length(this.isLeapYear());
}
/**
* Returns the length of the year.
*
* This returns the length of the year in days, either 365 or 366.
*
* @return {number} 366 if the year is leap, 365 otherwise
*/
lengthOfYear() {
return (this.isLeapYear() ? 366 : 365);
}
/**
* function overloading for {@link YearMonth.with}
*
* if called with 1 argument, then {@link YearMonth.withAdjuster} is executed,
* otherwise {@link YearMonth.withFieldValue} is executed.
*
* @param {!(TemporalAdjuster|TemporalField)} adjusterOrField
* @param {?number} value nullable only of first argument is an instance of TemporalAdjuster
* @returns {YearMonth}
*/
with(adjusterOrField, value) {
if (arguments.length === 1) {
return this._withAdjuster(adjusterOrField);
} else {
return this._withField(adjusterOrField, value);
}
}
/**
* Returns a copy of this year-month with the specified field set to a new value.
*
* This returns a new {@link YearMonth}, based on this one, with the value
* for the specified field changed.
* This can be used to change any supported field, such as the year or month.
* If it is not possible to set the value, because the field is not supported or for
* some other reason, an exception is thrown.
*
* If the field is a {@link ChronoField} then the adjustment is implemented here.
* The supported fields behave as follows:
*
* * {@link MONTH_OF_YEAR} -
* Returns a {@link YearMonth} with the specified month-of-year.
* The year will be unchanged.
* * {@link PROLEPTIC_MONTH} -
* Returns a {@link YearMonth} with the specified proleptic-month.
* This completely replaces the year and month of this object.
* * {@link YEAR_OF_ERA} -
* Returns a {@link YearMonth} with the specified year-of-era
* The month and era will be unchanged.
* * {@link YEAR} -
* Returns a {@link YearMonth} with the specified year.
* The month will be unchanged.
* * {@link ERA} -
* Returns a {@link YearMonth} with the specified era.
* The month and year-of-era will be unchanged.
*
* In all cases, if the new value is outside the valid range of values for the field
* then a {@link DateTimeException} will be thrown.
*
* All other {@link ChronoField} instances will throw a {@link DateTimeException}.
*
* If the field is not a {@link ChronoField}, then the result of this method
* is obtained by invoking {@link TemporalField.adjustInto}
* passing `this` as the argument. In this case, the field determines
* whether and how to adjust the instant.
*
* This instance is immutable and unaffected by this method call.
*
* @param {TemporalField} field the field to set in the result, not null
* @param {number} newValue the new value of the field in the result
* @return a {@link YearMonth} based on `this` with the specified field set, not null
* @throws DateTimeException if the field cannot be set
* @throws ArithmeticException if numeric overflow occurs
*/
_withField(field, newValue) {
requireNonNull(field, 'field');
requireInstance(field, TemporalField, 'field');
if (field instanceof ChronoField) {
const f = field;
f.checkValidValue(newValue);
switch (f) {
case ChronoField.MONTH_OF_YEAR: return this.withMonth(newValue);
case ChronoField.PROLEPTIC_MONTH: return this.plusMonths(newValue - this.getLong(ChronoField.PROLEPTIC_MONTH));
case ChronoField.YEAR_OF_ERA: return this.withYear((this._year < 1 ? 1 - newValue : newValue));
case ChronoField.YEAR: return this.withYear(newValue);
case ChronoField.ERA: return (this.getLong(ChronoField.ERA) === newValue ? this : this.withYear(1 - this._year));
}
throw new UnsupportedTemporalTypeException(`Unsupported field: ${field}`);
}
return field.adjustInto(this, newValue);
}
//-----------------------------------------------------------------------
/**
* Returns a copy of this {@link YearMonth} with the year altered.
*
* This instance is immutable and unaffected by this method call.
*
* @param {number} year the year to set in the returned year-month, from MIN_YEAR to MAX_YEAR
* @return {YearMonth} based on this year-month with the requested year, not null
* @throws DateTimeException if the year value is invalid
*/
withYear(year) {
ChronoField.YEAR.checkValidValue(year);
return new YearMonth(year, this._month);
}
/**
* Returns a copy of this {@link YearMonth} with the month-of-year altered.
*
* This instance is immutable and unaffected by this method call.
*
* @param {number} month the month-of-year to set in the returned year-month, from 1 (January) to 12 (December)
* @return {YearMonth} based on this year-month with the requested month, not null
* @throws DateTimeException if the month-of-year value is invalid
*/
withMonth(month) {
ChronoField.MONTH_OF_YEAR.checkValidValue(month);
return new YearMonth(this._year, month);
}
//-----------------------------------------------------------------------
/**
* @param {number} amountToAdd
* @param {TemporalUnit} unit
* @return {YearMonth} based on this year-month with the addition made, not null
* @throws DateTimeException if the addition cannot be made
* @throws ArithmeticException if numeric overflow occurs
*/
_plusUnit(amountToAdd, unit) {
requireNonNull(unit, 'unit');
requireInstance(unit, TemporalUnit, 'unit');
if (unit instanceof ChronoUnit) {
switch (unit) {
case ChronoUnit.MONTHS: return this.plusMonths(amountToAdd);
case ChronoUnit.YEARS: return this.plusYears(amountToAdd);
case ChronoUnit.DECADES: return this.plusYears(MathUtil.safeMultiply(amountToAdd, 10));
case ChronoUnit.CENTURIES: return this.plusYears(MathUtil.safeMultiply(amountToAdd, 100));
case ChronoUnit.MILLENNIA: return this.plusYears(MathUtil.safeMultiply(amountToAdd, 1000));
case ChronoUnit.ERAS: return this.with(ChronoField.ERA, MathUtil.safeAdd(this.getLong(ChronoField.ERA), amountToAdd));
}
throw new UnsupportedTemporalTypeException(`Unsupported unit: ${unit}`);
}
return unit.addTo(this, amountToAdd);
}
/**
* Returns a copy of this year-month with the specified period in years added.
*
* This instance is immutable and unaffected by this method call.
*
* @param {number} yearsToAdd the years to add, may be negative
* @return {YearMonth} based on this year-month with the years added, not null
* @throws DateTimeException if the result exceeds the supported range
*/
plusYears(yearsToAdd) {
if (yearsToAdd === 0) {
return this;
}
const newYear = ChronoField.YEAR.checkValidIntValue(this._year + yearsToAdd); // safe overflow
return this.withYear(newYear);
}
/**
* Returns a copy of this year-month with the specified period in months added.
*
* This instance is immutable and unaffected by this method call.
*
* @param {number} monthsToAdd the months to add, may be negative
* @return {YearMonth} based on this year-month with the months added, not null
* @throws DateTimeException if the result exceeds the supported range
*/
plusMonths(monthsToAdd) {
if (monthsToAdd === 0) {
return this;
}
const monthCount = (this._year * 12) + (this._month - 1);
const calcMonths = monthCount + monthsToAdd;
const newYear = ChronoField.YEAR.checkValidIntValue(MathUtil.floorDiv(calcMonths, 12));
const newMonth = MathUtil.floorMod(calcMonths, 12) + 1;
return new YearMonth(newYear, newMonth);
}
//-----------------------------------------------------------------------
/**
* Returns a copy of this year-month with the specified period in years subtracted.
*
* This instance is immutable and unaffected by this method call.
*
* @param {number} yearsToSubtract the years to subtract, may be negative
* @return {YearMonth} based on this year-month with the years subtracted, not null
* @throws DateTimeException if the result exceeds the supported range
*/
minusYears(yearsToSubtract) {
return (yearsToSubtract === MathUtil.MIN_SAFE_INTEGER ? this.plusYears(MathUtil.MIN_SAFE_INTEGER).plusYears(1) : this.plusYears(-yearsToSubtract));
}
/**
* Returns a copy of this year-month with the specified period in months subtracted.
*
* This instance is immutable and unaffected by this method call.
*
* @param {number} monthsToSubtract the months to subtract, may be negative
* @return {YearMonth} based on this year-month with the months subtracted, not null
* @throws DateTimeException if the result exceeds the supported range
*/
minusMonths(monthsToSubtract) {
return (monthsToSubtract === MathUtil.MIN_SAFE_INTEGER ? this.plusMonths(Math.MAX_SAFE_INTEGER).plusMonths(1) : this.plusMonths(-monthsToSubtract));
}
//-----------------------------------------------------------------------
/**
* Queries this year-month using the specified query.
*
* This queries this year-month using the specified query strategy object.
* The {@link TemporalQuery} object defines the logic to be used to
* obtain the result. Read the documentation of the query to understand
* what the result of this method will be.
*
* The result of this method is obtained by invoking the
* {@link TemporalQuery#queryFrom} method on the
* specified query passing `this` as the argument.
*
* @param {TemporalQuery} query the query to invoke, not null
* @return {*} the query result, null may be returned (defined by the query)
* @throws DateTimeException if unable to query (defined by the query)
* @throws ArithmeticException if numeric overflow occurs (defined by the query)
*/
query(query) {
requireNonNull(query, 'query');
requireInstance(query, TemporalQuery, 'query');
if (query === TemporalQueries.chronology()) {
return IsoChronology.INSTANCE;
} else if (query === TemporalQueries.precision()) {
return ChronoUnit.MONTHS;
} else if (query === TemporalQueries.localDate() || query === TemporalQueries.localTime() ||
query === TemporalQueries.zone() || query === TemporalQueries.zoneId() || query === TemporalQueries.offset()) {
return null;
}
return super.query(query);
}
/**
* Adjusts the specified temporal object to have this year-month.
*
* This returns a temporal object of the same observable type as the input
* with the year and month changed to be the same as this.
*
* The adjustment is equivalent to using {@link Temporal#with}
* passing {@link ChronoField#PROLEPTIC_MONTH} as the field.
* If the specified temporal object does not use the ISO calendar system then
* a {@link DateTimeException} is thrown.
*
* In most cases, it is clearer to reverse the calling pattern by using
* {@link Temporal#with}:
* <pre>
* // these two lines are equivalent, but the second approach is recommended
* temporal = thisYearMonth.adjustInto(temporal);
* temporal = temporal.with(thisYearMonth);
* </pre>
*
* This instance is immutable and unaffected by this method call.
*
* @param {Temporal} temporal the target object to be adjusted, not null
* @return {Temporal} the adjusted object, not null
* @throws DateTimeException if unable to make the adjustment
* @throws ArithmeticException if numeric overflow occurs
*/
adjustInto(temporal) {
requireNonNull(temporal, 'temporal');
requireInstance(temporal, Temporal, 'temporal');
/* TODO: only IsoChronology for now
if (Chronology.from(temporal).equals(IsoChronology.INSTANCE) == false) {
throw new DateTimeException("Adjustment only supported on ISO date-time");
}*/
return temporal.with(ChronoField.PROLEPTIC_MONTH, this._getProlepticMonth());
}
/**
* Calculates the period between this year-month and another year-month in
* terms of the specified unit.
*
* This calculates the period between two year-months in terms of a single unit.
* The start and end points are `this` and the specified year-month.
* The result will be negative if the end is before the start.
* The {@link Temporal} passed to this method must be a {@link YearMonth}.
* For example, the period in years between two year-months can be calculated
* using {@link startYearMonth.until}.
*
* The calculation returns a whole number, representing the number of
* complete units between the two year-months.
* For example, the period in decades between 2012-06 and 2032-05
* will only be one decade as it is one month short of two decades.
*
* This method operates in association with {@link TemporalUnit#between}.
* The result of this method is a `long` representing the amount of
* the specified unit. By contrast, the result of {@link between} is an
* object that can be used directly in addition/subtraction:
* <pre>
* long period = start.until(end, YEARS); // this method
* dateTime.plus(YEARS.between(start, end)); // use in plus/minus
* </pre>
*
* The calculation is implemented in this method for {@link ChronoUnit}.
* The units {@link MONTHS}, {@link YEARS}, {@link DECADES},
* {@link CENTURIES}, {@link MILLENNIA} and {@link ERAS} are supported.
* Other {@link ChronoUnit} values will throw an exception.
*
* If the unit is not a {@link ChronoUnit}, then the result of this method
* is obtained by invoking {@link TemporalUnit.between}
* passing `this` as the first argument and the input temporal as
* the second argument.
*
* This instance is immutable and unaffected by this method call.
*
* @param {Temporal} endExclusive the end year-month, which is converted to a {@link YearMonth}, not null
* @param {TemporalUnit} unit the unit to measure the period in, not null
* @return {number} the amount of the period between this year-month and the end year-month
* @throws DateTimeException if the period cannot be calculated
* @throws ArithmeticException if numeric overflow occurs
*/
until(endExclusive, unit) {
requireNonNull(endExclusive, 'endExclusive');
requireNonNull(unit, 'unit');
requireInstance(endExclusive, Temporal, 'endExclusive');
requireInstance(unit, TemporalUnit, 'unit');
const end = YearMonth.from(endExclusive);
if (unit instanceof ChronoUnit) {
const monthsUntil = end._getProlepticMonth() - this._getProlepticMonth(); // no overflow
switch (unit) {
case ChronoUnit.MONTHS: return monthsUntil;
case ChronoUnit.YEARS: return MathUtil.intDiv(monthsUntil, 12);
case ChronoUnit.DECADES: return MathUtil.intDiv(monthsUntil, 120);
case ChronoUnit.CENTURIES: return MathUtil.intDiv(monthsUntil, 1200);
case ChronoUnit.MILLENNIA: return MathUtil.intDiv(monthsUntil, 12000);
case ChronoUnit.ERAS: return end.getLong(ChronoField.ERA) - this.getLong(ChronoField.ERA);
}
throw new UnsupportedTemporalTypeException(`Unsupported unit: ${unit}`);
}
return unit.between(this, end);
}
//-----------------------------------------------------------------------
/**
* Combines this year-month with a day-of-month to create a {@link LocalDate}.
*
* This returns a {@link LocalDate} formed from this year-month and the specified day-of-month.
*
* The day-of-month value must be valid for the year-month.
*
* This method can be used as part of a chain to produce a date:
* <pre>
* LocalDate date = year.atMonth(month).atDay(day);
* </pre>
*
* @param {number} dayOfMonth the day-of-month to use, from 1 to 31
* @return {LocalDate} the date formed from this year-month and the specified day, not null
* @throws DateTimeException if the day is invalid for the year-month
* @see #isValidDay(int)
*/
atDay(dayOfMonth) {
requireNonNull(dayOfMonth, 'dayOfMonth');
return LocalDate.of(this._year, this._month, dayOfMonth);
}
/**
* Returns a {@link LocalDate} at the end of the month.
*
* This returns a {@link LocalDate} based on this year-month.
* The day-of-month is set to the last valid day of the month, taking
* into account leap years.
*
* This method can be used as part of a chain to produce a date:
* <pre>
* LocalDate date = year.atMonth(month).atEndOfMonth();
* </pre>
*
* @return {LocalDate} the last valid date of this year-month, not null
*/
atEndOfMonth() {
return LocalDate.of(this._year, this._month, this.lengthOfMonth());
}
//-----------------------------------------------------------------------
/**
* Compares this year-month to another year-month.
*
* The comparison is based first on the value of the year, then on the value of the month.
* It is "consistent with equals", as defined by {@link Comparable}.
*
* @param {YearMonth} other the other year-month to compare to, not null
* @return {number} the comparator value, negative if less, positive if greater
*/
compareTo(other) {
requireNonNull(other, 'other');
requireInstance(other, YearMonth, 'other');
let cmp = (this._year - other.year());
if (cmp === 0) {
cmp = (this._month - other.monthValue());
}
return cmp;
}
/**
* Is this year-month after the specified year-month.
*
* @param {YearMonth} other the other year-month to compare to, not null
* @return {boolean} true if this is after the specified year-month
*/
isAfter(other) {
return this.compareTo(other) > 0;
}
/**
* Is this year-month before the specified year-month.
*
* @param {YearMonth} other the other year-month to compare to, not null
* @return {boolean} true if this point is before the specified year-month
*/
isBefore(other) {
return this.compareTo(other) < 0;
}
//-----------------------------------------------------------------------
/**
* Checks if this year-month is equal to another year-month.
*
* The comparison is based on the time-line position of the year-months.
*
* @param {*} obj the object to check, null returns false
* @return {boolean} true if this is equal to the other year-month
*/
equals(obj) {
if (this === obj) {
return true;
}
if (obj instanceof YearMonth) {
const other = obj;
return this.year() === other.year() && this.monthValue() === other.monthValue();
}
return false;
}
//-----------------------------------------------------------------------
/**
* Outputs this year-month as a string, such as `2007-12`.
*
* The output will be in the format {@link yyyy-MM}:
*
* @return {String} a string representation of this year-month, not null
*/
toString() {
return PARSER.format(this);
}
/**
* toJSON() use by JSON.stringify
* delegates to toString()
*
* @return {string}
*/
toJSON() {
return this.toString();
}
/**
* Outputs this year-month as a string using the formatter.
*
* @param {DateTimeFormatter} formatter the formatter to use, not null
* @return {String} the formatted year-month string, not null
* @throws DateTimeException if an error occurs during printing
*/
format(formatter) {
requireNonNull(formatter, 'formatter');
return formatter.format(this);
}
}
let PARSER;
export function _init() {
PARSER = new DateTimeFormatterBuilder()
.appendValue(ChronoField.YEAR, 4, 10, SignStyle.EXCEEDS_PAD)
.appendLiteral('-')
.appendValue(ChronoField.MONTH_OF_YEAR, 2)
.toFormatter();
YearMonth.FROM = createTemporalQuery('YearMonth.FROM', (temporal) => {
return YearMonth.from(temporal);
});
}
