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	/*
	* Copyright (c) 2012, 2015, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
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	* version 2 for more details (a copy is included in the LICENSE file that
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	/*
	* This file is available under and governed by the GNU General Public
	* License version 2 only, as published by the Free Software Foundation.
	* However, the following notice accompanied the original version of this
	* file:
	*
	* Copyright (c) 2012, Stephen Colebourne & Michael Nascimento Santos
	*
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are met:
	*
	* * Redistributions of source code must retain the above copyright notice,
	* this list of conditions and the following disclaimer.
	*
	* * Redistributions in binary form must reproduce the above copyright notice,
	* this list of conditions and the following disclaimer in the documentation
	* and/or other materials provided with the distribution.
	*
	* * Neither the name of JSR-310 nor the names of its contributors
	* may be used to endorse or promote products derived from this software
	* without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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	* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/
	package java.time.temporal;

	import java.time.DateTimeException;

	/**
	* Framework-level interface defining read-write access to a temporal object,
	* such as a date, time, offset or some combination of these.
	* <p>
	* This is the base interface type for date, time and offset objects that
	* are complete enough to be manipulated using plus and minus.
	* It is implemented by those classes that can provide and manipulate information
	* as {@linkplain TemporalField fields} or {@linkplain TemporalQuery queries}.
	* See {@link TemporalAccessor} for the read-only version of this interface.
	* <p>
	* Most date and time information can be represented as a number.
	* These are modeled using {@code TemporalField} with the number held using
	* a {@code long} to handle large values. Year, month and day-of-month are
	* simple examples of fields, but they also include instant and offsets.
	* See {@link ChronoField} for the standard set of fields.
	* <p>
	* Two pieces of date/time information cannot be represented by numbers,
	* the {@linkplain java.time.chrono.Chronology chronology} and the
	* {@linkplain java.time.ZoneId time-zone}.
	* These can be accessed via {@link #query(TemporalQuery) queries} using
	* the static methods defined on {@link TemporalQuery}.
	* <p>
	* This interface is a framework-level interface that should not be widely
	* used in application code. Instead, applications should create and pass
	* around instances of concrete types, such as {@code LocalDate}.
	* There are many reasons for this, part of which is that implementations
	* of this interface may be in calendar systems other than ISO.
	* See {@link java.time.chrono.ChronoLocalDate} for a fuller discussion of the issues.
	*
	* <h3>When to implement</h3>
	* <p>
	* A class should implement this interface if it meets three criteria:
	* <ul>
	* <li>it provides access to date/time/offset information, as per {@code TemporalAccessor}
	* <li>the set of fields are contiguous from the largest to the smallest
	* <li>the set of fields are complete, such that no other field is needed to define the
	* valid range of values for the fields that are represented
	* </ul>
	* <p>
	* Four examples make this clear:
	* <ul>
	* <li>{@code LocalDate} implements this interface as it represents a set of fields
	* that are contiguous from days to forever and require no external information to determine
	* the validity of each date. It is therefore able to implement plus/minus correctly.
	* <li>{@code LocalTime} implements this interface as it represents a set of fields
	* that are contiguous from nanos to within days and require no external information to determine
	* validity. It is able to implement plus/minus correctly, by wrapping around the day.
	* <li>{@code MonthDay}, the combination of month-of-year and day-of-month, does not implement
	* this interface. While the combination is contiguous, from days to months within years,
	* the combination does not have sufficient information to define the valid range of values
	* for day-of-month. As such, it is unable to implement plus/minus correctly.
	* <li>The combination day-of-week and day-of-month ("Friday the 13th") should not implement
	* this interface. It does not represent a contiguous set of fields, as days to weeks overlaps
	* days to months.
	* </ul>
	*
	* @implSpec
	* This interface places no restrictions on the mutability of implementations,
	* however immutability is strongly recommended.
	* All implementations must be {@link Comparable}.
	*
	* @since 1.8
	*/
	public interface Temporal extends TemporalAccessor {

	/**
	* Checks if the specified unit is supported.
	* <p>
	* This checks if the specified unit can be added to, or subtracted from, this date-time.
	* If false, then calling the {@link #plus(long, TemporalUnit)} and
	* {@link #minus(long, TemporalUnit) minus} methods will throw an exception.
	*
	* @implSpec
	* Implementations must check and handle all units defined in {@link ChronoUnit}.
	* If the unit is supported, then true must be returned, otherwise false must be returned.
	* <p>
	* If the field is not a {@code ChronoUnit}, then the result of this method
	* is obtained by invoking {@code TemporalUnit.isSupportedBy(Temporal)}
	* passing {@code this} as the argument.
	* <p>
	* Implementations must ensure that no observable state is altered when this
	* read-only method is invoked.
	*
	* @param unit the unit to check, null returns false
	* @return true if the unit can be added/subtracted, false if not
	*/
	boolean isSupported(TemporalUnit unit);

	/**
	* Returns an adjusted object of the same type as this object with the adjustment made.
	* <p>
	* This adjusts this date-time according to the rules of the specified adjuster.
	* A simple adjuster might simply set the one of the fields, such as the year field.
	* A more complex adjuster might set the date to the last day of the month.
	* A selection of common adjustments is provided in
	* {@link java.time.temporal.TemporalAdjusters TemporalAdjusters}.
	* These include finding the "last day of the month" and "next Wednesday".
	* The adjuster is responsible for handling special cases, such as the varying
	* lengths of month and leap years.
	* <p>
	* Some example code indicating how and why this method is used:
	* <pre>
	* date = date.with(Month.JULY); // most key classes implement TemporalAdjuster
	* date = date.with(lastDayOfMonth()); // static import from Adjusters
	* date = date.with(next(WEDNESDAY)); // static import from Adjusters and DayOfWeek
	* </pre>
	*
	* @implSpec
	* <p>
	* Implementations must not alter either this object or the specified temporal object.
	* Instead, an adjusted copy of the original must be returned.
	* This provides equivalent, safe behavior for immutable and mutable implementations.
	* <p>
	* The default implementation must behave equivalent to this code:
	* <pre>
	* return adjuster.adjustInto(this);
	* </pre>
	*
	* @param adjuster the adjuster to use, not null
	* @return an object of the same type with the specified adjustment made, not null
	* @throws DateTimeException if unable to make the adjustment
	* @throws ArithmeticException if numeric overflow occurs
	*/
	default Temporal with(TemporalAdjuster adjuster) {
	return adjuster.adjustInto(this);
	}

	/**
	* Returns an object of the same type as this object with the specified field altered.
	* <p>
	* This returns a new object based on this one with the value for the specified field changed.
	* For example, on a {@code LocalDate}, this could be used to set the year, month or day-of-month.
	* The returned object will have the same observable type as this object.
	* <p>
	* In some cases, changing a field is not fully defined. For example, if the target object is
	* a date representing the 31st January, then changing the month to February would be unclear.
	* In cases like this, the field is responsible for resolving the result. Typically it will choose
	* the previous valid date, which would be the last valid day of February in this example.
	*
	* @implSpec
	* Implementations must check and handle all fields defined in {@link ChronoField}.
	* If the field is supported, then the adjustment must be performed.
	* If unsupported, then an {@code UnsupportedTemporalTypeException} must be thrown.
	* <p>
	* If the field is not a {@code ChronoField}, then the result of this method
	* is obtained by invoking {@code TemporalField.adjustInto(Temporal, long)}
	* passing {@code this} as the first argument.
	* <p>
	* Implementations must not alter this object.
	* Instead, an adjusted copy of the original must be returned.
	* This provides equivalent, safe behavior for immutable and mutable implementations.
	*
	* @param field the field to set in the result, not null
	* @param newValue the new value of the field in the result
	* @return an object of the same type with the specified field set, not null
	* @throws DateTimeException if the field cannot be set
	* @throws UnsupportedTemporalTypeException if the field is not supported
	* @throws ArithmeticException if numeric overflow occurs
	*/
	Temporal with(TemporalField field, long newValue);

	//-----------------------------------------------------------------------
	/**
	* Returns an object of the same type as this object with an amount added.
	* <p>
	* This adjusts this temporal, adding according to the rules of the specified amount.
	* The amount is typically a {@link java.time.Period} but may be any other type implementing
	* the {@link TemporalAmount} interface, such as {@link java.time.Duration}.
	* <p>
	* Some example code indicating how and why this method is used:
	* <pre>
	* date = date.plus(period); // add a Period instance
	* date = date.plus(duration); // add a Duration instance
	* date = date.plus(workingDays(6)); // example user-written workingDays method
	* </pre>
	* <p>
	* Note that calling {@code plus} followed by {@code minus} is not guaranteed to
	* return the same date-time.
	*
	* @implSpec
	* <p>
	* Implementations must not alter either this object or the specified temporal object.
	* Instead, an adjusted copy of the original must be returned.
	* This provides equivalent, safe behavior for immutable and mutable implementations.
	* <p>
	* The default implementation must behave equivalent to this code:
	* <pre>
	* return amount.addTo(this);
	* </pre>
	*
	* @param amount the amount to add, not null
	* @return an object of the same type with the specified adjustment made, not null
	* @throws DateTimeException if the addition cannot be made
	* @throws ArithmeticException if numeric overflow occurs
	*/
	default Temporal plus(TemporalAmount amount) {
	return amount.addTo(this);
	}

	/**
	* Returns an object of the same type as this object with the specified period added.
	* <p>
	* This method returns a new object based on this one with the specified period added.
	* For example, on a {@code LocalDate}, this could be used to add a number of years, months or days.
	* The returned object will have the same observable type as this object.
	* <p>
	* In some cases, changing a field is not fully defined. For example, if the target object is
	* a date representing the 31st January, then adding one month would be unclear.
	* In cases like this, the field is responsible for resolving the result. Typically it will choose
	* the previous valid date, which would be the last valid day of February in this example.
	*
	* @implSpec
	* Implementations must check and handle all units defined in {@link ChronoUnit}.
	* If the unit is supported, then the addition must be performed.
	* If unsupported, then an {@code UnsupportedTemporalTypeException} must be thrown.
	* <p>
	* If the unit is not a {@code ChronoUnit}, then the result of this method
	* is obtained by invoking {@code TemporalUnit.addTo(Temporal, long)}
	* passing {@code this} as the first argument.
	* <p>
	* Implementations must not alter this object.
	* Instead, an adjusted copy of the original must be returned.
	* This provides equivalent, safe behavior for immutable and mutable implementations.
	*
	* @param amountToAdd the amount of the specified unit to add, may be negative
	* @param unit the unit of the amount to add, not null
	* @return an object of the same type with the specified period added, not null
	* @throws DateTimeException if the unit cannot be added
	* @throws UnsupportedTemporalTypeException if the unit is not supported
	* @throws ArithmeticException if numeric overflow occurs
	*/
	Temporal plus(long amountToAdd, TemporalUnit unit);

	//-----------------------------------------------------------------------
	/**
	* Returns an object of the same type as this object with an amount subtracted.
	* <p>
	* This adjusts this temporal, subtracting according to the rules of the specified amount.
	* The amount is typically a {@link java.time.Period} but may be any other type implementing
	* the {@link TemporalAmount} interface, such as {@link java.time.Duration}.
	* <p>
	* Some example code indicating how and why this method is used:
	* <pre>
	* date = date.minus(period); // subtract a Period instance
	* date = date.minus(duration); // subtract a Duration instance
	* date = date.minus(workingDays(6)); // example user-written workingDays method
	* </pre>
	* <p>
	* Note that calling {@code plus} followed by {@code minus} is not guaranteed to
	* return the same date-time.
	*
	* @implSpec
	* <p>
	* Implementations must not alter either this object or the specified temporal object.
	* Instead, an adjusted copy of the original must be returned.
	* This provides equivalent, safe behavior for immutable and mutable implementations.
	* <p>
	* The default implementation must behave equivalent to this code:
	* <pre>
	* return amount.subtractFrom(this);
	* </pre>
	*
	* @param amount the amount to subtract, not null
	* @return an object of the same type with the specified adjustment made, not null
	* @throws DateTimeException if the subtraction cannot be made
	* @throws ArithmeticException if numeric overflow occurs
	*/
	default Temporal minus(TemporalAmount amount) {
	return amount.subtractFrom(this);
	}

	/**
	* Returns an object of the same type as this object with the specified period subtracted.
	* <p>
	* This method returns a new object based on this one with the specified period subtracted.
	* For example, on a {@code LocalDate}, this could be used to subtract a number of years, months or days.
	* The returned object will have the same observable type as this object.
	* <p>
	* In some cases, changing a field is not fully defined. For example, if the target object is
	* a date representing the 31st March, then subtracting one month would be unclear.
	* In cases like this, the field is responsible for resolving the result. Typically it will choose
	* the previous valid date, which would be the last valid day of February in this example.
	*
	* @implSpec
	* Implementations must behave in a manor equivalent to the default method behavior.
	* <p>
	* Implementations must not alter this object.
	* Instead, an adjusted copy of the original must be returned.
	* This provides equivalent, safe behavior for immutable and mutable implementations.
	* <p>
	* The default implementation must behave equivalent to this code:
	* <pre>
	* return (amountToSubtract == Long.MIN_VALUE ?
	* plus(Long.MAX_VALUE, unit).plus(1, unit) : plus(-amountToSubtract, unit));
	* </pre>
	*
	* @param amountToSubtract the amount of the specified unit to subtract, may be negative
	* @param unit the unit of the amount to subtract, not null
	* @return an object of the same type with the specified period subtracted, not null
	* @throws DateTimeException if the unit cannot be subtracted
	* @throws UnsupportedTemporalTypeException if the unit is not supported
	* @throws ArithmeticException if numeric overflow occurs
	*/
	default Temporal minus(long amountToSubtract, TemporalUnit unit) {
	return (amountToSubtract == Long.MIN_VALUE ? plus(Long.MAX_VALUE, unit).plus(1, unit) : plus(-amountToSubtract, unit));
	}

	//-----------------------------------------------------------------------
	/**
	* Calculates the amount of time until another temporal in terms of the specified unit.
	* <p>
	* This calculates the amount of time between two temporal objects
	* in terms of a single {@code TemporalUnit}.
	* The start and end points are {@code this} and the specified temporal.
	* The end point is converted to be of the same type as the start point if different.
	* The result will be negative if the end is before the start.
	* For example, the amount in hours between two temporal objects can be
	* calculated using {@code startTime.until(endTime, HOURS)}.
	* <p>
	* The calculation returns a whole number, representing the number of
	* complete units between the two temporals.
	* For example, the amount in hours between the times 11:30 and 13:29
	* will only be one hour as it is one minute short of two hours.
	* <p>
	* There are two equivalent ways of using this method.
	* The first is to invoke this method directly.
	* The second is to use {@link TemporalUnit#between(Temporal, Temporal)}:
	* <pre>
	* // these two lines are equivalent
	* temporal = start.until(end, unit);
	* temporal = unit.between(start, end);
	* </pre>
	* The choice should be made based on which makes the code more readable.
	* <p>
	* For example, this method allows the number of days between two dates to
	* be calculated:
	* <pre>
	* long daysBetween = start.until(end, DAYS);
	* // or alternatively
	* long daysBetween = DAYS.between(start, end);
	* </pre>
	*
	* @implSpec
	* Implementations must begin by checking to ensure that the input temporal
	* object is of the same observable type as the implementation.
	* They must then perform the calculation for all instances of {@link ChronoUnit}.
	* An {@code UnsupportedTemporalTypeException} must be thrown for {@code ChronoUnit}
	* instances that are unsupported.
	* <p>
	* If the unit is not a {@code ChronoUnit}, then the result of this method
	* is obtained by invoking {@code TemporalUnit.between(Temporal, Temporal)}
	* passing {@code this} as the first argument and the converted input temporal as
	* the second argument.
	* <p>
	* In summary, implementations must behave in a manner equivalent to this pseudo-code:
	* <pre>
	* // convert the end temporal to the same type as this class
	* if (unit instanceof ChronoUnit) {
	* // if unit is supported, then calculate and return result
	* // else throw UnsupportedTemporalTypeException for unsupported units
	* }
	* return unit.between(this, convertedEndTemporal);
	* </pre>
	* <p>
	* Note that the unit's {@code between} method must only be invoked if the
	* two temporal objects have exactly the same type evaluated by {@code getClass()}.
	* <p>
	* Implementations must ensure that no observable state is altered when this
	* read-only method is invoked.
	*
	* @param endExclusive the end temporal, exclusive, converted to be of the
	* same type as this object, not null
	* @param unit the unit to measure the amount in, not null
	* @return the amount of time between this temporal object and the specified one
	* in terms of the unit; positive if the specified object is later than this one,
	* negative if it is earlier than this one
	* @throws DateTimeException if the amount cannot be calculated, or the end
	* temporal cannot be converted to the same type as this temporal
	* @throws UnsupportedTemporalTypeException if the unit is not supported
	* @throws ArithmeticException if numeric overflow occurs
	*/
	long until(Temporal endExclusive, TemporalUnit unit);

	}

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