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	/*
	* Copyright (c) 2012, 2020, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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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
	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
	* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
	* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
	* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
	* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
	* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
	* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/
	package java.time.temporal;

	import java.time.DateTimeException;
	import java.time.chrono.Chronology;
	import java.time.format.ResolverStyle;
	import java.util.Locale;
	import java.util.Map;
	import java.util.Objects;

	/**
	* A field of date-time, such as month-of-year or minute-of-hour.
	* <p>
	* Date and time is expressed using fields which partition the time-line into something
	* meaningful for humans. Implementations of this interface represent those fields.
	* <p>
	* The most commonly used units are defined in {@link ChronoField}.
	* Further fields are supplied in {@link IsoFields}, {@link WeekFields} and {@link JulianFields}.
	* Fields can also be written by application code by implementing this interface.
	* <p>
	* The field works using double dispatch. Client code calls methods on a date-time like
	* {@code LocalDateTime} which check if the field is a {@code ChronoField}.
	* If it is, then the date-time must handle it.
	* Otherwise, the method call is re-dispatched to the matching method in this interface.
	*
	* @implSpec
	* This interface must be implemented with care to ensure other classes operate correctly.
	* All implementations that can be instantiated must be final, immutable and thread-safe.
	* Implementations should be {@code Serializable} where possible.
	* An enum is as effective implementation choice.
	*
	* @since 1.8
	*/
	public interface TemporalField {

	/**
	* Gets the display name for the field in the requested locale.
	* <p>
	* If there is no display name for the locale then a suitable default must be returned.
	* <p>
	* The default implementation must check the locale is not null
	* and return {@code toString()}.
	*
	* @param locale the locale to use, not null
	* @return the display name for the locale or a suitable default, not null
	*/
	default String getDisplayName(Locale locale) {
	Objects.requireNonNull(locale, "locale");
	return toString();
	}

	/**
	* Gets the unit that the field is measured in.
	* <p>
	* The unit of the field is the period that varies within the range.
	* For example, in the field 'MonthOfYear', the unit is 'Months'.
	* See also {@link #getRangeUnit()}.
	*
	* @return the unit defining the base unit of the field, not null
	*/
	TemporalUnit getBaseUnit();

	/**
	* Gets the range that the field is bound by.
	* <p>
	* The range of the field is the period that the field varies within.
	* For example, in the field 'MonthOfYear', the range is 'Years'.
	* See also {@link #getBaseUnit()}.
	* <p>
	* The range is never null. For example, the 'Year' field is shorthand for
	* 'YearOfForever'. It therefore has a unit of 'Years' and a range of 'Forever'.
	*
	* @return the unit defining the range of the field, not null
	*/
	TemporalUnit getRangeUnit();

	/**
	* Gets the range of valid values for the field.
	* <p>
	* All fields can be expressed as a {@code long} integer.
	* This method returns an object that describes the valid range for that value.
	* This method is generally only applicable to the ISO-8601 calendar system.
	* <p>
	* Note that the result only describes the minimum and maximum valid values
	* and it is important not to read too much into them. For example, there
	* could be values within the range that are invalid for the field.
	*
	* @return the range of valid values for the field, not null
	*/
	ValueRange range();

	//-----------------------------------------------------------------------
	/**
	* Checks if this field represents a component of a date.
	* <p>
	* A field is date-based if it can be derived from
	* {@link ChronoField#EPOCH_DAY EPOCH_DAY}.
	* Note that it is valid for both {@code isDateBased()} and {@code isTimeBased()}
	* to return false, such as when representing a field like minute-of-week.
	*
	* @return true if this field is a component of a date
	*/
	boolean isDateBased();

	/**
	* Checks if this field represents a component of a time.
	* <p>
	* A field is time-based if it can be derived from
	* {@link ChronoField#NANO_OF_DAY NANO_OF_DAY}.
	* Note that it is valid for both {@code isDateBased()} and {@code isTimeBased()}
	* to return false, such as when representing a field like minute-of-week.
	*
	* @return true if this field is a component of a time
	*/
	boolean isTimeBased();

	//-----------------------------------------------------------------------
	/**
	* Checks if this field is supported by the temporal object.
	* <p>
	* This determines whether the temporal accessor supports this field.
	* If this returns false, then the temporal cannot be queried for this field.
	* <p>
	* There are two equivalent ways of using this method.
	* The first is to invoke this method directly.
	* The second is to use {@link TemporalAccessor#isSupported(TemporalField)}:
	* <pre>
	* // these two lines are equivalent, but the second approach is recommended
	* temporal = thisField.isSupportedBy(temporal);
	* temporal = temporal.isSupported(thisField);
	* </pre>
	* It is recommended to use the second approach, {@code isSupported(TemporalField)},
	* as it is a lot clearer to read in code.
	* <p>
	* Implementations should determine whether they are supported using the fields
	* available in {@link ChronoField}.
	*
	* @param temporal the temporal object to query, not null
	* @return true if the date-time can be queried for this field, false if not
	*/
	boolean isSupportedBy(TemporalAccessor temporal);

	/**
	* Get the range of valid values for this field using the temporal object to
	* refine the result.
	* <p>
	* This uses the temporal object to find the range of valid values for the field.
	* This is similar to {@link #range()}, however this method refines the result
	* using the temporal. For example, if the field is {@code DAY_OF_MONTH} the
	* {@code range} method is not accurate as there are four possible month lengths,
	* 28, 29, 30 and 31 days. Using this method with a date allows the range to be
	* accurate, returning just one of those four options.
	* <p>
	* There are two equivalent ways of using this method.
	* The first is to invoke this method directly.
	* The second is to use {@link TemporalAccessor#range(TemporalField)}:
	* <pre>
	* // these two lines are equivalent, but the second approach is recommended
	* temporal = thisField.rangeRefinedBy(temporal);
	* temporal = temporal.range(thisField);
	* </pre>
	* It is recommended to use the second approach, {@code range(TemporalField)},
	* as it is a lot clearer to read in code.
	* <p>
	* Implementations should perform any queries or calculations using the fields
	* available in {@link ChronoField}.
	* If the field is not supported an {@code UnsupportedTemporalTypeException} must be thrown.
	*
	* @param temporal the temporal object used to refine the result, not null
	* @return the range of valid values for this field, not null
	* @throws DateTimeException if the range for the field cannot be obtained
	* @throws UnsupportedTemporalTypeException if the field is not supported by the temporal
	*/
	ValueRange rangeRefinedBy(TemporalAccessor temporal);

	/**
	* Gets the value of this field from the specified temporal object.
	* <p>
	* This queries the temporal object for the value of this field.
	* <p>
	* There are two equivalent ways of using this method.
	* The first is to invoke this method directly.
	* The second is to use {@link TemporalAccessor#getLong(TemporalField)}
	* (or {@link TemporalAccessor#get(TemporalField)}):
	* <pre>
	* // these two lines are equivalent, but the second approach is recommended
	* temporal = thisField.getFrom(temporal);
	* temporal = temporal.getLong(thisField);
	* </pre>
	* It is recommended to use the second approach, {@code getLong(TemporalField)},
	* as it is a lot clearer to read in code.
	* <p>
	* Implementations should perform any queries or calculations using the fields
	* available in {@link ChronoField}.
	* If the field is not supported an {@code UnsupportedTemporalTypeException} must be thrown.
	*
	* @param temporal the temporal object to query, not null
	* @return the value of this field, not null
	* @throws DateTimeException if a value for the field cannot be obtained
	* @throws UnsupportedTemporalTypeException if the field is not supported by the temporal
	* @throws ArithmeticException if numeric overflow occurs
	*/
	long getFrom(TemporalAccessor temporal);

	/**
	* Returns a copy of the specified temporal object with the value of this field set.
	* <p>
	* This returns a new temporal object based on the specified one with the value for
	* this field changed. For example, on a {@code LocalDate}, this could be used to
	* set the year, month or day-of-month.
	* The returned object has the same observable type as the specified 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 implementation 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.
	* <p>
	* There are two equivalent ways of using this method.
	* The first is to invoke this method directly.
	* The second is to use {@link Temporal#with(TemporalField, long)}:
	* <pre>
	* // these two lines are equivalent, but the second approach is recommended
	* temporal = thisField.adjustInto(temporal);
	* temporal = temporal.with(thisField);
	* </pre>
	* It is recommended to use the second approach, {@code with(TemporalField)},
	* as it is a lot clearer to read in code.
	* <p>
	* Implementations should perform any queries or calculations using the fields
	* available in {@link ChronoField}.
	* If the field is not supported an {@code UnsupportedTemporalTypeException} must be thrown.
	* <p>
	* Implementations must not alter the specified temporal object.
	* Instead, an adjusted copy of the original must be returned.
	* This provides equivalent, safe behavior for immutable and mutable implementations.
	*
	* @param <R> the type of the Temporal object
	* @param temporal the temporal object to adjust, not null
	* @param newValue the new value of the field
	* @return the adjusted temporal object, not null
	* @throws DateTimeException if the field cannot be set
	* @throws UnsupportedTemporalTypeException if the field is not supported by the temporal
	* @throws ArithmeticException if numeric overflow occurs
	*/
	<R extends Temporal> R adjustInto(R temporal, long newValue);

	/**
	* Resolves this field to provide a simpler alternative or a date.
	* <p>
	* This method is invoked during the resolve phase of parsing.
	* It is designed to allow application defined fields to be simplified into
	* more standard fields, such as those on {@code ChronoField}, or into a date.
	* <p>
	* Applications should not normally invoke this method directly.
	*
	* @implSpec
	* If an implementation represents a field that can be simplified, or
	* combined with others, then this method must be implemented.
	* <p>
	* The specified map contains the current state of the parse.
	* The map is mutable and must be mutated to resolve the field and
	* any related fields. This method will only be invoked during parsing
	* if the map contains this field, and implementations should therefore
	* assume this field is present.
	* <p>
	* Resolving a field will consist of looking at the value of this field,
	* and potentially other fields, and either updating the map with a
	* simpler value, such as a {@code ChronoField}, or returning a
	* complete {@code ChronoLocalDate}. If a resolve is successful,
	* the code must remove all the fields that were resolved from the map,
	* including this field.
	* <p>
	* For example, the {@code IsoFields} class contains the quarter-of-year
	* and day-of-quarter fields. The implementation of this method in that class
	* resolves the two fields plus the {@link ChronoField#YEAR YEAR} into a
	* complete {@code LocalDate}. The resolve method will remove all three
	* fields from the map before returning the {@code LocalDate}.
	* <p>
	* A partially complete temporal is used to allow the chronology and zone
	* to be queried. In general, only the chronology will be needed.
	* Querying items other than the zone or chronology is undefined and
	* must not be relied on.
	* The behavior of other methods such as {@code get}, {@code getLong},
	* {@code range} and {@code isSupported} is unpredictable and the results undefined.
	* <p>
	* If resolution should be possible, but the data is invalid, the resolver
	* style should be used to determine an appropriate level of leniency, which
	* may require throwing a {@code DateTimeException} or {@code ArithmeticException}.
	* If no resolution is possible, the resolve method must return null.
	* <p>
	* When resolving time fields, the map will be altered and null returned.
	* When resolving date fields, the date is normally returned from the method,
	* with the map altered to remove the resolved fields. However, it would also
	* be acceptable for the date fields to be resolved into other {@code ChronoField}
	* instances that can produce a date, such as {@code EPOCH_DAY}.
	* <p>
	* Not all {@code TemporalAccessor} implementations are accepted as return values.
	* Implementations that call this method must accept {@code ChronoLocalDate},
	* {@code ChronoLocalDateTime}, {@code ChronoZonedDateTime} and {@code LocalTime}.
	* <p>
	* The default implementation must return null.
	*
	* @param fieldValues the map of fields to values, which can be updated, not null
	* @param partialTemporal the partially complete temporal to query for zone and
	* chronology; querying for other things is undefined and not recommended, not null
	* @param resolverStyle the requested type of resolve, not null
	* @return the resolved temporal object; null if resolving only
	* changed the map, or no resolve occurred
	* @throws ArithmeticException if numeric overflow occurs
	* @throws DateTimeException if resolving results in an error. This must not be thrown
	* by querying a field on the temporal without first checking if it is supported
	*/
	default TemporalAccessor resolve(
	Map<TemporalField, Long> fieldValues,
	TemporalAccessor partialTemporal,
	ResolverStyle resolverStyle) {
	return null;
	}

	/**
	* Gets a descriptive name for the field.
	* <p>
	* The should be of the format 'BaseOfRange', such as 'MonthOfYear',
	* unless the field has a range of {@code FOREVER}, when only
	* the base unit is mentioned, such as 'Year' or 'Era'.
	*
	* @return the name of the field, not null
	*/
	@Override
	String toString();


	}

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