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 * Copyright (c) 2012, 2019, 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,

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 *

 * 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) 2008-2012, Stephen Colebourne & Michael Nascimento Santos

 *

 * All rights hg qreserved.

 *

 * 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.format;

import static java.time.temporal.ChronoField.DAY_OF_MONTH;

import static java.time.temporal.ChronoField.HOUR_OF_DAY;

import static java.time.temporal.ChronoField.INSTANT_SECONDS;

import static java.time.temporal.ChronoField.MINUTE_OF_HOUR;

import static java.time.temporal.ChronoField.MONTH_OF_YEAR;

import static java.time.temporal.ChronoField.NANO_OF_SECOND;

import static java.time.temporal.ChronoField.OFFSET_SECONDS;

import static java.time.temporal.ChronoField.SECOND_OF_MINUTE;

import static java.time.temporal.ChronoField.YEAR;

import java.lang.ref.SoftReference;

import java.math.BigDecimal;

import java.math.BigInteger;

import java.math.RoundingMode;

import java.text.ParsePosition;

import java.time.DateTimeException;

import java.time.Instant;

import java.time.LocalDate;

import java.time.LocalDateTime;

import java.time.ZoneId;

import java.time.ZoneOffset;

import java.time.chrono.ChronoLocalDate;

import java.time.chrono.Chronology;

import java.time.chrono.IsoChronology;

import java.time.format.DateTimeTextProvider.LocaleStore;

import java.time.temporal.ChronoField;

import java.time.temporal.IsoFields;

import java.time.temporal.TemporalAccessor;

import java.time.temporal.TemporalField;

import java.time.temporal.TemporalQueries;

import java.time.temporal.TemporalQuery;

import java.time.temporal.ValueRange;

import java.time.temporal.WeekFields;

import java.time.zone.ZoneRulesProvider;

import java.util.AbstractMap.SimpleImmutableEntry;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collections;

import java.util.Comparator;

import java.util.HashMap;

import java.util.HashSet;

import java.util.Iterator;

import java.util.LinkedHashMap;

import java.util.List;

import java.util.Locale;

import java.util.Map;

import java.util.Map.Entry;

import java.util.Objects;

import java.util.Set;

import java.util.TimeZone;

import java.util.concurrent.ConcurrentHashMap;

import java.util.concurrent.ConcurrentMap;

import sun.util.locale.provider.LocaleProviderAdapter;

import sun.util.locale.provider.LocaleResources;

import sun.util.locale.provider.TimeZoneNameUtility;

/**

 * Builder to create date-time formatters.

 * <p>

 * This allows a {@code DateTimeFormatter} to be created.

 * All date-time formatters are created ultimately using this builder.

 * <p>

 * The basic elements of date-time can all be added:

 * <ul>

 * <li>Value - a numeric value</li>

 * <li>Fraction - a fractional value including the decimal place. Always use this when

 * outputting fractions to ensure that the fraction is parsed correctly</li>

 * <li>Text - the textual equivalent for the value</li>

 * <li>OffsetId/Offset - the {@linkplain ZoneOffset zone offset}</li>

 * <li>ZoneId - the {@linkplain ZoneId time-zone} id</li>

 * <li>ZoneText - the name of the time-zone</li>

 * <li>ChronologyId - the {@linkplain Chronology chronology} id</li>

 * <li>ChronologyText - the name of the chronology</li>

 * <li>Literal - a text literal</li>

 * <li>Nested and Optional - formats can be nested or made optional</li>

 * </ul>

 * In addition, any of the elements may be decorated by padding, either with spaces or any other character.

 * <p>

 * Finally, a shorthand pattern, mostly compatible with {@code java.text.SimpleDateFormat SimpleDateFormat}

 * can be used, see {@link #appendPattern(String)}.

 * In practice, this simply parses the pattern and calls other methods on the builder.

 *

 * @implSpec

 * This class is a mutable builder intended for use from a single thread.

 *

 * @since 1.8

 */

public final class DateTimeFormatterBuilder {

    /**

     * Query for a time-zone that is region-only.

     */

    private static final TemporalQuery<ZoneId> QUERY_REGION_ONLY = (temporal) -> {

        ZoneId zone = temporal.query(TemporalQueries.zoneId());

        return (zone != null && zone instanceof ZoneOffset == false ? zone : null);

    };

    /**

     * The currently active builder, used by the outermost builder.

     */

    private DateTimeFormatterBuilder active = this;

    /**

     * The parent builder, null for the outermost builder.

     */

    private final DateTimeFormatterBuilder parent;

    /**

     * The list of printers that will be used.

     */

    private final List<DateTimePrinterParser> printerParsers = new ArrayList<>();

    /**

     * Whether this builder produces an optional formatter.

     */

    private final boolean optional;

    /**

     * The width to pad the next field to.

     */

    private int padNextWidth;

    /**

     * The character to pad the next field with.

     */

    private char padNextChar;

    /**

     * The index of the last variable width value parser.

     */

    private int valueParserIndex = -1;

    /**

     * Gets the formatting pattern for date and time styles for a locale and chronology.

     * The locale and chronology are used to lookup the locale specific format

     * for the requested dateStyle and/or timeStyle.

     *

     * @param dateStyle  the FormatStyle for the date, null for time-only pattern

     * @param timeStyle  the FormatStyle for the time, null for date-only pattern

     * @param chrono  the Chronology, non-null

     * @param locale  the locale, non-null

     * @return the locale and Chronology specific formatting pattern

     * @throws IllegalArgumentException if both dateStyle and timeStyle are null

     */

    public static String getLocalizedDateTimePattern(FormatStyle dateStyle, FormatStyle timeStyle,

            Chronology chrono, Locale locale) {

        Objects.requireNonNull(locale, "locale");

        Objects.requireNonNull(chrono, "chrono");

        if (dateStyle == null && timeStyle == null) {

            throw new IllegalArgumentException("Either dateStyle or timeStyle must be non-null");

        }

        LocaleResources lr = LocaleProviderAdapter.getResourceBundleBased().getLocaleResources(locale);

        String pattern = lr.getJavaTimeDateTimePattern(

                convertStyle(timeStyle), convertStyle(dateStyle), chrono.getCalendarType());

        return pattern;

    }

    /**

     * Converts the given FormatStyle to the java.text.DateFormat style.

     *

     * @param style  the FormatStyle style

     * @return the int style, or -1 if style is null, indicating un-required

     */

    private static int convertStyle(FormatStyle style) {

        if (style == null) {

            return -1;

        }

        return style.ordinal();  // indices happen to align

    }

    /**

     * Constructs a new instance of the builder.

     */

    public DateTimeFormatterBuilder() {

        super();

        parent = null;

        optional = false;

    }

    /**

     * Constructs a new instance of the builder.

     *

     * @param parent  the parent builder, not null

     * @param optional  whether the formatter is optional, not null

     */

    private DateTimeFormatterBuilder(DateTimeFormatterBuilder parent, boolean optional) {

        super();

        this.parent = parent;

        this.optional = optional;

    }

    //-----------------------------------------------------------------------

    /**

     * Changes the parse style to be case sensitive for the remainder of the formatter.

     * <p>

     * Parsing can be case sensitive or insensitive - by default it is case sensitive.

     * This method allows the case sensitivity setting of parsing to be changed.

     * <p>

     * Calling this method changes the state of the builder such that all

     * subsequent builder method calls will parse text in case sensitive mode.

     * See {@link #parseCaseInsensitive} for the opposite setting.

     * The parse case sensitive/insensitive methods may be called at any point

     * in the builder, thus the parser can swap between case parsing modes

     * multiple times during the parse.

     * <p>

     * Since the default is case sensitive, this method should only be used after

     * a previous call to {@code #parseCaseInsensitive}.

     *

     * @return this, for chaining, not null

     */

    public DateTimeFormatterBuilder parseCaseSensitive() {

        appendInternal(SettingsParser.SENSITIVE);

        return this;

    }

    /**

     * Changes the parse style to be case insensitive for the remainder of the formatter.

     * <p>

     * Parsing can be case sensitive or insensitive - by default it is case sensitive.

     * This method allows the case sensitivity setting of parsing to be changed.

     * <p>

     * Calling this method changes the state of the builder such that all

     * subsequent builder method calls will parse text in case insensitive mode.

     * See {@link #parseCaseSensitive()} for the opposite setting.

     * The parse case sensitive/insensitive methods may be called at any point

     * in the builder, thus the parser can swap between case parsing modes

     * multiple times during the parse.

     *

     * @return this, for chaining, not null

     */

    public DateTimeFormatterBuilder parseCaseInsensitive() {

        appendInternal(SettingsParser.INSENSITIVE);

        return this;

    }

    //-----------------------------------------------------------------------

    /**

     * Changes the parse style to be strict for the remainder of the formatter.

     * <p>

     * Parsing can be strict or lenient - by default its strict.

     * This controls the degree of flexibility in matching the text and sign styles.

     * <p>

     * When used, this method changes the parsing to be strict from this point onwards.

     * As strict is the default, this is normally only needed after calling {@link #parseLenient()}.

     * The change will remain in force until the end of the formatter that is eventually

     * constructed or until {@code parseLenient} is called.

     *

     * @return this, for chaining, not null

     */

    public DateTimeFormatterBuilder parseStrict() {

        appendInternal(SettingsParser.STRICT);

        return this;

    }

    /**

     * Changes the parse style to be lenient for the remainder of the formatter.

     * Note that case sensitivity is set separately to this method.

     * <p>

     * Parsing can be strict or lenient - by default its strict.

     * This controls the degree of flexibility in matching the text and sign styles.

     * Applications calling this method should typically also call {@link #parseCaseInsensitive()}.

     * <p>

     * When used, this method changes the parsing to be lenient from this point onwards.

     * The change will remain in force until the end of the formatter that is eventually

     * constructed or until {@code parseStrict} is called.

     *

     * @return this, for chaining, not null

     */

    public DateTimeFormatterBuilder parseLenient() {

        appendInternal(SettingsParser.LENIENT);

        return this;

    }

    //-----------------------------------------------------------------------

    /**

     * Appends a default value for a field to the formatter for use in parsing.

     * <p>

     * This appends an instruction to the builder to inject a default value

     * into the parsed result. This is especially useful in conjunction with

     * optional parts of the formatter.

     * <p>

     * For example, consider a formatter that parses the year, followed by

     * an optional month, with a further optional day-of-month. Using such a

     * formatter would require the calling code to check whether a full date,

     * year-month or just a year had been parsed. This method can be used to

     * default the month and day-of-month to a sensible value, such as the

     * first of the month, allowing the calling code to always get a date.

     * <p>

     * During formatting, this method has no effect.

     * <p>

     * During parsing, the current state of the parse is inspected.

     * If the specified field has no associated value, because it has not been

     * parsed successfully at that point, then the specified value is injected

     * into the parse result. Injection is immediate, thus the field-value pair

     * will be visible to any subsequent elements in the formatter.

     * As such, this method is normally called at the end of the builder.

     *

     * @param field  the field to default the value of, not null

     * @param value  the value to default the field to

     * @return this, for chaining, not null

     */

    public DateTimeFormatterBuilder parseDefaulting(TemporalField field, long value) {

        Objects.requireNonNull(field, "field");

        appendInternal(new DefaultValueParser(field, value));

        return this;

    }

    //-----------------------------------------------------------------------

    /**

     * Appends the value of a date-time field to the formatter using a normal

     * output style.

     * <p>

     * The value of the field will be output during a format.

     * If the value cannot be obtained then an exception will be thrown.

     * <p>

     * The value will be printed as per the normal format of an integer value.

     * Only negative numbers will be signed. No padding will be added.

     * <p>

     * The parser for a variable width value such as this normally behaves greedily,

     * requiring one digit, but accepting as many digits as possible.

     * This behavior can be affected by 'adjacent value parsing'.

     * See {@link #appendValue(java.time.temporal.TemporalField, int)} for full details.

     *

     * @param field  the field to append, not null

     * @return this, for chaining, not null

     */

    public DateTimeFormatterBuilder appendValue(TemporalField field) {

        Objects.requireNonNull(field, "field");

        appendValue(new NumberPrinterParser(field, 1, 19, SignStyle.NORMAL));

        return this;

    }

    /**

     * Appends the value of a date-time field to the formatter using a fixed

     * width, zero-padded approach.

     * <p>

     * The value of the field will be output during a format.

     * If the value cannot be obtained then an exception will be thrown.

     * <p>

     * The value will be zero-padded on the left. If the size of the value

     * means that it cannot be printed within the width then an exception is thrown.

     * If the value of the field is negative then an exception is thrown during formatting.

     * <p>

     * This method supports a special technique of parsing known as 'adjacent value parsing'.

     * This technique solves the problem where a value, variable or fixed width, is followed by one or more

     * fixed length values. The standard parser is greedy, and thus it would normally

     * steal the digits that are needed by the fixed width value parsers that follow the

     * variable width one.

     * <p>

     * No action is required to initiate 'adjacent value parsing'.

     * When a call to {@code appendValue} is made, the builder

     * enters adjacent value parsing setup mode. If the immediately subsequent method

     * call or calls on the same builder are for a fixed width value, then the parser will reserve

     * space so that the fixed width values can be parsed.

     * <p>

     * For example, consider {@code builder.appendValue(YEAR).appendValue(MONTH_OF_YEAR, 2);}

     * The year is a variable width parse of between 1 and 19 digits.

     * The month is a fixed width parse of 2 digits.

     * Because these were appended to the same builder immediately after one another,

     * the year parser will reserve two digits for the month to parse.

     * Thus, the text '201106' will correctly parse to a year of 2011 and a month of 6.

     * Without adjacent value parsing, the year would greedily parse all six digits and leave

     * nothing for the month.

     * <p>

     * Adjacent value parsing applies to each set of fixed width not-negative values in the parser

     * that immediately follow any kind of value, variable or fixed width.

     * Calling any other append method will end the setup of adjacent value parsing.

     * Thus, in the unlikely event that you need to avoid adjacent value parsing behavior,

     * simply add the {@code appendValue} to another {@code DateTimeFormatterBuilder}

     * and add that to this builder.

     * <p>

     * If adjacent parsing is active, then parsing must match exactly the specified

     * number of digits in both strict and lenient modes.

     * In addition, no positive or negative sign is permitted.

     *

     * @param field  the field to append, not null

     * @param width  the width of the printed field, from 1 to 19

     * @return this, for chaining, not null

     * @throws IllegalArgumentException if the width is invalid

     */

    public DateTimeFormatterBuilder appendValue(TemporalField field, int width) {

        Objects.requireNonNull(field, "field");

        if (width < 1 || width > 19) {

            throw new IllegalArgumentException("The width must be from 1 to 19 inclusive but was " + width);

        }

        NumberPrinterParser pp = new NumberPrinterParser(field, width, width, SignStyle.NOT_NEGATIVE);

        appendValue(pp);

        return this;

    }

    /**

     * Appends the value of a date-time field to the formatter providing full

     * control over formatting.

     * <p>

     * The value of the field will be output during a format.

     * If the value cannot be obtained then an exception will be thrown.

     * <p>

     * This method provides full control of the numeric formatting, including

     * zero-padding and the positive/negative sign.

     * <p>

     * The parser for a variable width value such as this normally behaves greedily,

     * accepting as many digits as possible.

     * This behavior can be affected by 'adjacent value parsing'.

     * See {@link #appendValue(java.time.temporal.TemporalField, int)} for full details.

     * <p>

     * In strict parsing mode, the minimum number of parsed digits is {@code minWidth}

     * and the maximum is {@code maxWidth}.

     * In lenient parsing mode, the minimum number of parsed digits is one

     * and the maximum is 19 (except as limited by adjacent value parsing).

     * <p>

     * If this method is invoked with equal minimum and maximum widths and a sign style of

     * {@code NOT_NEGATIVE} then it delegates to {@code appendValue(TemporalField,int)}.

     * In this scenario, the formatting and parsing behavior described there occur.

     *

     * @param field  the field to append, not null

     * @param minWidth  the minimum field width of the printed field, from 1 to 19

     * @param maxWidth  the maximum field width of the printed field, from 1 to 19

     * @param signStyle  the positive/negative output style, not null

     * @return this, for chaining, not null

     * @throws IllegalArgumentException if the widths are invalid

     */

    public DateTimeFormatterBuilder appendValue(

            TemporalField field, int minWidth, int maxWidth, SignStyle signStyle) {

        if (minWidth == maxWidth && signStyle == SignStyle.NOT_NEGATIVE) {

            return appendValue(field, maxWidth);

        }

        Objects.requireNonNull(field, "field");

        Objects.requireNonNull(signStyle, "signStyle");

        if (minWidth < 1 || minWidth > 19) {

            throw new IllegalArgumentException("The minimum width must be from 1 to 19 inclusive but was " + minWidth);

        }

        if (maxWidth < 1 || maxWidth > 19) {

            throw new IllegalArgumentException("The maximum width must be from 1 to 19 inclusive but was " + maxWidth);

        }

        if (maxWidth < minWidth) {

            throw new IllegalArgumentException("The maximum width must exceed or equal the minimum width but " +

                    maxWidth + " < " + minWidth);

        }

        NumberPrinterParser pp = new NumberPrinterParser(field, minWidth, maxWidth, signStyle);

        appendValue(pp);

        return this;

    }

    //-----------------------------------------------------------------------

    /**

     * Appends the reduced value of a date-time field to the formatter.

     * <p>

     * Since fields such as year vary by chronology, it is recommended to use the

     * {@link #appendValueReduced(TemporalField, int, int, ChronoLocalDate)} date}

     * variant of this method in most cases. This variant is suitable for

     * simple fields or working with only the ISO chronology.

     * <p>

     * For formatting, the {@code width} and {@code maxWidth} are used to

     * determine the number of characters to format.

     * If they are equal then the format is fixed width.

     * If the value of the field is within the range of the {@code baseValue} using

     * {@code width} characters then the reduced value is formatted otherwise the value is

     * truncated to fit {@code maxWidth}.

     * The rightmost characters are output to match the width, left padding with zero.

     * <p>

     * For strict parsing, the number of characters allowed by {@code width} to {@code maxWidth} are parsed.

     * For lenient parsing, the number of characters must be at least 1 and less than 10.

     * If the number of digits parsed is equal to {@code width} and the value is positive,

     * the value of the field is computed to be the first number greater than

     * or equal to the {@code baseValue} with the same least significant characters,

     * otherwise the value parsed is the field value.

     * This allows a reduced value to be entered for values in range of the baseValue

     * and width and absolute values can be entered for values outside the range.

     * <p>

     * For example, a base value of {@code 1980} and a width of {@code 2} will have

     * valid values from {@code 1980} to {@code 2079}.

     * During parsing, the text {@code "12"} will result in the value {@code 2012} as that

     * is the value within the range where the last two characters are "12".

     * By contrast, parsing the text {@code "1915"} will result in the value {@code 1915}.

     *

     * @param field  the field to append, not null

     * @param width  the field width of the printed and parsed field, from 1 to 10

     * @param maxWidth  the maximum field width of the printed field, from 1 to 10

     * @param baseValue  the base value of the range of valid values

     * @return this, for chaining, not null

     * @throws IllegalArgumentException if the width or base value is invalid

     */

    public DateTimeFormatterBuilder appendValueReduced(TemporalField field,

            int width, int maxWidth, int baseValue) {

        Objects.requireNonNull(field, "field");

        ReducedPrinterParser pp = new ReducedPrinterParser(field, width, maxWidth, baseValue, null);

        appendValue(pp);

        return this;

    }

    /**

     * Appends the reduced value of a date-time field to the formatter.

     * <p>

     * This is typically used for formatting and parsing a two digit year.

     * <p>

     * The base date is used to calculate the full value during parsing.

     * For example, if the base date is 1950-01-01 then parsed values for

     * a two digit year parse will be in the range 1950-01-01 to 2049-12-31.

     * Only the year would be extracted from the date, thus a base date of

     * 1950-08-25 would also parse to the range 1950-01-01 to 2049-12-31.

     * This behavior is necessary to support fields such as week-based-year

     * or other calendar systems where the parsed value does not align with

     * standard ISO years.

     * <p>

     * The exact behavior is as follows. Parse the full set of fields and

     * determine the effective chronology using the last chronology if

     * it appears more than once. Then convert the base date to the

     * effective chronology. Then extract the specified field from the

     * chronology-specific base date and use it to determine the

     * {@code baseValue} used below.

     * <p>

     * For formatting, the {@code width} and {@code maxWidth} are used to

     * determine the number of characters to format.

     * If they are equal then the format is fixed width.

     * If the value of the field is within the range of the {@code baseValue} using

     * {@code width} characters then the reduced value is formatted otherwise the value is

     * truncated to fit {@code maxWidth}.

     * The rightmost characters are output to match the width, left padding with zero.

     * <p>

     * For strict parsing, the number of characters allowed by {@code width} to {@code maxWidth} are parsed.

     * For lenient parsing, the number of characters must be at least 1 and less than 10.

     * If the number of digits parsed is equal to {@code width} and the value is positive,

     * the value of the field is computed to be the first number greater than

     * or equal to the {@code baseValue} with the same least significant characters,

     * otherwise the value parsed is the field value.

     * This allows a reduced value to be entered for values in range of the baseValue

     * and width and absolute values can be entered for values outside the range.

     * <p>

     * For example, a base value of {@code 1980} and a width of {@code 2} will have

     * valid values from {@code 1980} to {@code 2079}.

     * During parsing, the text {@code "12"} will result in the value {@code 2012} as that

     * is the value within the range where the last two characters are "12".

     * By contrast, parsing the text {@code "1915"} will result in the value {@code 1915}.

     *

     * @param field  the field to append, not null

     * @param width  the field width of the printed and parsed field, from 1 to 10

     * @param maxWidth  the maximum field width of the printed field, from 1 to 10

     * @param baseDate  the base date used to calculate the base value for the range

     *  of valid values in the parsed chronology, not null

     * @return this, for chaining, not null

     * @throws IllegalArgumentException if the width or base value is invalid

     */

    public DateTimeFormatterBuilder appendValueReduced(

            TemporalField field, int width, int maxWidth, ChronoLocalDate baseDate) {

        Objects.requireNonNull(field, "field");

        Objects.requireNonNull(baseDate, "baseDate");

        ReducedPrinterParser pp = new ReducedPrinterParser(field, width, maxWidth, 0, baseDate);

        appendValue(pp);

        return this;

    }

    /**

     * Appends a fixed or variable width printer-parser handling adjacent value mode.

     * If a PrinterParser is not active then the new PrinterParser becomes

     * the active PrinterParser.

     * Otherwise, the active PrinterParser is modified depending on the new PrinterParser.

     * If the new PrinterParser is fixed width and has sign style {@code NOT_NEGATIVE}

     * then its width is added to the active PP and

     * the new PrinterParser is forced to be fixed width.

     * If the new PrinterParser is variable width, the active PrinterParser is changed

     * to be fixed width and the new PrinterParser becomes the active PP.

     *

     * @param pp  the printer-parser, not null

     * @return this, for chaining, not null

     */

    private DateTimeFormatterBuilder appendValue(NumberPrinterParser pp) {

        if (active.valueParserIndex >= 0) {

            final int activeValueParser = active.valueParserIndex;

            // adjacent parsing mode, update setting in previous parsers

            NumberPrinterParser basePP = (NumberPrinterParser) active.printerParsers.get(activeValueParser);

            if (pp.minWidth == pp.maxWidth && pp.signStyle == SignStyle.NOT_NEGATIVE) {

                // Append the width to the subsequentWidth of the active parser

                basePP = basePP.withSubsequentWidth(pp.maxWidth);

                // Append the new parser as a fixed width

                appendInternal(pp.withFixedWidth());

                // Retain the previous active parser

                active.valueParserIndex = activeValueParser;

            } else {

                // Modify the active parser to be fixed width

                basePP = basePP.withFixedWidth();

                // The new parser becomes the mew active parser

                active.valueParserIndex = appendInternal(pp);

            }

            // Replace the modified parser with the updated one

            active.printerParsers.set(activeValueParser, basePP);

        } else {

            // The new Parser becomes the active parser

            active.valueParserIndex = appendInternal(pp);

        }

        return this;

    }

    //-----------------------------------------------------------------------

    /**

     * Appends the fractional value of a date-time field to the formatter.

     * <p>

     * The fractional value of the field will be output including the

     * preceding decimal point. The preceding value is not output.

     * For example, the second-of-minute value of 15 would be output as {@code .25}.

     * <p>

     * The width of the printed fraction can be controlled. Setting the

     * minimum width to zero will cause no output to be generated.

     * The printed fraction will have the minimum width necessary between

     * the minimum and maximum widths - trailing zeroes are omitted.

     * No rounding occurs due to the maximum width - digits are simply dropped.

     * <p>

     * When parsing in strict mode, the number of parsed digits must be between

     * the minimum and maximum width. When parsing in lenient mode, the minimum

     * width is considered to be zero and the maximum is nine.

     * <p>

     * If the value cannot be obtained then an exception will be thrown.

     * If the value is negative an exception will be thrown.

     * If the field does not have a fixed set of valid values then an

     * exception will be thrown.

     * If the field value in the date-time to be printed is invalid it

     * cannot be printed and an exception will be thrown.

     *

     * @param field  the field to append, not null

     * @param minWidth  the minimum width of the field excluding the decimal point, from 0 to 9

     * @param maxWidth  the maximum width of the field excluding the decimal point, from 1 to 9

     * @param decimalPoint  whether to output the localized decimal point symbol

     * @return this, for chaining, not null

     * @throws IllegalArgumentException if the field has a variable set of valid values or

     *  either width is invalid

     */

    public DateTimeFormatterBuilder appendFraction(

            TemporalField field, int minWidth, int maxWidth, boolean decimalPoint) {

        appendInternal(new FractionPrinterParser(field, minWidth, maxWidth, decimalPoint));

        return this;

    }

    //-----------------------------------------------------------------------

    /**

     * Appends the text of a date-time field to the formatter using the full

     * text style.

     * <p>

     * The text of the field will be output during a format.

     * The value must be within the valid range of the field.

     * If the value cannot be obtained then an exception will be thrown.

     * If the field has no textual representation, then the numeric value will be used.

     * <p>

     * The value will be printed as per the normal format of an integer value.

     * Only negative numbers will be signed. No padding will be added.

     *

     * @param field  the field to append, not null

     * @return this, for chaining, not null

     */

    public DateTimeFormatterBuilder appendText(TemporalField field) {

        return appendText(field, TextStyle.FULL);

    }

    /**

     * Appends the text of a date-time field to the formatter.

     * <p>

     * The text of the field will be output during a format.

     * The value must be within the valid range of the field.

     * If the value cannot be obtained then an exception will be thrown.

     * If the field has no textual representation, then the numeric value will be used.

     * <p>

     * The value will be printed as per the normal format of an integer value.

     * Only negative numbers will be signed. No padding will be added.

     *

     * @param field  the field to append, not null

     * @param textStyle  the text style to use, not null

     * @return this, for chaining, not null

     */

    public DateTimeFormatterBuilder appendText(TemporalField field, TextStyle textStyle) {

        Objects.requireNonNull(field, "field");

        Objects.requireNonNull(textStyle, "textStyle");

        appendInternal(new TextPrinterParser(field, textStyle, DateTimeTextProvider.getInstance()));

        return this;

    }

    /**

     * Appends the text of a date-time field to the formatter using the specified

     * map to supply the text.

     * <p>

     * The standard text outputting methods use the localized text in the JDK.

     * This method allows that text to be specified directly.

     * The supplied map is not validated by the builder to ensure that formatting or

     * parsing is possible, thus an invalid map may throw an error during later use.

     * <p>

     * Supplying the map of text provides considerable flexibility in formatting and parsing.

     * For example, a legacy application might require or supply the months of the

     * year as "JNY", "FBY", "MCH" etc. These do not match the standard set of text

     * for localized month names. Using this method, a map can be created which

     * defines the connection between each value and the text:

     * <pre>

     * Map<Long, String> map = new HashMap<>();

     * map.put(1L, "JNY");

     * map.put(2L, "FBY");

     * map.put(3L, "MCH");

     * ...

     * builder.appendText(MONTH_OF_YEAR, map);

     * </pre>

     * <p>

     * Other uses might be to output the value with a suffix, such as "1st", "2nd", "3rd",

     * or as Roman numerals "I", "II", "III", "IV".

     * <p>

     * During formatting, the value is obtained and checked that it is in the valid range.

     * If text is not available for the value then it is output as a number.

     * During parsing, the parser will match against the map of text and numeric values.

     *

     * @param field  the field to append, not null

     * @param textLookup  the map from the value to the text

     * @return this, for chaining, not null

     */

    public DateTimeFormatterBuilder appendText(TemporalField field, Map<Long, String> textLookup) {

        Objects.requireNonNull(field, "field");

        Objects.requireNonNull(textLookup, "textLookup");

        Map<Long, String> copy = new LinkedHashMap<>(textLookup);

        Map<TextStyle, Map<Long, String>> map = Collections.singletonMap(TextStyle.FULL, copy);

        final LocaleStore store = new LocaleStore(map);

        DateTimeTextProvider provider = new DateTimeTextProvider() {

            @Override

            public String getText(Chronology chrono, TemporalField field,

                                  long value, TextStyle style, Locale locale) {

                return store.getText(value, style);

            }

            @Override

            public String getText(TemporalField field, long value, TextStyle style, Locale locale) {

                return store.getText(value, style);

            }

            @Override

            public Iterator<Entry<String, Long>> getTextIterator(Chronology chrono,

                    TemporalField field, TextStyle style, Locale locale) {

                return store.getTextIterator(style);

            }

            @Override

            public Iterator<Entry<String, Long>> getTextIterator(TemporalField field,

                    TextStyle style, Locale locale) {

                return store.getTextIterator(style);

            }

        };

        appendInternal(new TextPrinterParser(field, TextStyle.FULL, provider));

        return this;

    }

    //-----------------------------------------------------------------------

    /**

     * Appends an instant using ISO-8601 to the formatter, formatting fractional

     * digits in groups of three.

     * <p>

     * Instants have a fixed output format.

     * They are converted to a date-time with a zone-offset of UTC and formatted

     * using the standard ISO-8601 format.

     * With this method, formatting nano-of-second outputs zero, three, six

     * or nine digits digits as necessary.

     * The localized decimal style is not used.

     * <p>

     * The instant is obtained using {@link ChronoField#INSTANT_SECONDS INSTANT_SECONDS}

     * and optionally (@code NANO_OF_SECOND). The value of {@code INSTANT_SECONDS}

     * may be outside the maximum range of {@code LocalDateTime}.

     * <p>

     * The {@linkplain ResolverStyle resolver style} has no effect on instant parsing.

     * The end-of-day time of '24:00' is handled as midnight at the start of the following day.

     * The leap-second time of '23:59:59' is handled to some degree, see

     * {@link DateTimeFormatter#parsedLeapSecond()} for full details.

     * <p>

     * An alternative to this method is to format/parse the instant as a single

     * epoch-seconds value. That is achieved using {@code appendValue(INSTANT_SECONDS)}.

     *

     * @return this, for chaining, not null

     */

    public DateTimeFormatterBuilder appendInstant() {

        appendInternal(new InstantPrinterParser(-2));

        return this;

    }

    /**

     * Appends an instant using ISO-8601 to the formatter with control over

     * the number of fractional digits.

     * <p>

     * Instants have a fixed output format, although this method provides some

     * control over the fractional digits. They are converted to a date-time

     * with a zone-offset of UTC and printed using the standard ISO-8601 format.

     * The localized decimal style is not used.

     * <p>

     * The {@code fractionalDigits} parameter allows the output of the fractional

     * second to be controlled. Specifying zero will cause no fractional digits

     * to be output. From 1 to 9 will output an increasing number of digits, using

     * zero right-padding if necessary. The special value -1 is used to output as

     * many digits as necessary to avoid any trailing zeroes.

     * <p>

     * When parsing in strict mode, the number of parsed digits must match the

     * fractional digits. When parsing in lenient mode, any number of fractional

     * digits from zero to nine are accepted.

     * <p>

     * The instant is obtained using {@link ChronoField#INSTANT_SECONDS INSTANT_SECONDS}

     * and optionally (@code NANO_OF_SECOND). The value of {@code INSTANT_SECONDS}

     * may be outside the maximum range of {@code LocalDateTime}.

     * <p>

     * The {@linkplain ResolverStyle resolver style} has no effect on instant parsing.

     * The end-of-day time of '24:00' is handled as midnight at the start of the following day.

     * The leap-second time of '23:59:60' is handled to some degree, see

     * {@link DateTimeFormatter#parsedLeapSecond()} for full details.

     * <p>

     * An alternative to this method is to format/parse the instant as a single

     * epoch-seconds value. That is achieved using {@code appendValue(INSTANT_SECONDS)}.

     *

     * @param fractionalDigits  the number of fractional second digits to format with,

     *  from 0 to 9, or -1 to use as many digits as necessary

     * @return this, for chaining, not null

     */

    public DateTimeFormatterBuilder appendInstant(int fractionalDigits) {

        if (fractionalDigits < -1 || fractionalDigits > 9) {

            throw new IllegalArgumentException("The fractional digits must be from -1 to 9 inclusive but was " + fractionalDigits);

        }

        appendInternal(new InstantPrinterParser(fractionalDigits));

        return this;

    }

    //-----------------------------------------------------------------------

    /**

     * Appends the zone offset, such as '+01:00', to the formatter.

     * <p>

     * This appends an instruction to format/parse the offset ID to the builder.

     * This is equivalent to calling {@code appendOffset("+HH:MM:ss", "Z")}.

     *

     * @return this, for chaining, not null

     */

    public DateTimeFormatterBuilder appendOffsetId() {

        appendInternal(OffsetIdPrinterParser.INSTANCE_ID_Z);

        return this;

    }

    /**

     * Appends the zone offset, such as '+01:00', to the formatter.

     * <p>

     * This appends an instruction to format/parse the offset ID to the builder.

     * <p>

     * During formatting, the offset is obtained using a mechanism equivalent

     * to querying the temporal with {@link TemporalQueries#offset()}.

     * It will be printed using the format defined below.

     * If the offset cannot be obtained then an exception is thrown unless the

     * section of the formatter is optional.

     * <p>

     * During parsing, the offset is parsed using the format defined below.

     * If the offset cannot be parsed then an exception is thrown unless the

     * section of the formatter is optional.

     * <p>

     * The format of the offset is controlled by a pattern which must be one

     * of the following:

     * <ul>

     * <li>{@code +HH} - hour only, ignoring minute and second

     * <li>{@code +HHmm} - hour, with minute if non-zero, ignoring second, no colon

     * <li>{@code +HH:mm} - hour, with minute if non-zero, ignoring second, with colon

     * <li>{@code +HHMM} - hour and minute, ignoring second, no colon

     * <li>{@code +HH:MM} - hour and minute, ignoring second, with colon

     * <li>{@code +HHMMss} - hour and minute, with second if non-zero, no colon

     * <li>{@code +HH:MM:ss} - hour and minute, with second if non-zero, with colon

     * <li>{@code +HHMMSS} - hour, minute and second, no colon

     * <li>{@code +HH:MM:SS} - hour, minute and second, with colon

     * </ul>

     * The "no offset" text controls what text is printed when the total amount of

     * the offset fields to be output is zero.

     * Example values would be 'Z', '+00:00', 'UTC' or 'GMT'.

     * Three formats are accepted for parsing UTC - the "no offset" text, and the

     * plus and minus versions of zero defined by the pattern.

     *

     * @param pattern  the pattern to use, not null

     * @param noOffsetText  the text to use when the offset is zero, not null

     * @return this, for chaining, not null

     */

    public DateTimeFormatterBuilder appendOffset(String pattern, String noOffsetText) {

        appendInternal(new OffsetIdPrinterParser(pattern, noOffsetText));

        return this;

    }

    /**

     * Appends the localized zone offset, such as 'GMT+01:00', to the formatter.

     * <p>

     * This appends a localized zone offset to the builder, the format of the

     * localized offset is controlled by the specified {@link FormatStyle style}

     * to this method:

     * <ul>

     * <li>{@link TextStyle#FULL full} - formats with localized offset text, such

     * as 'GMT, 2-digit hour and minute field, optional second field if non-zero,

     * and colon.

     * <li>{@link TextStyle#SHORT short} - formats with localized offset text,

     * such as 'GMT, hour without leading zero, optional 2-digit minute and

     * second if non-zero, and colon.

     * </ul>

     * <p>

     * During formatting, the offset is obtained using a mechanism equivalent

     * to querying the temporal with {@link TemporalQueries#offset()}.

     * If the offset cannot be obtained then an exception is thrown unless the

     * section of the formatter is optional.

     * <p>

     * During parsing, the offset is parsed using the format defined above.

     * If the offset cannot be parsed then an exception is thrown unless the

     * section of the formatter is optional.

     * <p>

     * @param style  the format style to use, not null

     * @return this, for chaining, not null

     * @throws IllegalArgumentException if style is neither {@link TextStyle#FULL

     * full} nor {@link TextStyle#SHORT short}

     */

    public DateTimeFormatterBuilder appendLocalizedOffset(TextStyle style) {

        Objects.requireNonNull(style, "style");

        if (style != TextStyle.FULL && style != TextStyle.SHORT) {

            throw new IllegalArgumentException("Style must be either full or short");

        }

        appendInternal(new LocalizedOffsetIdPrinterParser(style));

        return this;

    }

    //-----------------------------------------------------------------------

    /**

     * Appends the time-zone ID, such as 'Europe/Paris' or '+02:00', to the formatter.

     * <p>

     * This appends an instruction to format/parse the zone ID to the builder.

     * The zone ID is obtained in a strict manner suitable for {@code ZonedDateTime}.

     * By contrast, {@code OffsetDateTime} does not have a zone ID suitable

     * for use with this method, see {@link #appendZoneOrOffsetId()}.

     * <p>

     * During formatting, the zone is obtained using a mechanism equivalent

     * to querying the temporal with {@link TemporalQueries#zoneId()}.

     * It will be printed using the result of {@link ZoneId#getId()}.

     * If the zone cannot be obtained then an exception is thrown unless the

     * section of the formatter is optional.

     * <p>

     * During parsing, the text must match a known zone or offset.

     * There are two types of zone ID, offset-based, such as '+01:30' and

     * region-based, such as 'Europe/London'. These are parsed differently.

     * If the parse starts with '+', '-', 'UT', 'UTC' or 'GMT', then the parser

     * expects an offset-based zone and will not match region-based zones.

     * The offset ID, such as '+02:30', may be at the start of the parse,

     * or prefixed by  'UT', 'UTC' or 'GMT'. The offset ID parsing is

     * equivalent to using {@link #appendOffset(String, String)} using the

     * arguments 'HH:MM:ss' and the no offset string '0'.

     * If the parse starts with 'UT', 'UTC' or 'GMT', and the parser cannot

     * match a following offset ID, then {@link ZoneOffset#UTC} is selected.

     * In all other cases, the list of known region-based zones is used to

     * find the longest available match. If no match is found, and the parse

     * starts with 'Z', then {@code ZoneOffset.UTC} is selected.

     * The parser uses the {@linkplain #parseCaseInsensitive() case sensitive} setting.

     * <p>

     * For example, the following will parse:

     * <pre>

     *   "Europe/London"           -- ZoneId.of("Europe/London")

     *   "Z"                       -- ZoneOffset.UTC

     *   "UT"                      -- ZoneId.of("UT")

     *   "UTC"                     -- ZoneId.of("UTC")

     *   "GMT"                     -- ZoneId.of("GMT")

     *   "+01:30"                  -- ZoneOffset.of("+01:30")

     *   "UT+01:30"                -- ZoneOffset.of("+01:30")

     *   "UTC+01:30"               -- ZoneOffset.of("+01:30")

     *   "GMT+01:30"               -- ZoneOffset.of("+01:30")

     * </pre>

     *

     * @return this, for chaining, not null

     * @see #appendZoneRegionId()

     */

    public DateTimeFormatterBuilder appendZoneId() {

        appendInternal(new ZoneIdPrinterParser(TemporalQueries.zoneId(), "ZoneId()"));

        return this;

    }

    /**

     * Appends the time-zone region ID, such as 'Europe/Paris', to the formatter,

     * rejecting the zone ID if it is a {@code ZoneOffset}.

     * <p>

     * This appends an instruction to format/parse the zone ID to the builder

     * only if it is a region-based ID.

     * <p>

     * During formatting, the zone is obtained using a mechanism equivalent

     * to querying the temporal with {@link TemporalQueries#zoneId()}.

     * If the zone is a {@code ZoneOffset} or it cannot be obtained then

     * an exception is thrown unless the section of the formatter is optional.

     * If the zone is not an offset, then the zone will be printed using

     * the zone ID from {@link ZoneId#getId()}.

     * <p>

     * During parsing, the text must match a known zone or offset.

     * There are two types of zone ID, offset-based, such as '+01:30' and

     * region-based, such as 'Europe/London'. These are parsed differently.

     * If the parse starts with '+', '-', 'UT', 'UTC' or 'GMT', then the parser

     * expects an offset-based zone and will not match region-based zones.

     * The offset ID, such as '+02:30', may be at the start of the parse,

     * or prefixed by  'UT', 'UTC' or 'GMT'. The offset ID parsing is

     * equivalent to using {@link #appendOffset(String, String)} using the

     * arguments 'HH:MM:ss' and the no offset string '0'.

     * If the parse starts with 'UT', 'UTC' or 'GMT', and the parser cannot

     * match a following offset ID, then {@link ZoneOffset#UTC} is selected.

     * In all other cases, the list of known region-based zones is used to

     * find the longest available match. If no match is found, and the parse

     * starts with 'Z', then {@code ZoneOffset.UTC} is selected.

     * The parser uses the {@linkplain #parseCaseInsensitive() case sensitive} setting.

     * <p>

     * For example, the following will parse:

     * <pre>

     *   "Europe/London"           -- ZoneId.of("Europe/London")

     *   "Z"                       -- ZoneOffset.UTC

     *   "UT"                      -- ZoneId.of("UT")

     *   "UTC"                     -- ZoneId.of("UTC")

     *   "GMT"                     -- ZoneId.of("GMT")

     *   "+01:30"                  -- ZoneOffset.of("+01:30")

     *   "UT+01:30"                -- ZoneOffset.of("+01:30")

     *   "UTC+01:30"               -- ZoneOffset.of("+01:30")

     *   "GMT+01:30"               -- ZoneOffset.of("+01:30")

     * </pre>

     * <p>

     * Note that this method is identical to {@code appendZoneId()} except

     * in the mechanism used to obtain the zone.

     * Note also that parsing accepts offsets, whereas formatting will never

     * produce one.

     *

     * @return this, for chaining, not null

     * @see #appendZoneId()

     */

    public DateTimeFormatterBuilder appendZoneRegionId() {

        appendInternal(new ZoneIdPrinterParser(QUERY_REGION_ONLY, "ZoneRegionId()"));

        return this;

    }

    /**

     * Appends the time-zone ID, such as 'Europe/Paris' or '+02:00', to

     * the formatter, using the best available zone ID.

     * <p>

     * This appends an instruction to format/parse the best available

     * zone or offset ID to the builder.

     * The zone ID is obtained in a lenient manner that first attempts to

     * find a true zone ID, such as that on {@code ZonedDateTime}, and

     * then attempts to find an offset, such as that on {@code OffsetDateTime}.

     * <p>

     * During formatting, the zone is obtained using a mechanism equivalent

     * to querying the temporal with {@link TemporalQueries#zone()}.

     * It will be printed using the result of {@link ZoneId#getId()}.

     * If the zone cannot be obtained then an exception is thrown unless the

     * section of the formatter is optional.

     * <p>

     * During parsing, the text must match a known zone or offset.

     * There are two types of zone ID, offset-based, such as '+01:30' and

     * region-based, such as 'Europe/London'. These are parsed differently.

     * If the parse starts with '+', '-', 'UT', 'UTC' or 'GMT', then the parser

     * expects an offset-based zone and will not match region-based zones.

     * The offset ID, such as '+02:30', may be at the start of the parse,

     * or prefixed by  'UT', 'UTC' or 'GMT'. The offset ID parsing is

     * equivalent to using {@link #appendOffset(String, String)} using the

     * arguments 'HH:MM:ss' and the no offset string '0'.

     * If the parse starts with 'UT', 'UTC' or 'GMT', and the parser cannot

     * match a following offset ID, then {@link ZoneOffset#UTC} is selected.

     * In all other cases, the list of known region-based zones is used to

     * find the longest available match. If no match is found, and the parse

     * starts with 'Z', then {@code ZoneOffset.UTC} is selected.

     * The parser uses the {@linkplain #parseCaseInsensitive() case sensitive} setting.

     * <p>

     * For example, the following will parse:

     * <pre>

     *   "Europe/London"           -- ZoneId.of("Europe/London")

     *   "Z"                       -- ZoneOffset.UTC

     *   "UT"                      -- ZoneId.of("UT")

     *   "UTC"                     -- ZoneId.of("UTC")

     *   "GMT"                     -- ZoneId.of("GMT")

     *   "+01:30"                  -- ZoneOffset.of("+01:30")

     *   "UT+01:30"                -- ZoneOffset.of("UT+01:30")

     *   "UTC+01:30"               -- ZoneOffset.of("UTC+01:30")

     *   "GMT+01:30"               -- ZoneOffset.of("GMT+01:30")

     * </pre>

     * <p>

     * Note that this method is identical to {@code appendZoneId()} except

     * in the mechanism used to obtain the zone.

     *

     * @return this, for chaining, not null

     * @see #appendZoneId()

     */

    public DateTimeFormatterBuilder appendZoneOrOffsetId() {

        appendInternal(new ZoneIdPrinterParser(TemporalQueries.zone(), "ZoneOrOffsetId()"));

        return this;

    }

    /**

     * Appends the time-zone name, such as 'British Summer Time', to the formatter.

     * <p>

     * This appends an instruction to format/parse the textual name of the zone to

     * the builder.

     * <p>

     * During formatting, the zone is obtained using a mechanism equivalent

     * to querying the temporal with {@link TemporalQueries#zoneId()}.

     * If the zone is a {@code ZoneOffset} it will be printed using the

     * result of {@link ZoneOffset#getId()}.

     * If the zone is not an offset, the textual name will be looked up

     * for the locale set in the {@link DateTimeFormatter}.

     * If the temporal object being printed represents an instant, then the text

     * will be the summer or winter time text as appropriate.

     * If the lookup for text does not find any suitable result, then the

     * {@link ZoneId#getId() ID} will be printed instead.

     * If the zone cannot be obtained then an exception is thrown unless the

     * section of the formatter is optional.

     * <p>

     * During parsing, either the textual zone name, the zone ID or the offset

     * is accepted. Many textual zone names are not unique, such as CST can be

     * for both "Central Standard Time" and "China Standard Time". In this

     * situation, the zone id will be determined by the region information from

     * formatter's  {@link DateTimeFormatter#getLocale() locale} and the standard

     * zone id for that area, for example, America/New_York for the America Eastern

     * zone. The {@link #appendZoneText(TextStyle, Set)} may be used

     * to specify a set of preferred {@link ZoneId} in this situation.

     *

     * @param textStyle  the text style to use, not null

     * @return this, for chaining, not null

     */

    public DateTimeFormatterBuilder appendZoneText(TextStyle textStyle) {

        appendInternal(new ZoneTextPrinterParser(textStyle, null));

        return this;

    }

    /**

     * Appends the time-zone name, such as 'British Summer Time', to the formatter.

     * <p>

     * This appends an instruction to format/parse the textual name of the zone to

     * the builder.

     * <p>

     * During formatting, the zone is obtained using a mechanism equivalent

     * to querying the temporal with {@link TemporalQueries#zoneId()}.

     * If the zone is a {@code ZoneOffset} it will be printed using the

     * result of {@link ZoneOffset#getId()}.

     * If the zone is not an offset, the textual name will be looked up

     * for the locale set in the {@link DateTimeFormatter}.

     * If the temporal object being printed represents an instant, then the text

     * will be the summer or winter time text as appropriate.

     * If the lookup for text does not find any suitable result, then the

     * {@link ZoneId#getId() ID} will be printed instead.

     * If the zone cannot be obtained then an exception is thrown unless the

     * section of the formatter is optional.

     * <p>

     * During parsing, either the textual zone name, the zone ID or the offset

     * is accepted. Many textual zone names are not unique, such as CST can be

     * for both "Central Standard Time" and "China Standard Time". In this

     * situation, the zone id will be determined by the region information from

     * formatter's  {@link DateTimeFormatter#getLocale() locale} and the standard

     * zone id for that area, for example, America/New_York for the America Eastern

     * zone. This method also allows a set of preferred {@link ZoneId} to be

     * specified for parsing. The matched preferred zone id will be used if the

     * textural zone name being parsed is not unique.

     * <p>

     * If the zone cannot be parsed then an exception is thrown unless the

     * section of the formatter is optional.

     *

     * @param textStyle  the text style to use, not null

     * @param preferredZones  the set of preferred zone ids, not null

     * @return this, for chaining, not null

     */

    public DateTimeFormatterBuilder appendZoneText(TextStyle textStyle,

                                                   Set<ZoneId> preferredZones) {

        Objects.requireNonNull(preferredZones, "preferredZones");

        appendInternal(new ZoneTextPrinterParser(textStyle, preferredZones));