text: /*
  ********************************************************************************
  *   Copyright (C) 1997-2014, International Business Machines
  *   Corporation and others.  All Rights Reserved.
  ********************************************************************************
  *
  * File DECIMFMT.H
  *
  * Modification History:
  *
  *   Date        Name        Description
  *   02/19/97    aliu        Converted from java.
  *   03/20/97    clhuang     Updated per C++ implementation.
  *   04/03/97    aliu        Rewrote parsing and formatting completely, and
  *                           cleaned up and debugged.  Actually works now.
  *   04/17/97    aliu        Changed DigitCount to int per code review.
  *   07/10/97    helena      Made ParsePosition a class and get rid of the function
  *                           hiding problems.
  *   09/09/97    aliu        Ported over support for exponential formats.
  *   07/20/98    stephen     Changed documentation
  *   01/30/13    emmons      Added Scaling methods
  ********************************************************************************
  */
  
  #ifndef DECIMFMT_H
  #define DECIMFMT_H
  
  #include "unicode/utypes.h"
  /**
   * \file
   * \brief C++ API: Formats decimal numbers.
   */
  
  #if !UCONFIG_NO_FORMATTING
  
  #include "unicode/dcfmtsym.h"
  #include "unicode/numfmt.h"
  #include "unicode/locid.h"
  #include "unicode/fpositer.h"
  #include "unicode/stringpiece.h"
  #include "unicode/curramt.h"
  #include "unicode/enumset.h"
  
  /**
   * \def UNUM_DECIMALFORMAT_INTERNAL_SIZE
   * @internal
   */
  #if UCONFIG_FORMAT_FASTPATHS_49
  #define UNUM_DECIMALFORMAT_INTERNAL_SIZE 16
  #endif
  
  U_NAMESPACE_BEGIN
  
  class DigitList;
  class ChoiceFormat;
  class CurrencyPluralInfo;
  class Hashtable;
  class UnicodeSet;
  class FieldPositionHandler;
  class DecimalFormatStaticSets;
  class FixedDecimal;
  
  // explicit template instantiation. see digitlst.h
  #if defined (_MSC_VER)
  template class U_I18N_API    EnumSet<UNumberFormatAttribute,
              UNUM_MAX_NONBOOLEAN_ATTRIBUTE+1,
              UNUM_LIMIT_BOOLEAN_ATTRIBUTE>;
  #endif
  
  /**
   * DecimalFormat is a concrete subclass of NumberFormat that formats decimal
   * numbers. It has a variety of features designed to make it possible to parse
   * and format numbers in any locale, including support for Western, Arabic, or
   * Indic digits.  It also supports different flavors of numbers, including
   * integers ("123"), fixed-point numbers ("123.4"), scientific notation
   * ("1.23E4"), percentages ("12%"), and currency amounts ("$123", "USD123",
   * "123 US dollars").  All of these flavors can be easily localized.
   *
   * <p>To obtain a NumberFormat for a specific locale (including the default
   * locale) call one of NumberFormat's factory methods such as
   * createInstance(). Do not call the DecimalFormat constructors directly, unless
   * you know what you are doing, since the NumberFormat factory methods may
   * return subclasses other than DecimalFormat.
   *
   * <p><strong>Example Usage</strong>
   *
   * \code
   *     // Normally we would have a GUI with a menu for this
   *     int32_t locCount;
   *     const Locale* locales = NumberFormat::getAvailableLocales(locCount);
   *
   *     double myNumber = -1234.56;
   *     UErrorCode success = U_ZERO_ERROR;
   *     NumberFormat* form;
   *
   *     // Print out a number with the localized number, currency and percent
   *     // format for each locale.
   *     UnicodeString countryName;
   *     UnicodeString displayName;
   *     UnicodeString str;
   *     UnicodeString pattern;
   *     Formattable fmtable;
   *     for (int32_t j = 0; j < 3; ++j) {
   *         cout << endl << "FORMAT " << j << endl;
   *         for (int32_t i = 0; i < locCount; ++i) {
   *             if (locales[i].getCountry(countryName).size() == 0) {
   *                 // skip language-only
   *                 continue;
   *             }
   *             switch (j) {
   *             case 0:
   *                 form = NumberFormat::createInstance(locales[i], success ); break;
   *             case 1:
   *                 form = NumberFormat::createCurrencyInstance(locales[i], success ); break;
   *             default:
   *                 form = NumberFormat::createPercentInstance(locales[i], success ); break;
   *             }
   *             if (form) {
   *                 str.remove();
   *                 pattern = ((DecimalFormat*)form)->toPattern(pattern);
   *                 cout << locales[i].getDisplayName(displayName) << ": " << pattern;
   *                 cout << "  ->  " << form->format(myNumber,str) << endl;
   *                 form->parse(form->format(myNumber,str), fmtable, success);
   *                 delete form;
   *             }
   *         }
   *     }
   * \endcode
   * <P>
   * Another example use createInstance(style)
   * <P>
   * <pre>
   * <strong>// Print out a number using the localized number, currency,
   * // percent, scientific, integer, iso currency, and plural currency
   * // format for each locale</strong>
   * Locale* locale = new Locale("en", "US");
   * double myNumber = 1234.56;
   * UErrorCode success = U_ZERO_ERROR;
   * UnicodeString str;
   * Formattable fmtable;
   * for (int j=NumberFormat::kNumberStyle;
   *      j<=NumberFormat::kPluralCurrencyStyle;
   *      ++j) {
   *     NumberFormat* format = NumberFormat::createInstance(locale, j, success);
   *     str.remove();
   *     cout << "format result " << form->format(myNumber, str) << endl;
   *     format->parse(form->format(myNumber, str), fmtable, success);
   * }</pre>
   *
   *
   * <p><strong>Patterns</strong>
   *
   * <p>A DecimalFormat consists of a <em>pattern</em> and a set of
   * <em>symbols</em>.  The pattern may be set directly using
   * applyPattern(), or indirectly using other API methods which
   * manipulate aspects of the pattern, such as the minimum number of integer
   * digits.  The symbols are stored in a DecimalFormatSymbols
   * object.  When using the NumberFormat factory methods, the
   * pattern and symbols are read from ICU's locale data.
   *
   * <p><strong>Special Pattern Characters</strong>
   *
   * <p>Many characters in a pattern are taken literally; they are matched during
   * parsing and output unchanged during formatting.  Special characters, on the
   * other hand, stand for other characters, strings, or classes of characters.
   * For example, the '#' character is replaced by a localized digit.  Often the
   * replacement character is the same as the pattern character; in the U.S. locale,
   * the ',' grouping character is replaced by ','.  However, the replacement is
   * still happening, and if the symbols are modified, the grouping character
   * changes.  Some special characters affect the behavior of the formatter by
   * their presence; for example, if the percent character is seen, then the
   * value is multiplied by 100 before being displayed.
   *
   * <p>To insert a special character in a pattern as a literal, that is, without
   * any special meaning, the character must be quoted.  There are some exceptions to
   * this which are noted below.
   *
   * <p>The characters listed here are used in non-localized patterns.  Localized
   * patterns use the corresponding characters taken from this formatter's
   * DecimalFormatSymbols object instead, and these characters lose
   * their special status.  Two exceptions are the currency sign and quote, which
   * are not localized.
   *
   * <table border=0 cellspacing=3 cellpadding=0>
   *   <tr bgcolor="#ccccff">
   *     <td align=left><strong>Symbol</strong>
   *     <td align=left><strong>Location</strong>
   *     <td align=left><strong>Localized?</strong>
   *     <td align=left><strong>Meaning</strong>
   *   <tr valign=top>
   *     <td><code>0</code>
   *     <td>Number
   *     <td>Yes
   *     <td>Digit
   *   <tr valign=top bgcolor="#eeeeff">
   *     <td><code>1-9</code>
   *     <td>Number
   *     <td>Yes
   *     <td>'1' through '9' indicate rounding.
   *   <tr valign=top>
   *     <td><code>\htmlonly&#x40;\endhtmlonly</code> <!--doxygen doesn't like @-->
   *     <td>Number
   *     <td>No
   *     <td>Significant digit
   *   <tr valign=top bgcolor="#eeeeff">
   *     <td><code>#</code>
   *     <td>Number
   *     <td>Yes
   *     <td>Digit, zero shows as absent
   *   <tr valign=top>
   *     <td><code>.</code>
   *     <td>Number
   *     <td>Yes
   *     <td>Decimal separator or monetary decimal separator
   *   <tr valign=top bgcolor="#eeeeff">
   *     <td><code>-</code>
   *     <td>Number
   *     <td>Yes
   *     <td>Minus sign
   *   <tr valign=top>
   *     <td><code>,</code>
   *     <td>Number
   *     <td>Yes
   *     <td>Grouping separator
   *   <tr valign=top bgcolor="#eeeeff">
   *     <td><code>E</code>
   *     <td>Number
   *     <td>Yes
   *     <td>Separates mantissa and exponent in scientific notation.
   *         <em>Need not be quoted in prefix or suffix.</em>
   *   <tr valign=top>
   *     <td><code>+</code>
   *     <td>Exponent
   *     <td>Yes
   *     <td>Prefix positive exponents with localized plus sign.
   *         <em>Need not be quoted in prefix or suffix.</em>
   *   <tr valign=top bgcolor="#eeeeff">
   *     <td><code>;</code>
   *     <td>Subpattern boundary
   *     <td>Yes
   *     <td>Separates positive and negative subpatterns
   *   <tr valign=top>
   *     <td><code>\%</code>
   *     <td>Prefix or suffix
   *     <td>Yes
   *     <td>Multiply by 100 and show as percentage
   *   <tr valign=top bgcolor="#eeeeff">
   *     <td><code>\\u2030</code>
   *     <td>Prefix or suffix
   *     <td>Yes
   *     <td>Multiply by 1000 and show as per mille
   *   <tr valign=top>
   *     <td><code>\htmlonly&curren;\endhtmlonly</code> (<code>\\u00A4</code>)
   *     <td>Prefix or suffix
   *     <td>No
   *     <td>Currency sign, replaced by currency symbol.  If
   *         doubled, replaced by international currency symbol.
   *         If tripled, replaced by currency plural names, for example,
   *         "US dollar" or "US dollars" for America.
   *         If present in a pattern, the monetary decimal separator
   *         is used instead of the decimal separator.
   *   <tr valign=top bgcolor="#eeeeff">
   *     <td><code>'</code>
   *     <td>Prefix or suffix
   *     <td>No
   *     <td>Used to quote special characters in a prefix or suffix,
   *         for example, <code>"'#'#"</code> formats 123 to
   *         <code>"#123"</code>.  To create a single quote
   *         itself, use two in a row: <code>"# o''clock"</code>.
   *   <tr valign=top>
   *     <td><code>*</code>
   *     <td>Prefix or suffix boundary
   *     <td>Yes
   *     <td>Pad escape, precedes pad character
   * </table>
   *
   * <p>A DecimalFormat pattern contains a postive and negative
   * subpattern, for example, "#,##0.00;(#,##0.00)".  Each subpattern has a
   * prefix, a numeric part, and a suffix.  If there is no explicit negative
   * subpattern, the negative subpattern is the localized minus sign prefixed to the
   * positive subpattern. That is, "0.00" alone is equivalent to "0.00;-0.00".  If there
   * is an explicit negative subpattern, it serves only to specify the negative
   * prefix and suffix; the number of digits, minimal digits, and other
   * characteristics are ignored in the negative subpattern. That means that
   * "#,##0.0#;(#)" has precisely the same result as "#,##0.0#;(#,##0.0#)".
   *
   * <p>The prefixes, suffixes, and various symbols used for infinity, digits,
   * thousands separators, decimal separators, etc. may be set to arbitrary
   * values, and they will appear properly during formatting.  However, care must
   * be taken that the symbols and strings do not conflict, or parsing will be
   * unreliable.  For example, either the positive and negative prefixes or the
   * suffixes must be distinct for parse() to be able
   * to distinguish positive from negative values.  Another example is that the
   * decimal separator and thousands separator should be distinct characters, or
   * parsing will be impossible.
   *
   * <p>The <em>grouping separator</em> is a character that separates clusters of
   * integer digits to make large numbers more legible.  It commonly used for
   * thousands, but in some locales it separates ten-thousands.  The <em>grouping
   * size</em> is the number of digits between the grouping separators, such as 3
   * for "100,000,000" or 4 for "1 0000 0000". There are actually two different
   * grouping sizes: One used for the least significant integer digits, the
   * <em>primary grouping size</em>, and one used for all others, the
   * <em>secondary grouping size</em>.  In most locales these are the same, but
   * sometimes they are different. For example, if the primary grouping interval
   * is 3, and the secondary is 2, then this corresponds to the pattern
   * "#,##,##0", and the number 123456789 is formatted as "12,34,56,789".  If a
   * pattern contains multiple grouping separators, the interval between the last
   * one and the end of the integer defines the primary grouping size, and the
   * interval between the last two defines the secondary grouping size. All others
   * are ignored, so "#,##,###,####" == "###,###,####" == "##,#,###,####".
   *
   * <p>Illegal patterns, such as "#.#.#" or "#.###,###", will cause
   * DecimalFormat to set a failing UErrorCode.
   *
   * <p><strong>Pattern BNF</strong>
   *
   * <pre>
   * pattern    := subpattern (';' subpattern)?
   * subpattern := prefix? number exponent? suffix?
   * number     := (integer ('.' fraction)?) | sigDigits
   * prefix     := '\\u0000'..'\\uFFFD' - specialCharacters
   * suffix     := '\\u0000'..'\\uFFFD' - specialCharacters
   * integer    := '#'* '0'* '0'
   * fraction   := '0'* '#'*
   * sigDigits  := '#'* '@' '@'* '#'*
   * exponent   := 'E' '+'? '0'* '0'
   * padSpec    := '*' padChar
   * padChar    := '\\u0000'..'\\uFFFD' - quote
   * &nbsp;
   * Notation:
   *   X*       0 or more instances of X
   *   X?       0 or 1 instances of X
   *   X|Y      either X or Y
   *   C..D     any character from C up to D, inclusive
   *   S-T      characters in S, except those in T
   * </pre>
   * The first subpattern is for positive numbers. The second (optional)
   * subpattern is for negative numbers.
   *
   * <p>Not indicated in the BNF syntax above:
   *
   * <ul><li>The grouping separator ',' can occur inside the integer and
   * sigDigits elements, between any two pattern characters of that
   * element, as long as the integer or sigDigits element is not
   * followed by the exponent element.
   *
   * <li>Two grouping intervals are recognized: That between the
   *     decimal point and the first grouping symbol, and that
   *     between the first and second grouping symbols. These
   *     intervals are identical in most locales, but in some
   *     locales they differ. For example, the pattern
   *     &quot;#,##,###&quot; formats the number 123456789 as
   *     &quot;12,34,56,789&quot;.</li>
   *
   * <li>The pad specifier <code>padSpec</code> may appear before the prefix,
   * after the prefix, before the suffix, after the suffix, or not at all.
   *
   * <li>In place of '0', the digits '1' through '9' may be used to
   * indicate a rounding increment.
   * </ul>
   *
   * <p><strong>Parsing</strong>
   *
   * <p>DecimalFormat parses all Unicode characters that represent
   * decimal digits, as defined by u_charDigitValue().  In addition,
   * DecimalFormat also recognizes as digits the ten consecutive
   * characters starting with the localized zero digit defined in the
   * DecimalFormatSymbols object.  During formatting, the
   * DecimalFormatSymbols-based digits are output.
   *
   * <p>During parsing, grouping separators are ignored.
   *
   * <p>For currency parsing, the formatter is able to parse every currency
   * style formats no matter which style the formatter is constructed with.
   * For example, a formatter instance gotten from
   * NumberFormat.getInstance(ULocale, NumberFormat.CURRENCYSTYLE) can parse
   * formats such as "USD1.00" and "3.00 US dollars".
   *
   * <p>If parse(UnicodeString&,Formattable&,ParsePosition&)
   * fails to parse a string, it leaves the parse position unchanged.
   * The convenience method parse(UnicodeString&,Formattable&,UErrorCode&)
   * indicates parse failure by setting a failing
   * UErrorCode.
   *
   * <p><strong>Formatting</strong>
   *
   * <p>Formatting is guided by several parameters, all of which can be
   * specified either using a pattern or using the API.  The following
   * description applies to formats that do not use <a href="#sci">scientific
   * notation</a> or <a href="#sigdig">significant digits</a>.
   *
   * <ul><li>If the number of actual integer digits exceeds the
   * <em>maximum integer digits</em>, then only the least significant
   * digits are shown.  For example, 1997 is formatted as "97" if the
   * maximum integer digits is set to 2.
   *
   * <li>If the number of actual integer digits is less than the
   * <em>minimum integer digits</em>, then leading zeros are added.  For
   * example, 1997 is formatted as "01997" if the minimum integer digits
   * is set to 5.
   *
   * <li>If the number of actual fraction digits exceeds the <em>maximum
   * fraction digits</em>, then rounding is performed to the
   * maximum fraction digits.  For example, 0.125 is formatted as "0.12"
   * if the maximum fraction digits is 2.  This behavior can be changed
   * by specifying a rounding increment and/or a rounding mode.
   *
   * <li>If the number of actual fraction digits is less than the
   * <em>minimum fraction digits</em>, then trailing zeros are added.
   * For example, 0.125 is formatted as "0.1250" if the mimimum fraction
   * digits is set to 4.
   *
   * <li>Trailing fractional zeros are not displayed if they occur
   * <em>j</em> positions after the decimal, where <em>j</em> is less
   * than the maximum fraction digits. For example, 0.10004 is
   * formatted as "0.1" if the maximum fraction digits is four or less.
   * </ul>
   *
   * <p><strong>Special Values</strong>
   *
   * <p><code>NaN</code> is represented as a single character, typically
   * <code>\\uFFFD</code>.  This character is determined by the
   * DecimalFormatSymbols object.  This is the only value for which
   * the prefixes and suffixes are not used.
   *
   * <p>Infinity is represented as a single character, typically
   * <code>\\u221E</code>, with the positive or negative prefixes and suffixes
   * applied.  The infinity character is determined by the
   * DecimalFormatSymbols object.
   *
   * <a name="sci"><strong>Scientific Notation</strong></a>
   *
   * <p>Numbers in scientific notation are expressed as the product of a mantissa
   * and a power of ten, for example, 1234 can be expressed as 1.234 x 10<sup>3</sup>. The
   * mantissa is typically in the half-open interval [1.0, 10.0) or sometimes [0.0, 1.0),
   * but it need not be.  DecimalFormat supports arbitrary mantissas.
   * DecimalFormat can be instructed to use scientific
   * notation through the API or through the pattern.  In a pattern, the exponent
   * character immediately followed by one or more digit characters indicates
   * scientific notation.  Example: "0.###E0" formats the number 1234 as
   * "1.234E3".
   *
   * <ul>
   * <li>The number of digit characters after the exponent character gives the
   * minimum exponent digit count.  There is no maximum.  Negative exponents are
   * formatted using the localized minus sign, <em>not</em> the prefix and suffix
   * from the pattern.  This allows patterns such as "0.###E0 m/s".  To prefix
   * positive exponents with a localized plus sign, specify '+' between the
   * exponent and the digits: "0.###E+0" will produce formats "1E+1", "1E+0",
   * "1E-1", etc.  (In localized patterns, use the localized plus sign rather than
   * '+'.)
   *
   * <li>The minimum number of integer digits is achieved by adjusting the
   * exponent.  Example: 0.00123 formatted with "00.###E0" yields "12.3E-4".  This
   * only happens if there is no maximum number of integer digits.  If there is a
   * maximum, then the minimum number of integer digits is fixed at one.
   *
   * <li>The maximum number of integer digits, if present, specifies the exponent
   * grouping.  The most common use of this is to generate <em>engineering
   * notation</em>, in which the exponent is a multiple of three, e.g.,
   * "##0.###E0".  The number 12345 is formatted using "##0.####E0" as "12.345E3".
   *
   * <li>When using scientific notation, the formatter controls the
   * digit counts using significant digits logic.  The maximum number of
   * significant digits limits the total number of integer and fraction
   * digits that will be shown in the mantissa; it does not affect
   * parsing.  For example, 12345 formatted with "##0.##E0" is "12.3E3".
   * See the section on significant digits for more details.
   *
   * <li>The number of significant digits shown is determined as
   * follows: If areSignificantDigitsUsed() returns false, then the
   * minimum number of significant digits shown is one, and the maximum
   * number of significant digits shown is the sum of the <em>minimum
   * integer</em> and <em>maximum fraction</em> digits, and is
   * unaffected by the maximum integer digits.  If this sum is zero,
   * then all significant digits are shown.  If
   * areSignificantDigitsUsed() returns true, then the significant digit
   * counts are specified by getMinimumSignificantDigits() and
   * getMaximumSignificantDigits().  In this case, the number of
   * integer digits is fixed at one, and there is no exponent grouping.
   *
   * <li>Exponential patterns may not contain grouping separators.
   * </ul>
   *
   * <a name="sigdig"><strong>Significant Digits</strong></a>
   *
   * <code>DecimalFormat</code> has two ways of controlling how many
   * digits are shows: (a) significant digits counts, or (b) integer and
   * fraction digit counts.  Integer and fraction digit counts are
   * described above.  When a formatter is using significant digits
   * counts, the number of integer and fraction digits is not specified
   * directly, and the formatter settings for these counts are ignored.
   * Instead, the formatter uses however many integer and fraction
   * digits are required to display the specified number of significant
   * digits.  Examples:
   *
   * <table border=0 cellspacing=3 cellpadding=0>
   *   <tr bgcolor="#ccccff">
   *     <td align=left>Pattern
   *     <td align=left>Minimum significant digits
   *     <td align=left>Maximum significant digits
   *     <td align=left>Number
   *     <td align=left>Output of format()
   *   <tr valign=top>
   *     <td><code>\@\@\@</code>
   *     <td>3
   *     <td>3
   *     <td>12345
   *     <td><code>12300</code>
   *   <tr valign=top bgcolor="#eeeeff">
   *     <td><code>\@\@\@</code>
   *     <td>3
   *     <td>3
   *     <td>0.12345
   *     <td><code>0.123</code>
   *   <tr valign=top>
   *     <td><code>\@\@##</code>
   *     <td>2
   *     <td>4
   *     <td>3.14159
   *     <td><code>3.142</code>
   *   <tr valign=top bgcolor="#eeeeff">
   *     <td><code>\@\@##</code>
   *     <td>2
   *     <td>4
   *     <td>1.23004
   *     <td><code>1.23</code>
   * </table>
   *
   * <ul>
   * <li>Significant digit counts may be expressed using patterns that
   * specify a minimum and maximum number of significant digits.  These
   * are indicated by the <code>'@'</code> and <code>'#'</code>
   * characters.  The minimum number of significant digits is the number
   * of <code>'@'</code> characters.  The maximum number of significant
   * digits is the number of <code>'@'</code> characters plus the number
   * of <code>'#'</code> characters following on the right.  For
   * example, the pattern <code>"@@@"</code> indicates exactly 3
   * significant digits.  The pattern <code>"@##"</code> indicates from
   * 1 to 3 significant digits.  Trailing zero digits to the right of
   * the decimal separator are suppressed after the minimum number of
   * significant digits have been shown.  For example, the pattern
   * <code>"@##"</code> formats the number 0.1203 as
   * <code>"0.12"</code>.
   *
   * <li>If a pattern uses significant digits, it may not contain a
   * decimal separator, nor the <code>'0'</code> pattern character.
   * Patterns such as <code>"@00"</code> or <code>"@.###"</code> are
   * disallowed.
   *
   * <li>Any number of <code>'#'</code> characters may be prepended to
   * the left of the leftmost <code>'@'</code> character.  These have no
   * effect on the minimum and maximum significant digits counts, but
   * may be used to position grouping separators.  For example,
   * <code>"#,#@#"</code> indicates a minimum of one significant digits,
   * a maximum of two significant digits, and a grouping size of three.
   *
   * <li>In order to enable significant digits formatting, use a pattern
   * containing the <code>'@'</code> pattern character.  Alternatively,
   * call setSignificantDigitsUsed(TRUE).
   *
   * <li>In order to disable significant digits formatting, use a
   * pattern that does not contain the <code>'@'</code> pattern
   * character. Alternatively, call setSignificantDigitsUsed(FALSE).
   *
   * <li>The number of significant digits has no effect on parsing.
   *
   * <li>Significant digits may be used together with exponential notation. Such
   * patterns are equivalent to a normal exponential pattern with a minimum and
   * maximum integer digit count of one, a minimum fraction digit count of
   * <code>getMinimumSignificantDigits() - 1</code>, and a maximum fraction digit
   * count of <code>getMaximumSignificantDigits() - 1</code>. For example, the
   * pattern <code>"@@###E0"</code> is equivalent to <code>"0.0###E0"</code>.
   *
   * <li>If signficant digits are in use, then the integer and fraction
   * digit counts, as set via the API, are ignored.  If significant
   * digits are not in use, then the signficant digit counts, as set via
   * the API, are ignored.
   *
   * </ul>
   *
   * <p><strong>Padding</strong>
   *
   * <p>DecimalFormat supports padding the result of
   * format() to a specific width.  Padding may be specified either
   * through the API or through the pattern syntax.  In a pattern the pad escape
   * character, followed by a single pad character, causes padding to be parsed
   * and formatted.  The pad escape character is '*' in unlocalized patterns, and
   * can be localized using DecimalFormatSymbols::setSymbol() with a
   * DecimalFormatSymbols::kPadEscapeSymbol
   * selector.  For example, <code>"$*x#,##0.00"</code> formats 123 to
   * <code>"$xx123.00"</code>, and 1234 to <code>"$1,234.00"</code>.
   *
   * <ul>
   * <li>When padding is in effect, the width of the positive subpattern,
   * including prefix and suffix, determines the format width.  For example, in
   * the pattern <code>"* #0 o''clock"</code>, the format width is 10.
   *
   * <li>The width is counted in 16-bit code units (UChars).
   *
   * <li>Some parameters which usually do not matter have meaning when padding is
   * used, because the pattern width is significant with padding.  In the pattern
   * "* ##,##,#,##0.##", the format width is 14.  The initial characters "##,##,"
   * do not affect the grouping size or maximum integer digits, but they do affect
   * the format width.
   *
   * <li>Padding may be inserted at one of four locations: before the prefix,
   * after the prefix, before the suffix, or after the suffix.  If padding is
   * specified in any other location, applyPattern()
   * sets a failing UErrorCode.  If there is no prefix,
   * before the prefix and after the prefix are equivalent, likewise for the
   * suffix.
   *
   * <li>When specified in a pattern, the 32-bit code point immediately
   * following the pad escape is the pad character. This may be any character,
   * including a special pattern character. That is, the pad escape
   * <em>escapes</em> the following character. If there is no character after
   * the pad escape, then the pattern is illegal.
   *
   * </ul>
   *
   * <p><strong>Rounding</strong>
   *
   * <p>DecimalFormat supports rounding to a specific increment.  For
   * example, 1230 rounded to the nearest 50 is 1250.  1.234 rounded to the
   * nearest 0.65 is 1.3.  The rounding increment may be specified through the API
   * or in a pattern.  To specify a rounding increment in a pattern, include the
   * increment in the pattern itself.  "#,#50" specifies a rounding increment of
   * 50.  "#,##0.05" specifies a rounding increment of 0.05.
   *
   * <p>In the absense of an explicit rounding increment numbers are
   * rounded to their formatted width.
   *
   * <ul>
   * <li>Rounding only affects the string produced by formatting.  It does
   * not affect parsing or change any numerical values.
   *
   * <li>A <em>rounding mode</em> determines how values are rounded; see
   * DecimalFormat::ERoundingMode.  The default rounding mode is
   * DecimalFormat::kRoundHalfEven.  The rounding mode can only be set
   * through the API; it can not be set with a pattern.
   *
   * <li>Some locales use rounding in their currency formats to reflect the
   * smallest currency denomination.
   *
   * <li>In a pattern, digits '1' through '9' specify rounding, but otherwise
   * behave identically to digit '0'.
   * </ul>
   *
   * <p><strong>Synchronization</strong>
   *
   * <p>DecimalFormat objects are not synchronized.  Multiple
   * threads should not access one formatter concurrently.
   *
   * <p><strong>Subclassing</strong>
   *
   * <p><em>User subclasses are not supported.</em> While clients may write
   * subclasses, such code will not necessarily work and will not be
   * guaranteed to work stably from release to release.
   */
  class U_I18N_API DecimalFormat: public NumberFormat {
  public:
      /**
       * Rounding mode.
       * @stable ICU 2.4
       */
      enum ERoundingMode {
          kRoundCeiling,  /**< Round towards positive infinity */
          kRoundFloor,    /**< Round towards negative infinity */
          kRoundDown,     /**< Round towards zero */
          kRoundUp,       /**< Round away from zero */
          kRoundHalfEven, /**< Round towards the nearest integer, or
                               towards the nearest even integer if equidistant */
          kRoundHalfDown, /**< Round towards the nearest integer, or
                               towards zero if equidistant */
          kRoundHalfUp,   /**< Round towards the nearest integer, or
                               away from zero if equidistant */
          /**
            *  Return U_FORMAT_INEXACT_ERROR if number does not format exactly.
            *  @stable ICU 4.8
            */
          kRoundUnnecessary
      };
  
      /**
       * Pad position.
       * @stable ICU 2.4
       */
      enum EPadPosition {
          kPadBeforePrefix,
          kPadAfterPrefix,
          kPadBeforeSuffix,
          kPadAfterSuffix
      };
  
      /**
       * Create a DecimalFormat using the default pattern and symbols
       * for the default locale. This is a convenient way to obtain a
       * DecimalFormat when internationalization is not the main concern.
       * <P>
       * To obtain standard formats for a given locale, use the factory methods
       * on NumberFormat such as createInstance. These factories will
       * return the most appropriate sub-class of NumberFormat for a given
       * locale.
       * @param status    Output param set to success/failure code. If the
       *                  pattern is invalid this will be set to a failure code.
       * @stable ICU 2.0
       */
      DecimalFormat(UErrorCode& status);
  
      /**
       * Create a DecimalFormat from the given pattern and the symbols
       * for the default locale. This is a convenient way to obtain a
       * DecimalFormat when internationalization is not the main concern.
       * <P>
       * To obtain standard formats for a given locale, use the factory methods
       * on NumberFormat such as createInstance. These factories will
       * return the most appropriate sub-class of NumberFormat for a given
       * locale.
       * @param pattern   A non-localized pattern string.
       * @param status    Output param set to success/failure code. If the
       *                  pattern is invalid this will be set to a failure code.
       * @stable ICU 2.0
       */
      DecimalFormat(const UnicodeString& pattern,
                    UErrorCode& status);
  
      /**
       * Create a DecimalFormat from the given pattern and symbols.
       * Use this constructor when you need to completely customize the
       * behavior of the format.
       * <P>
       * To obtain standard formats for a given
       * locale, use the factory methods on NumberFormat such as
       * createInstance or createCurrencyInstance. If you need only minor adjustments
       * to a standard format, you can modify the format returned by
       * a NumberFormat factory method.
       *
       * @param pattern           a non-localized pattern string
       * @param symbolsToAdopt    the set of symbols to be used.  The caller should not
       *                          delete this object after making this call.
       * @param status            Output param set to success/failure code. If the
       *                          pattern is invalid this will be set to a failure code.
       * @stable ICU 2.0
       */
      DecimalFormat(  const UnicodeString& pattern,
                      DecimalFormatSymbols* symbolsToAdopt,
                      UErrorCode& status);
  
  #ifndef U_HIDE_INTERNAL_API
      /**
       * This API is for ICU use only.
       * Create a DecimalFormat from the given pattern, symbols, and style.
       *
       * @param pattern           a non-localized pattern string
       * @param symbolsToAdopt    the set of symbols to be used.  The caller should not
       *                          delete this object after making this call.
       * @param style             style of decimal format
       * @param status            Output param set to success/failure code. If the
       *                          pattern is invalid this will be set to a failure code.
       * @internal
       */
      DecimalFormat(  const UnicodeString& pattern,
                      DecimalFormatSymbols* symbolsToAdopt,
                      UNumberFormatStyle style,
                      UErrorCode& status);
  
  #if UCONFIG_HAVE_PARSEALLINPUT
      /**
       * @internal
       */
      void setParseAllInput(UNumberFormatAttributeValue value);
  #endif
  
  #endif  /* U_HIDE_INTERNAL_API */
  
  
      /**
       * Set an integer attribute on this DecimalFormat.
       * May return U_UNSUPPORTED_ERROR if this instance does not support
       * the specified attribute.
       * @param attr the attribute to set
       * @param newvalue new value
       * @param status the error type
       * @return *this - for chaining (example: format.setAttribute(...).setAttribute(...) )
       * @stable ICU 51
       */
      virtual DecimalFormat& setAttribute( UNumberFormatAttribute attr,
                                         int32_t newvalue,
                                         UErrorCode &status);
  
      /**
       * Get an integer
       * May return U_UNSUPPORTED_ERROR if this instance does not support
       * the specified attribute.
       * @param attr the attribute to set
       * @param status the error type
       * @return the attribute value. Undefined if there is an error.
       * @stable ICU 51
       */
      virtual int32_t getAttribute( UNumberFormatAttribute attr,
                                    UErrorCode &status) const;
  
      
      /**
       * Set whether or not grouping will be used in this format.
       * @param newValue    True, grouping will be used in this format.
       * @see getGroupingUsed
       * @draft ICU 53
       */
      virtual void setGroupingUsed(UBool newValue);
  
      /**
       * Sets whether or not numbers should be parsed as integers only.
       * @param value    set True, this format will parse numbers as integers
       *                 only.
       * @see isParseIntegerOnly
       * @draft ICU 53
       */
      virtual void setParseIntegerOnly(UBool value);
  
      /* Cannot use #ifndef U_HIDE_DRAFT_API for the following draft method since it is virtual */
      /**
       * Set a particular UDisplayContext value in the formatter, such as
       * UDISPCTX_CAPITALIZATION_FOR_STANDALONE.
       * @param value The UDisplayContext value to set.
       * @param status Input/output status. If at entry this indicates a failure
       *               status, the function will do nothing; otherwise this will be
       *               updated with any new status from the function. 
       * @draft ICU 53
       */
      virtual void setContext(UDisplayContext value, UErrorCode& status);
  
      /**
       * Create a DecimalFormat from the given pattern and symbols.
       * Use this constructor when you need to completely customize the
       * behavior of the format.
       * <P>
       * To obtain standard formats for a given
       * locale, use the factory methods on NumberFormat such as
       * createInstance or createCurrencyInstance. If you need only minor adjustments
       * to a standard format, you can modify the format returned by
       * a NumberFormat factory method.
       *
       * @param pattern           a non-localized pattern string
       * @param symbolsToAdopt    the set of symbols to be used.  The caller should not
       *                          delete this object after making this call.
       * @param parseError        Output param to receive errors occured during parsing
       * @param status            Output param set to success/failure code. If the
       *                          pattern is invalid this will be set to a failure code.
       * @stable ICU 2.0
       */
      DecimalFormat(  const UnicodeString& pattern,
                      DecimalFormatSymbols* symbolsToAdopt,
                      UParseError& parseError,
                      UErrorCode& status);
      /**
       * Create a DecimalFormat from the given pattern and symbols.
       * Use this constructor when you need to completely customize the
       * behavior of the format.
       * <P>
       * To obtain standard formats for a given
       * locale, use the factory methods on NumberFormat such as
       * createInstance or createCurrencyInstance. If you need only minor adjustments
       * to a standard format, you can modify the format returned by
       * a NumberFormat factory method.
       *
       * @param pattern           a non-localized pattern string
       * @param symbols   the set of symbols to be used
       * @param status            Output param set to success/failure code. If the
       *                          pattern is invalid this will be set to a failure code.
       * @stable ICU 2.0
       */
      DecimalFormat(  const UnicodeString& pattern,
                      const DecimalFormatSymbols& symbols,
                      UErrorCode& status);
  
      /**
       * Copy constructor.
       *
       * @param source    the DecimalFormat object to be copied from.
       * @stable ICU 2.0
       */
      DecimalFormat(const DecimalFormat& source);
  
      /**
       * Assignment operator.
       *
       * @param rhs    the DecimalFormat object to be copied.
       * @stable ICU 2.0
       */
      DecimalFormat& operator=(const DecimalFormat& rhs);
  
      /**
       * Destructor.
       * @stable ICU 2.0
       */
      virtual ~DecimalFormat();
  
      /**
       * Clone this Format object polymorphically. The caller owns the
       * result and should delete it when done.
       *
       * @return    a polymorphic copy of this DecimalFormat.
       * @stable ICU 2.0
       */
      virtual Format* clone(void) const;
  
      /**
       * Return true if the given Format objects are semantically equal.
       * Objects of different subclasses are considered unequal.
       *
       * @param other    the object to be compared with.
       * @return         true if the given Format objects are semantically equal.
       * @stable ICU 2.0
       */
      virtual UBool operator==(const Format& other) const;
  
  
      using NumberFormat::format;
  
      /**
       * Format a double or long number using base-10 representation.
       *
       * @param number    The value to be formatted.
       * @param appendTo  Output parameter to receive result.
       *                  Result is appended to existing contents.
       * @param pos       On input: an alignment field, if desired.
       *                  On output: the offsets of the alignment field.
       * @return          Reference to 'appendTo' parameter.
       * @stable ICU 2.0
       */
      virtual UnicodeString& format(double number,
                                    UnicodeString& appendTo,
                                    FieldPosition& pos) const;
  
  
      /**
       * Format a double or long number using base-10 representation.
       *
       * @param number    The value to be formatted.
       * @param appendTo  Output parameter to receive result.
       *                  Result is appended to existing contents.
       * @param pos       On input: an alignment field, if desired.
       *                  On output: the offsets of the alignment field.
       * @param status
       * @return          Reference to 'appendTo' parameter.
       * @internal
       */
      virtual UnicodeString& format(double number,
                                    UnicodeString& appendTo,
                                    FieldPosition& pos,
                                    UErrorCode &status) const;
  
      /**
       * Format a double or long number using base-10 representation.
       *
       * @param number    The value to be formatted.
       * @param appendTo  Output parameter to receive result.
       *                  Result is appended to existing contents.
       * @param posIter   On return, can be used to iterate over positions
       *                  of fields generated by this format call.
       *                  Can be NULL.
       * @param status    Output param filled with success/failure status.
       * @return          Reference to 'appendTo' parameter.
       * @stable 4.4
       */
      virtual UnicodeString& format(double number,
                                    UnicodeString& appendTo,
                                    FieldPositionIterator* posIter,
                                    UErrorCode& status) const;
  
      /**
       * Format a long number using base-10 representation.
       *
       * @param number    The value to be formatted.
       * @param appendTo  Output parameter to receive result.
       *                  Result is appended to existing contents.
       * @param pos       On input: an alignment field, if desired.
       *                  On output: the offsets of the alignment field.
       * @return          Reference to 'appendTo' parameter.
       * @stable ICU 2.0
       */
      virtual UnicodeString& format(int32_t number,
                                    UnicodeString& appendTo,
                                    FieldPosition& pos) const;
  
      /**
       * Format a long number using base-10 representation.
       *
       * @param number    The value to be formatted.
       * @param appendTo  Output parameter to receive result.
       *                  Result is appended to existing contents.
       * @param pos       On input: an alignment field, if desired.
       *                  On output: the offsets of the alignment field.
       * @return          Reference to 'appendTo' parameter.
       * @internal
       */
      virtual UnicodeString& format(int32_t number,
                                    UnicodeString& appendTo,
                                    FieldPosition& pos,
                                    UErrorCode &status) const;
  
      /**
       * Format a long number using base-10 representation.
       *
       * @param number    The value to be formatted.
       * @param appendTo  Output parameter to receive result.
       *                  Result is appended to existing contents.
       * @param posIter   On return, can be used to iterate over positions
       *                  of fields generated by this format call.
       *                  Can be NULL.
       * @param status    Output param filled with success/failure status.
       * @return          Reference to 'appendTo' parameter.
       * @stable 4.4
       */
      virtual UnicodeString& format(int32_t number,
                                    UnicodeString& appendTo,
                                    FieldPositionIterator* posIter,
                                    UErrorCode& status) const;
  
      /**
       * Format an int64 number using base-10 representation.
       *
       * @param number    The value to be formatted.
       * @param appendTo  Output parameter to receive result.
       *                  Result is appended to existing contents.
       * @param pos       On input: an alignment field, if desired.
       *                  On output: the offsets of the alignment field.
       * @return          Reference to 'appendTo' parameter.
       * @stable ICU 2.8
       */
      virtual UnicodeString& format(int64_t number,
                                    UnicodeString& appendTo,
                                    FieldPosition& pos) const;
  
      /**
       * Format an int64 number using base-10 representation.
       *
       * @param number    The value to be formatted.
       * @param appendTo  Output parameter to receive result.
       *                  Result is appended to existing contents.
       * @param pos       On input: an alignment field, if desired.
       *                  On output: the offsets of the alignment field.
       * @return          Reference to 'appendTo' parameter.
       * @internal
       */
      virtual UnicodeString& format(int64_t number,
                                    UnicodeString& appendTo,
                                    FieldPosition& pos,
                                    UErrorCode &status) const;
  
      /**
       * Format an int64 number using base-10 representation.
       *
       * @param number    The value to be formatted.
       * @param appendTo  Output parameter to receive result.
       *                  Result is appended to existing contents.
       * @param posIter   On return, can be used to iterate over positions
       *                  of fields generated by this format call.
       *                  Can be NULL.
       * @param status    Output param filled with success/failure status.
       * @return          Reference to 'appendTo' parameter.
       * @stable 4.4
       */
      virtual UnicodeString& format(int64_t number,
                                    UnicodeString& appendTo,
                                    FieldPositionIterator* posIter,
                                    UErrorCode& status) const;
  
      /**
       * Format a decimal number.
       * The syntax of the unformatted number is a "numeric string"
       * as defined in the Decimal Arithmetic Specification, available at
       * http://speleotrove.com/decimal
       *
       * @param number    The unformatted number, as a string.
       * @param appendTo  Output parameter to receive result.
       *                  Result is appended to existing contents.
       * @param posIter   On return, can be used to iterate over positions
       *                  of fields generated by this format call.
       *                  Can be NULL.
       * @param status    Output param filled with success/failure status.
       * @return          Reference to 'appendTo' parameter.
       * @stable 4.4
       */
      virtual UnicodeString& format(const StringPiece &number,
                                    UnicodeString& appendTo,
                                    FieldPositionIterator* posIter,
                                    UErrorCode& status) const;
  
  
      /**
       * Format a decimal number.
       * The number is a DigitList wrapper onto a floating point decimal number.
       * The default implementation in NumberFormat converts the decimal number
       * to a double and formats that.
       *
       * @param number    The number, a DigitList format Decimal Floating Point.
       * @param appendTo  Output parameter to receive result.
       *                  Result is appended to existing contents.
       * @param posIter   On return, can be used to iterate over positions
       *                  of fields generated by this format call.
       * @param status    Output param filled with success/failure status.
       * @return          Reference to 'appendTo' parameter.
       * @internal
       */
      virtual UnicodeString& format(const DigitList &number,
                                    UnicodeString& appendTo,
                                    FieldPositionIterator* posIter,
                                    UErrorCode& status) const;
  
      /**
       * Format a decimal number.
       * The number is a DigitList wrapper onto a floating point decimal number.
       * The default implementation in NumberFormat converts the decimal number
       * to a double and formats that.
       *
       * @param number    The number, a DigitList format Decimal Floating Point.
       * @param appendTo  Output parameter to receive result.
       *                  Result is appended to existing contents.
       * @param pos       On input: an alignment field, if desired.
       *                  On output: the offsets of the alignment field.
       * @param status    Output param filled with success/failure status.
       * @return          Reference to 'appendTo' parameter.
       * @internal
       */
      virtual UnicodeString& format(const DigitList &number,
                                    UnicodeString& appendTo,
                                    FieldPosition& pos,
                                    UErrorCode& status) const;
  
     using NumberFormat::parse;
  
     /**
      * Parse the given string using this object's choices. The method
      * does string comparisons to try to find an optimal match.
      * If no object can be parsed, index is unchanged, and NULL is
      * returned.  The result is returned as the most parsimonious
      * type of Formattable that will accomodate all of the
      * necessary precision.  For example, if the result is exactly 12,
      * it will be returned as a long.  However, if it is 1.5, it will
      * be returned as a double.
      *
      * @param text           The text to be parsed.
      * @param result         Formattable to be set to the parse result.
      *                       If parse fails, return contents are undefined.
      * @param parsePosition  The position to start parsing at on input.
      *                       On output, moved to after the last successfully
      *                       parse character. On parse failure, does not change.
      * @see Formattable
      * @stable ICU 2.0
      */
      virtual void parse(const UnicodeString& text,
                         Formattable& result,
                         ParsePosition& parsePosition) const;
  
      /**
       * Parses text from the given string as a currency amount.  Unlike
       * the parse() method, this method will attempt to parse a generic
       * currency name, searching for a match of this object's locale's
       * currency display names, or for a 3-letter ISO currency code.
       * This method will fail if this format is not a currency format,
       * that is, if it does not contain the currency pattern symbol
       * (U+00A4) in its prefix or suffix.
       *
       * @param text the string to parse
       * @param pos  input-output position; on input, the position within text
       *             to match; must have 0 <= pos.getIndex() < text.length();
       *             on output, the position after the last matched character.
       *             If the parse fails, the position in unchanged upon output.
       * @return     if parse succeeds, a pointer to a newly-created CurrencyAmount
       *             object (owned by the caller) containing information about
       *             the parsed currency; if parse fails, this is NULL.
       * @stable ICU 49
       */
      virtual CurrencyAmount* parseCurrency(const UnicodeString& text,
                                            ParsePosition& pos) const;
  
      /**
       * Returns the decimal format symbols, which is generally not changed
       * by the programmer or user.
       * @return desired DecimalFormatSymbols
       * @see DecimalFormatSymbols
       * @stable ICU 2.0
       */
      virtual const DecimalFormatSymbols* getDecimalFormatSymbols(void) const;
  
      /**
       * Sets the decimal format symbols, which is generally not changed
       * by the programmer or user.
       * @param symbolsToAdopt DecimalFormatSymbols to be adopted.
       * @stable ICU 2.0
       */
      virtual void adoptDecimalFormatSymbols(DecimalFormatSymbols* symbolsToAdopt);
  
      /**
       * Sets the decimal format symbols, which is generally not changed
       * by the programmer or user.
       * @param symbols DecimalFormatSymbols.
       * @stable ICU 2.0
       */
      virtual void setDecimalFormatSymbols(const DecimalFormatSymbols& symbols);
  
  
      /**
       * Returns the currency plural format information,
       * which is generally not changed by the programmer or user.
       * @return desired CurrencyPluralInfo
       * @stable ICU 4.2
       */
      virtual const CurrencyPluralInfo* getCurrencyPluralInfo(void) const;
  
      /**
       * Sets the currency plural format information,
       * which is generally not changed by the programmer or user.
       * @param toAdopt CurrencyPluralInfo to be adopted.
       * @stable ICU 4.2
       */
      virtual void adoptCurrencyPluralInfo(CurrencyPluralInfo* toAdopt);
  
      /**
       * Sets the currency plural format information,
       * which is generally not changed by the programmer or user.
       * @param info Currency Plural Info.
       * @stable ICU 4.2
       */
      virtual void setCurrencyPluralInfo(const CurrencyPluralInfo& info);
  
  
      /**
       * Get the positive prefix.
       *
       * @param result    Output param which will receive the positive prefix.
       * @return          A reference to 'result'.
       * Examples: +123, $123, sFr123
       * @stable ICU 2.0
       */
      UnicodeString& getPositivePrefix(UnicodeString& result) const;
  
      /**
       * Set the positive prefix.
       *
       * @param newValue    the new value of the the positive prefix to be set.
       * Examples: +123, $123, sFr123
       * @stable ICU 2.0
       */
      virtual void setPositivePrefix(const UnicodeString& newValue);
  
      /**
       * Get the negative prefix.
       *
       * @param result    Output param which will receive the negative prefix.
       * @return          A reference to 'result'.
       * Examples: -123, ($123) (with negative suffix), sFr-123
       * @stable ICU 2.0
       */
      UnicodeString& getNegativePrefix(UnicodeString& result) const;
  
      /**
       * Set the negative prefix.
       *
       * @param newValue    the new value of the the negative prefix to be set.
       * Examples: -123, ($123) (with negative suffix), sFr-123
       * @stable ICU 2.0
       */
      virtual void setNegativePrefix(const UnicodeString& newValue);
  
      /**
       * Get the positive suffix.
       *
       * @param result    Output param which will receive the positive suffix.
       * @return          A reference to 'result'.
       * Example: 123%
       * @stable ICU 2.0
       */
      UnicodeString& getPositiveSuffix(UnicodeString& result) const;
  
      /**
       * Set the positive suffix.
       *
       * @param newValue    the new value of the positive suffix to be set.
       * Example: 123%
       * @stable ICU 2.0
       */
      virtual void setPositiveSuffix(const UnicodeString& newValue);
  
      /**
       * Get the negative suffix.
       *
       * @param result    Output param which will receive the negative suffix.
       * @return          A reference to 'result'.
       * Examples: -123%, ($123) (with positive suffixes)
       * @stable ICU 2.0
       */
      UnicodeString& getNegativeSuffix(UnicodeString& result) const;
  
      /**
       * Set the negative suffix.
       *
       * @param newValue    the new value of the negative suffix to be set.
       * Examples: 123%
       * @stable ICU 2.0
       */
      virtual void setNegativeSuffix(const UnicodeString& newValue);
  
      /**
       * Get the multiplier for use in percent, permill, etc.
       * For a percentage, set the suffixes to have "%" and the multiplier to be 100.
       * (For Arabic, use arabic percent symbol).
       * For a permill, set the suffixes to have "\\u2031" and the multiplier to be 1000.
       *
       * @return    the multiplier for use in percent, permill, etc.
       * Examples: with 100, 1.23 -> "123", and "123" -> 1.23
       * @stable ICU 2.0
       */
      int32_t getMultiplier(void) const;
  
      /**
       * Set the multiplier for use in percent, permill, etc.
       * For a percentage, set the suffixes to have "%" and the multiplier to be 100.
       * (For Arabic, use arabic percent symbol).
       * For a permill, set the suffixes to have "\\u2031" and the multiplier to be 1000.
       *
       * @param newValue    the new value of the multiplier for use in percent, permill, etc.
       * Examples: with 100, 1.23 -> "123", and "123" -> 1.23
       * @stable ICU 2.0
       */
      virtual void setMultiplier(int32_t newValue);
  
      /**
       * Get the rounding increment.
       * @return A positive rounding increment, or 0.0 if a custom rounding
       * increment is not in effect.
       * @see #setRoundingIncrement
       * @see #getRoundingMode
       * @see #setRoundingMode
       * @stable ICU 2.0
       */
      virtual double getRoundingIncrement(void) const;
  
      /**
       * Set the rounding increment.  In the absence of a rounding increment,
       *    numbers will be rounded to the number of digits displayed.
       * @param newValue A positive rounding increment, or 0.0 to
       * use the default rounding increment.
       * Negative increments are equivalent to 0.0.
       * @see #getRoundingIncrement
       * @see #getRoundingMode
       * @see #setRoundingMode
       * @stable ICU 2.0
       */
      virtual void setRoundingIncrement(double newValue);
  
      /**
       * Get the rounding mode.
       * @return A rounding mode
       * @see #setRoundingIncrement
       * @see #getRoundingIncrement
       * @see #setRoundingMode
       * @stable ICU 2.0
       */
      virtual ERoundingMode getRoundingMode(void) const;
  
      /**
       * Set the rounding mode.
       * @param roundingMode A rounding mode
       * @see #setRoundingIncrement
       * @see #getRoundingIncrement
       * @see #getRoundingMode
       * @stable ICU 2.0
       */
      virtual void setRoundingMode(ERoundingMode roundingMode);
  
      /**
       * Get the width to which the output of format() is padded.
       * The width is counted in 16-bit code units.
       * @return the format width, or zero if no padding is in effect
       * @see #setFormatWidth
       * @see #getPadCharacterString
       * @see #setPadCharacter
       * @see #getPadPosition
       * @see #setPadPosition
       * @stable ICU 2.0
       */
      virtual int32_t getFormatWidth(void) const;
  
      /**
       * Set the width to which the output of format() is padded.
       * The width is counted in 16-bit code units.
       * This method also controls whether padding is enabled.
       * @param width the width to which to pad the result of
       * format(), or zero to disable padding.  A negative
       * width is equivalent to 0.
       * @see #getFormatWidth
       * @see #getPadCharacterString
       * @see #setPadCharacter
       * @see #getPadPosition
       * @see #setPadPosition
       * @stable ICU 2.0
       */
      virtual void setFormatWidth(int32_t width);
  
      /**
       * Get the pad character used to pad to the format width.  The
       * default is ' '.
       * @return a string containing the pad character. This will always
       * have a length of one 32-bit code point.
       * @see #setFormatWidth
       * @see #getFormatWidth
       * @see #setPadCharacter
       * @see #getPadPosition
       * @see #setPadPosition
       * @stable ICU 2.0
       */
      virtual UnicodeString getPadCharacterString() const;
  
      /**
       * Set the character used to pad to the format width.  If padding
       * is not enabled, then this will take effect if padding is later
       * enabled.
       * @param padChar a string containing the pad charcter. If the string
       * has length 0, then the pad characer is set to ' '.  Otherwise
       * padChar.char32At(0) will be used as the pad character.
       * @see #setFormatWidth
       * @see #getFormatWidth
       * @see #getPadCharacterString
       * @see #getPadPosition
       * @see #setPadPosition
       * @stable ICU 2.0
       */
      virtual void setPadCharacter(const UnicodeString &padChar);
  
      /**
       * Get the position at which padding will take place.  This is the location
       * at which padding will be inserted if the result of format()
       * is shorter than the format width.
       * @return the pad position, one of kPadBeforePrefix,
       * kPadAfterPrefix, kPadBeforeSuffix, or
       * kPadAfterSuffix.
       * @see #setFormatWidth
       * @see #getFormatWidth
       * @see #setPadCharacter
       * @see #getPadCharacterString
       * @see #setPadPosition
       * @see #EPadPosition
       * @stable ICU 2.0
       */
      virtual EPadPosition getPadPosition(void) const;
  
      /**
       * Set the position at which padding will take place.  This is the location
       * at which padding will be inserted if the result of format()
       * is shorter than the format width.  This has no effect unless padding is
       * enabled.
       * @param padPos the pad position, one of kPadBeforePrefix,
       * kPadAfterPrefix, kPadBeforeSuffix, or
       * kPadAfterSuffix.
       * @see #setFormatWidth
       * @see #getFormatWidth
       * @see #setPadCharacter
       * @see #getPadCharacterString
       * @see #getPadPosition
       * @see #EPadPosition
       * @stable ICU 2.0
       */
      virtual void setPadPosition(EPadPosition padPos);
  
      /**
       * Return whether or not scientific notation is used.
       * @return TRUE if this object formats and parses scientific notation
       * @see #setScientificNotation
       * @see #getMinimumExponentDigits
       * @see #setMinimumExponentDigits
       * @see #isExponentSignAlwaysShown
       * @see #setExponentSignAlwaysShown
       * @stable ICU 2.0
       */
      virtual UBool isScientificNotation(void) const;
  
      /**
       * Set whether or not scientific notation is used. When scientific notation
       * is used, the effective maximum number of integer digits is <= 8.  If the
       * maximum number of integer digits is set to more than 8, the effective
       * maximum will be 1.  This allows this call to generate a 'default' scientific
       * number format without additional changes.
       * @param useScientific TRUE if this object formats and parses scientific
       * notation
       * @see #isScientificNotation
       * @see #getMinimumExponentDigits
       * @see #setMinimumExponentDigits
       * @see #isExponentSignAlwaysShown
       * @see #setExponentSignAlwaysShown
       * @stable ICU 2.0
       */
      virtual void setScientificNotation(UBool useScientific);
  
      /**
       * Return the minimum exponent digits that will be shown.
       * @return the minimum exponent digits that will be shown
       * @see #setScientificNotation
       * @see #isScientificNotation
       * @see #setMinimumExponentDigits
       * @see #isExponentSignAlwaysShown
       * @see #setExponentSignAlwaysShown
       * @stable ICU 2.0
       */
      virtual int8_t getMinimumExponentDigits(void) const;
  
      /**
       * Set the minimum exponent digits that will be shown.  This has no
       * effect unless scientific notation is in use.
       * @param minExpDig a value >= 1 indicating the fewest exponent digits
       * that will be shown.  Values less than 1 will be treated as 1.
       * @see #setScientificNotation
       * @see #isScientificNotation
       * @see #getMinimumExponentDigits
       * @see #isExponentSignAlwaysShown
       * @see #setExponentSignAlwaysShown
       * @stable ICU 2.0
       */
      virtual void setMinimumExponentDigits(int8_t minExpDig);
  
      /**
       * Return whether the exponent sign is always shown.
       * @return TRUE if the exponent is always prefixed with either the
       * localized minus sign or the localized plus sign, false if only negative
       * exponents are prefixed with the localized minus sign.
       * @see #setScientificNotation
       * @see #isScientificNotation
       * @see #setMinimumExponentDigits
       * @see #getMinimumExponentDigits
       * @see #setExponentSignAlwaysShown
       * @stable ICU 2.0
       */
      virtual UBool isExponentSignAlwaysShown(void) const;
  
      /**
       * Set whether the exponent sign is always shown.  This has no effect
       * unless scientific notation is in use.
       * @param expSignAlways TRUE if the exponent is always prefixed with either
       * the localized minus sign or the localized plus sign, false if only
       * negative exponents are prefixed with the localized minus sign.
       * @see #setScientificNotation
       * @see #isScientificNotation
       * @see #setMinimumExponentDigits
       * @see #getMinimumExponentDigits
       * @see #isExponentSignAlwaysShown
       * @stable ICU 2.0
       */
      virtual void setExponentSignAlwaysShown(UBool expSignAlways);
  
      /**
       * Return the grouping size. Grouping size is the number of digits between
       * grouping separators in the integer portion of a number.  For example,
       * in the number "123,456.78", the grouping size is 3.
       *
       * @return    the grouping size.
       * @see setGroupingSize
       * @see NumberFormat::isGroupingUsed
       * @see DecimalFormatSymbols::getGroupingSeparator
       * @stable ICU 2.0
       */
      int32_t getGroupingSize(void) const;
  
      /**
       * Set the grouping size. Grouping size is the number of digits between
       * grouping separators in the integer portion of a number.  For example,
       * in the number "123,456.78", the grouping size is 3.
       *
       * @param newValue    the new value of the grouping size.
       * @see getGroupingSize
       * @see NumberFormat::setGroupingUsed
       * @see DecimalFormatSymbols::setGroupingSeparator
       * @stable ICU 2.0
       */
      virtual void setGroupingSize(int32_t newValue);
  
      /**
       * Return the secondary grouping size. In some locales one
       * grouping interval is used for the least significant integer
       * digits (the primary grouping size), and another is used for all
       * others (the secondary grouping size).  A formatter supporting a
       * secondary grouping size will return a positive integer unequal
       * to the primary grouping size returned by
       * getGroupingSize().  For example, if the primary
       * grouping size is 4, and the secondary grouping size is 2, then
       * the number 123456789 formats as "1,23,45,6789", and the pattern
       * appears as "#,##,###0".
       * @return the secondary grouping size, or a value less than
       * one if there is none
       * @see setSecondaryGroupingSize
       * @see NumberFormat::isGroupingUsed
       * @see DecimalFormatSymbols::getGroupingSeparator
       * @stable ICU 2.4
       */
      int32_t getSecondaryGroupingSize(void) const;
  
      /**
       * Set the secondary grouping size. If set to a value less than 1,
       * then secondary grouping is turned off, and the primary grouping
       * size is used for all intervals, not just the least significant.
       *
       * @param newValue    the new value of the secondary grouping size.
       * @see getSecondaryGroupingSize
       * @see NumberFormat#setGroupingUsed
       * @see DecimalFormatSymbols::setGroupingSeparator
       * @stable ICU 2.4
       */
      virtual void setSecondaryGroupingSize(int32_t newValue);
  
      /**
       * Allows you to get the behavior of the decimal separator with integers.
       * (The decimal separator will always appear with decimals.)
       *
       * @return    TRUE if the decimal separator always appear with decimals.
       * Example: Decimal ON: 12345 -> 12345.; OFF: 12345 -> 12345
       * @stable ICU 2.0
       */
      UBool isDecimalSeparatorAlwaysShown(void) const;
  
      /**
       * Allows you to set the behavior of the decimal separator with integers.
       * (The decimal separator will always appear with decimals.)
       *
       * @param newValue    set TRUE if the decimal separator will always appear with decimals.
       * Example: Decimal ON: 12345 -> 12345.; OFF: 12345 -> 12345
       * @stable ICU 2.0
       */
      virtual void setDecimalSeparatorAlwaysShown(UBool newValue);
  
      /**
       * Synthesizes a pattern string that represents the current state
       * of this Format object.
       *
       * @param result    Output param which will receive the pattern.
       *                  Previous contents are deleted.
       * @return          A reference to 'result'.
       * @see applyPattern
       * @stable ICU 2.0
       */
      virtual UnicodeString& toPattern(UnicodeString& result) const;
  
      /**
       * Synthesizes a localized pattern string that represents the current
       * state of this Format object.
       *
       * @param result    Output param which will receive the localized pattern.
       *                  Previous contents are deleted.
       * @return          A reference to 'result'.
       * @see applyPattern
       * @stable ICU 2.0
       */
      virtual UnicodeString& toLocalizedPattern(UnicodeString& result) const;
  
      /**
       * Apply the given pattern to this Format object.  A pattern is a
       * short-hand specification for the various formatting properties.
       * These properties can also be changed individually through the
       * various setter methods.
       * <P>
       * There is no limit to integer digits are set
       * by this routine, since that is the typical end-user desire;
       * use setMaximumInteger if you want to set a real value.
       * For negative numbers, use a second pattern, separated by a semicolon
       * <pre>
       * .      Example "#,#00.0#" -> 1,234.56
       * </pre>
       * This means a minimum of 2 integer digits, 1 fraction digit, and
       * a maximum of 2 fraction digits.
       * <pre>
       * .      Example: "#,#00.0#;(#,#00.0#)" for negatives in parantheses.
       * </pre>
       * In negative patterns, the minimum and maximum counts are ignored;
       * these are presumed to be set in the positive pattern.
       *
       * @param pattern    The pattern to be applied.
       * @param parseError Struct to recieve information on position
       *                   of error if an error is encountered
       * @param status     Output param set to success/failure code on
       *                   exit. If the pattern is invalid, this will be
       *                   set to a failure result.
       * @stable ICU 2.0
       */
      virtual void applyPattern(const UnicodeString& pattern,
                               UParseError& parseError,
                               UErrorCode& status);
      /**
       * Sets the pattern.
       * @param pattern   The pattern to be applied.
       * @param status    Output param set to success/failure code on
       *                  exit. If the pattern is invalid, this will be
       *                  set to a failure result.
       * @stable ICU 2.0
       */
      virtual void applyPattern(const UnicodeString& pattern,
                               UErrorCode& status);
  
      /**
       * Apply the given pattern to this Format object.  The pattern
       * is assumed to be in a localized notation. A pattern is a
       * short-hand specification for the various formatting properties.
       * These properties can also be changed individually through the
       * various setter methods.
       * <P>
       * There is no limit to integer digits are set
       * by this routine, since that is the typical end-user desire;
       * use setMaximumInteger if you want to set a real value.
       * For negative numbers, use a second pattern, separated by a semicolon
       * <pre>
       * .      Example "#,#00.0#" -> 1,234.56
       * </pre>
       * This means a minimum of 2 integer digits, 1 fraction digit, and
       * a maximum of 2 fraction digits.
       *
       * Example: "#,#00.0#;(#,#00.0#)" for negatives in parantheses.
       *
       * In negative patterns, the minimum and maximum counts are ignored;
       * these are presumed to be set in the positive pattern.
       *
       * @param pattern   The localized pattern to be applied.
       * @param parseError Struct to recieve information on position
       *                   of error if an error is encountered
       * @param status    Output param set to success/failure code on
       *                  exit. If the pattern is invalid, this will be
       *                  set to a failure result.
       * @stable ICU 2.0
       */
      virtual void applyLocalizedPattern(const UnicodeString& pattern,
                                         UParseError& parseError,
                                         UErrorCode& status);
  
      /**
       * Apply the given pattern to this Format object.
       *
       * @param pattern   The localized pattern to be applied.
       * @param status    Output param set to success/failure code on
       *                  exit. If the pattern is invalid, this will be
       *                  set to a failure result.
       * @stable ICU 2.0
       */
      virtual void applyLocalizedPattern(const UnicodeString& pattern,
                                         UErrorCode& status);
  
  
      /**
       * Sets the maximum number of digits allowed in the integer portion of a
       * number. This override limits the integer digit count to 309.
       *
       * @param newValue    the new value of the maximum number of digits
       *                      allowed in the integer portion of a number.
       * @see NumberFormat#setMaximumIntegerDigits
       * @stable ICU 2.0
       */
      virtual void setMaximumIntegerDigits(int32_t newValue);
  
      /**
       * Sets the minimum number of digits allowed in the integer portion of a
       * number. This override limits the integer digit count to 309.
       *
       * @param newValue    the new value of the minimum number of digits
       *                      allowed in the integer portion of a number.
       * @see NumberFormat#setMinimumIntegerDigits
       * @stable ICU 2.0
       */
      virtual void setMinimumIntegerDigits(int32_t newValue);
  
      /**
       * Sets the maximum number of digits allowed in the fraction portion of a
       * number. This override limits the fraction digit count to 340.
       *
       * @param newValue    the new value of the maximum number of digits
       *                    allowed in the fraction portion of a number.
       * @see NumberFormat#setMaximumFractionDigits
       * @stable ICU 2.0
       */
      virtual void setMaximumFractionDigits(int32_t newValue);
  
      /**
       * Sets the minimum number of digits allowed in the fraction portion of a
       * number. This override limits the fraction digit count to 340.
       *
       * @param newValue    the new value of the minimum number of digits
       *                    allowed in the fraction portion of a number.
       * @see NumberFormat#setMinimumFractionDigits
       * @stable ICU 2.0
       */
      virtual void setMinimumFractionDigits(int32_t newValue);
  
      /**
       * Returns the minimum number of significant digits that will be
       * displayed. This value has no effect unless areSignificantDigitsUsed()
       * returns true.
       * @return the fewest significant digits that will be shown
       * @stable ICU 3.0
       */
      int32_t getMinimumSignificantDigits() const;
  
      /**
       * Returns the maximum number of significant digits that will be
       * displayed. This value has no effect unless areSignificantDigitsUsed()
       * returns true.
       * @return the most significant digits that will be shown
       * @stable ICU 3.0
       */
      int32_t getMaximumSignificantDigits() const;
  
      /**
       * Sets the minimum number of significant digits that will be
       * displayed.  If <code>min</code> is less than one then it is set
       * to one.  If the maximum significant digits count is less than
       * <code>min</code>, then it is set to <code>min</code>.
       * This function also enables the use of significant digits
       * by this formatter - areSignificantDigitsUsed() will return TRUE.
       * @see #areSignificantDigitsUsed
       * @param min the fewest significant digits to be shown
       * @stable ICU 3.0
       */
      void setMinimumSignificantDigits(int32_t min);
  
      /**
       * Sets the maximum number of significant digits that will be
       * displayed.  If <code>max</code> is less than one then it is set
       * to one.  If the minimum significant digits count is greater
       * than <code>max</code>, then it is set to <code>max</code>.
       * This function also enables the use of significant digits
       * by this formatter - areSignificantDigitsUsed() will return TRUE.
       * @see #areSignificantDigitsUsed
       * @param max the most significant digits to be shown
       * @stable ICU 3.0
       */
      void setMaximumSignificantDigits(int32_t max);
  
      /**
       * Returns true if significant digits are in use, or false if
       * integer and fraction digit counts are in use.
       * @return true if significant digits are in use
       * @stable ICU 3.0
       */
      UBool areSignificantDigitsUsed() const;
  
      /**
       * Sets whether significant digits are in use, or integer and
       * fraction digit counts are in use.
       * @param useSignificantDigits true to use significant digits, or
       * false to use integer and fraction digit counts
       * @stable ICU 3.0
       */
      void setSignificantDigitsUsed(UBool useSignificantDigits);
  
   public:
      /**
       * Sets the currency used to display currency
       * amounts.  This takes effect immediately, if this format is a
       * currency format.  If this format is not a currency format, then
       * the currency is used if and when this object becomes a
       * currency format through the application of a new pattern.
       * @param theCurrency a 3-letter ISO code indicating new currency
       * to use.  It need not be null-terminated.  May be the empty
       * string or NULL to indicate no currency.
       * @param ec input-output error code
       * @stable ICU 3.0
       */
      virtual void setCurrency(const UChar* theCurrency, UErrorCode& ec);
  
      /**
       * Sets the currency used to display currency amounts.  See
       * setCurrency(const UChar*, UErrorCode&).
       * @deprecated ICU 3.0. Use setCurrency(const UChar*, UErrorCode&).
       */
      virtual void setCurrency(const UChar* theCurrency);
  
      /**
       * The resource tags we use to retrieve decimal format data from
       * locale resource bundles.
       * @deprecated ICU 3.4. This string has no public purpose. Please don't use it.
       */
      static const char fgNumberPatterns[];
  
  #ifndef U_HIDE_INTERNAL_API
      /**
       *  Get a FixedDecimal corresponding to a double as it would be
       *  formatted by this DecimalFormat.
       *  Internal, not intended for public use.
       *  @internal
       */
       FixedDecimal getFixedDecimal(double number, UErrorCode &status) const;
  
      /**
       *  Get a FixedDecimal corresponding to a formattable as it would be
       *  formatted by this DecimalFormat.
       *  Internal, not intended for public use.
       *  @internal
       */
       FixedDecimal getFixedDecimal(const Formattable &number, UErrorCode &status) const;
  
      /**
       *  Get a FixedDecimal corresponding to a DigitList as it would be
       *  formatted by this DecimalFormat. Note: the DigitList may be modified.
       *  Internal, not intended for public use.
       *  @internal
       */
       FixedDecimal getFixedDecimal(DigitList &number, UErrorCode &status) const;
  #endif  /* U_HIDE_INTERNAL_API */
  
  public:
  
      /**
       * Return the class ID for this class.  This is useful only for
       * comparing to a return value from getDynamicClassID().  For example:
       * <pre>
       * .      Base* polymorphic_pointer = createPolymorphicObject();
       * .      if (polymorphic_pointer->getDynamicClassID() ==
       * .          Derived::getStaticClassID()) ...
       * </pre>
       * @return          The class ID for all objects of this class.
       * @stable ICU 2.0
       */
      static UClassID U_EXPORT2 getStaticClassID(void);
  
      /**
       * Returns a unique class ID POLYMORPHICALLY.  Pure virtual override.
       * This method is to implement a simple version of RTTI, since not all
       * C++ compilers support genuine RTTI.  Polymorphic operator==() and
       * clone() methods call this method.
       *
       * @return          The class ID for this object. All objects of a
       *                  given class have the same class ID.  Objects of
       *                  other classes have different class IDs.
       * @stable ICU 2.0
       */
      virtual UClassID getDynamicClassID(void) const;
  
  private:
  
      DecimalFormat(); // default constructor not implemented
  
      int32_t precision() const;
  
      /**
       *   Initialize all fields of a new DecimalFormatter to a safe default value.
       *      Common code for use by constructors.
       */
      void init();
  
      /**
       * Do real work of constructing a new DecimalFormat.
       */
      void construct(UErrorCode&              status,
                     UParseError&             parseErr,
                     const UnicodeString*     pattern = 0,
                     DecimalFormatSymbols*    symbolsToAdopt = 0
                     );
  
      /**
       * Does the real work of generating a pattern.
       *
       * @param result     Output param which will receive the pattern.
       *                   Previous contents are deleted.
       * @param localized  TRUE return localized pattern.
       * @return           A reference to 'result'.
       */
      UnicodeString& toPattern(UnicodeString& result, UBool localized) const;
  
      /**
       * Does the real work of applying a pattern.
       * @param pattern    The pattern to be applied.
       * @param localized  If true, the pattern is localized; else false.
       * @param parseError Struct to recieve information on position
       *                   of error if an error is encountered
       * @param status     Output param set to success/failure code on
       *                   exit. If the pattern is invalid, this will be
       *                   set to a failure result.
       */
      void applyPattern(const UnicodeString& pattern,
                              UBool localized,
                              UParseError& parseError,
                              UErrorCode& status);
  
      /*
       * similar to applyPattern, but without re-gen affix for currency
       */
      void applyPatternInternally(const UnicodeString& pluralCount,
                                  const UnicodeString& pattern,
                                  UBool localized,
                                  UParseError& parseError,
                                  UErrorCode& status);
  
      /*
       * only apply pattern without expand affixes
       */
      void applyPatternWithoutExpandAffix(const UnicodeString& pattern,
                                          UBool localized,
                                          UParseError& parseError,
                                          UErrorCode& status);
  
  
      /*
       * expand affixes (after apply patter) and re-compute fFormatWidth
       */
      void expandAffixAdjustWidth(const UnicodeString* pluralCount);
  
  
      /**
       * Do the work of formatting a number, either a double or a long.
       *
       * @param appendTo       Output parameter to receive result.
       *                       Result is appended to existing contents.
       * @param handler        Records information about field positions.
       * @param digits         the digits to be formatted.
       * @param isInteger      if TRUE format the digits as Integer.
       * @return               Reference to 'appendTo' parameter.
       */
      UnicodeString& subformat(UnicodeString& appendTo,
                               FieldPositionHandler& handler,
                               DigitList&     digits,
                               UBool          isInteger,
                               UErrorCode &status) const;
  
  
      void parse(const UnicodeString& text,
                 Formattable& result,
                 ParsePosition& pos,
                 UChar* currency) const;
  
      enum {
          fgStatusInfinite,
          fgStatusLength      // Leave last in list.
      } StatusFlags;
  
      UBool subparse(const UnicodeString& text,
                     const UnicodeString* negPrefix,
                     const UnicodeString* negSuffix,
                     const UnicodeString* posPrefix,
                     const UnicodeString* posSuffix,
                     UBool complexCurrencyParsing,
                     int8_t type,
                     ParsePosition& parsePosition,
                     DigitList& digits, UBool* status,
                     UChar* currency) const;
  
      // Mixed style parsing for currency.
      // It parses against the current currency pattern
      // using complex affix comparison
      // parses against the currency plural patterns using complex affix comparison,
      // and parses against the current pattern using simple affix comparison.
      UBool parseForCurrency(const UnicodeString& text,
                             ParsePosition& parsePosition,
                             DigitList& digits,
                             UBool* status,
                             UChar* currency) const;
  
      int32_t skipPadding(const UnicodeString& text, int32_t position) const;
  
      int32_t compareAffix(const UnicodeString& input,
                           int32_t pos,
                           UBool isNegative,
                           UBool isPrefix,
                           const UnicodeString* affixPat,
                           UBool complexCurrencyParsing,
                           int8_t type,
                           UChar* currency) const;
  
      static UnicodeString& trimMarksFromAffix(const UnicodeString& affix, UnicodeString& trimmedAffix);
  
      UBool equalWithSignCompatibility(UChar32 lhs, UChar32 rhs) const;
  
      int32_t compareSimpleAffix(const UnicodeString& affix,
                                        const UnicodeString& input,
                                        int32_t pos,
                                        UBool lenient) const;
  
      static int32_t skipPatternWhiteSpace(const UnicodeString& text, int32_t pos);
  
      static int32_t skipUWhiteSpace(const UnicodeString& text, int32_t pos);
  
      static int32_t skipUWhiteSpaceAndMarks(const UnicodeString& text, int32_t pos);
  
      static int32_t skipBidiMarks(const UnicodeString& text, int32_t pos);
  
      int32_t compareComplexAffix(const UnicodeString& affixPat,
                                  const UnicodeString& input,
                                  int32_t pos,
                                  int8_t type,
                                  UChar* currency) const;
  
      static int32_t match(const UnicodeString& text, int32_t pos, UChar32 ch);
  
      static int32_t match(const UnicodeString& text, int32_t pos, const UnicodeString& str);
  
      static UBool matchSymbol(const UnicodeString &text, int32_t position, int32_t length, const UnicodeString &symbol,
                               UnicodeSet *sset, UChar32 schar);
  
      static UBool matchDecimal(UChar32 symbolChar,
                              UBool sawDecimal,  UChar32 sawDecimalChar,
                               const UnicodeSet *sset, UChar32 schar);
  
      static UBool matchGrouping(UChar32 groupingChar,
                              UBool sawGrouping, UChar32 sawGroupingChar,
                               const UnicodeSet *sset,
                               UChar32 decimalChar, const UnicodeSet *decimalSet,
                               UChar32 schar);
  
      /**
       * Get a decimal format symbol.
       * Returns a const reference to the symbol string.
       * @internal
       */
      inline const UnicodeString &getConstSymbol(DecimalFormatSymbols::ENumberFormatSymbol symbol) const;
  
      int32_t appendAffix(UnicodeString& buf,
                          double number,
                          FieldPositionHandler& handler,
                          UBool isNegative,
                          UBool isPrefix) const;
  
      /**
       * Append an affix to the given UnicodeString, using quotes if
       * there are special characters.  Single quotes themselves must be
       * escaped in either case.
       */
      void appendAffixPattern(UnicodeString& appendTo, const UnicodeString& affix,
                              UBool localized) const;
  
      void appendAffixPattern(UnicodeString& appendTo,
                              const UnicodeString* affixPattern,
                              const UnicodeString& expAffix, UBool localized) const;
  
      void expandAffix(const UnicodeString& pattern,
                       UnicodeString& affix,
                       double number,
                       FieldPositionHandler& handler,
                       UBool doFormat,
                       const UnicodeString* pluralCount) const;
  
      void expandAffixes(const UnicodeString* pluralCount);
  
      void addPadding(UnicodeString& appendTo,
                      FieldPositionHandler& handler,
                      int32_t prefixLen, int32_t suffixLen) const;
  
      UBool isGroupingPosition(int32_t pos) const;
  
      void setCurrencyForSymbols();
  
      // similar to setCurrency without re-compute the affixes for currency.
      // If currency changes, the affix pattern for currency is not changed,
      // but the affix will be changed. So, affixes need to be
      // re-computed in setCurrency(), but not in setCurrencyInternally().
      virtual void setCurrencyInternally(const UChar* theCurrency, UErrorCode& ec);
  
      // set up currency affix patterns for mix parsing.
      // The patterns saved here are the affix patterns of default currency
      // pattern and the unique affix patterns of the plural currency patterns.
      // Those patterns are used by parseForCurrency().
      void setupCurrencyAffixPatterns(UErrorCode& status);
  
      // set up the currency affixes used in currency plural formatting.
      // It sets up both fAffixesForCurrency for currency pattern if the current
      // pattern contains 3 currency signs,
      // and it sets up fPluralAffixesForCurrency for currency plural patterns.
      void setupCurrencyAffixes(const UnicodeString& pattern,
                                UBool setupForCurrentPattern,
                                UBool setupForPluralPattern,
                                UErrorCode& status);
  
      // hashtable operations
      Hashtable* initHashForAffixPattern(UErrorCode& status);
      Hashtable* initHashForAffix(UErrorCode& status);
  
      void deleteHashForAffixPattern();
      void deleteHashForAffix(Hashtable*& table);
  
      void copyHashForAffixPattern(const Hashtable* source,
                                   Hashtable* target, UErrorCode& status);
      void copyHashForAffix(const Hashtable* source,
                            Hashtable* target, UErrorCode& status);
  
      UnicodeString& _format(int64_t number,
                             UnicodeString& appendTo,
                             FieldPositionHandler& handler,
                             UErrorCode &status) const;
      UnicodeString& _format(double number,
                             UnicodeString& appendTo,
                             FieldPositionHandler& handler,
                             UErrorCode &status) const;
      UnicodeString& _format(const DigitList &number,
                             UnicodeString& appendTo,
                             FieldPositionHandler& handler,
                             UErrorCode &status) const;
  
      /**
       * Constants.
       */
  
      UnicodeString           fPositivePrefix;
      UnicodeString           fPositiveSuffix;
      UnicodeString           fNegativePrefix;
      UnicodeString           fNegativeSuffix;
      UnicodeString*          fPosPrefixPattern;
      UnicodeString*          fPosSuffixPattern;
      UnicodeString*          fNegPrefixPattern;
      UnicodeString*          fNegSuffixPattern;
  
      /**
       * Formatter for ChoiceFormat-based currency names.  If this field
       * is not null, then delegate to it to format currency symbols.
       * @since ICU 2.6
       */
      ChoiceFormat*           fCurrencyChoice;
  
      DigitList *             fMultiplier;   // NULL for multiplier of one
      int32_t                 fScale;
      int32_t                 fGroupingSize;
      int32_t                 fGroupingSize2;
      UBool                   fDecimalSeparatorAlwaysShown;
      DecimalFormatSymbols*   fSymbols;
  
      UBool                   fUseSignificantDigits;
      int32_t                 fMinSignificantDigits;
      int32_t                 fMaxSignificantDigits;
  
      UBool                   fUseExponentialNotation;
      int8_t                  fMinExponentDigits;
      UBool                   fExponentSignAlwaysShown;
  
      EnumSet<UNumberFormatAttribute,
              UNUM_MAX_NONBOOLEAN_ATTRIBUTE+1,
              UNUM_LIMIT_BOOLEAN_ATTRIBUTE>
                              fBoolFlags;
  
      DigitList*              fRoundingIncrement;  // NULL if no rounding increment specified.
      ERoundingMode           fRoundingMode;
  
      UChar32                 fPad;
      int32_t                 fFormatWidth;
      EPadPosition            fPadPosition;
  
      /*
       * Following are used for currency format
       */
      // pattern used in this formatter
      UnicodeString fFormatPattern;
      // style is only valid when decimal formatter is constructed by
      // DecimalFormat(pattern, decimalFormatSymbol, style)
      int fStyle;
      /*
       * Represents whether this is a currency format, and which
       * currency format style.
       * 0: not currency format type;
       * 1: currency style -- symbol name, such as "$" for US dollar.
       * 2: currency style -- ISO name, such as USD for US dollar.
       * 3: currency style -- plural long name, such as "US Dollar" for
       *                      "1.00 US Dollar", or "US Dollars" for
       *                      "3.00 US Dollars".
       */
      int fCurrencySignCount;
  
  
      /* For currency parsing purose,
       * Need to remember all prefix patterns and suffix patterns of
       * every currency format pattern,
       * including the pattern of default currecny style
       * and plural currency style. And the patterns are set through applyPattern.
       */
      // TODO: innerclass?
      /* This is not needed in the class declaration, so it is moved into decimfmp.cpp
      struct AffixPatternsForCurrency : public UMemory {
          // negative prefix pattern
          UnicodeString negPrefixPatternForCurrency;
          // negative suffix pattern
          UnicodeString negSuffixPatternForCurrency;
          // positive prefix pattern
          UnicodeString posPrefixPatternForCurrency;
          // positive suffix pattern
          UnicodeString posSuffixPatternForCurrency;
          int8_t patternType;
  
          AffixPatternsForCurrency(const UnicodeString& negPrefix,
                                   const UnicodeString& negSuffix,
                                   const UnicodeString& posPrefix,
                                   const UnicodeString& posSuffix,
                                   int8_t type) {
              negPrefixPatternForCurrency = negPrefix;
              negSuffixPatternForCurrency = negSuffix;
              posPrefixPatternForCurrency = posPrefix;
              posSuffixPatternForCurrency = posSuffix;
              patternType = type;
          }
      };
      */
  
      /* affix for currency formatting when the currency sign in the pattern
       * equals to 3, such as the pattern contains 3 currency sign or
       * the formatter style is currency plural format style.
       */
      /* This is not needed in the class declaration, so it is moved into decimfmp.cpp
      struct AffixesForCurrency : public UMemory {
          // negative prefix
          UnicodeString negPrefixForCurrency;
          // negative suffix
          UnicodeString negSuffixForCurrency;
          // positive prefix
          UnicodeString posPrefixForCurrency;
          // positive suffix
          UnicodeString posSuffixForCurrency;
  
          int32_t formatWidth;
  
          AffixesForCurrency(const UnicodeString& negPrefix,
                             const UnicodeString& negSuffix,
                             const UnicodeString& posPrefix,
                             const UnicodeString& posSuffix) {
              negPrefixForCurrency = negPrefix;
              negSuffixForCurrency = negSuffix;
              posPrefixForCurrency = posPrefix;
              posSuffixForCurrency = posSuffix;
          }
      };
      */
  
      // Affix pattern set for currency.
      // It is a set of AffixPatternsForCurrency,
      // each element of the set saves the negative prefix pattern,
      // negative suffix pattern, positive prefix pattern,
      // and positive suffix  pattern of a pattern.
      // It is used for currency mixed style parsing.
      // It is actually is a set.
      // The set contains the default currency pattern from the locale,
      // and the currency plural patterns.
      // Since it is a set, it does not contain duplicated items.
      // For example, if 2 currency plural patterns are the same, only one pattern
      // is included in the set. When parsing, we do not check whether the plural
      // count match or not.
      Hashtable* fAffixPatternsForCurrency;
  
      // Following 2 are affixes for currency.
      // It is a hash map from plural count to AffixesForCurrency.
      // AffixesForCurrency saves the negative prefix,
      // negative suffix, positive prefix, and positive suffix of a pattern.
      // It is used during currency formatting only when the currency sign count
      // is 3. In which case, the affixes are getting from here, not
      // from the fNegativePrefix etc.
      Hashtable* fAffixesForCurrency;  // for current pattern
      Hashtable* fPluralAffixesForCurrency;  // for plural pattern
  
      // Information needed for DecimalFormat to format/parse currency plural.
      CurrencyPluralInfo* fCurrencyPluralInfo;
  
  #if UCONFIG_HAVE_PARSEALLINPUT
      UNumberFormatAttributeValue fParseAllInput;
  #endif
  
      // Decimal Format Static Sets singleton.
      const DecimalFormatStaticSets *fStaticSets;
  
  
  protected:
  
  #ifndef U_HIDE_INTERNAL_API
      /**
       * Rounds a value according to the rules of this object.
       * @internal
       */
      DigitList& _round(const DigitList& number, DigitList& adjustedNum, UBool& isNegative, UErrorCode& status) const;
  #endif  /* U_HIDE_INTERNAL_API */
  
      /**
       * Returns the currency in effect for this formatter.  Subclasses
       * should override this method as needed.  Unlike getCurrency(),
       * this method should never return "".
       * @result output parameter for null-terminated result, which must
       * have a capacity of at least 4
       * @internal
       */
      virtual void getEffectiveCurrency(UChar* result, UErrorCode& ec) const;
  
    /** number of integer digits
     * @stable ICU 2.4
     */
      static const int32_t  kDoubleIntegerDigits;
    /** number of fraction digits
     * @stable ICU 2.4
     */
      static const int32_t  kDoubleFractionDigits;
  
      /**
       * When someone turns on scientific mode, we assume that more than this
       * number of digits is due to flipping from some other mode that didn't
       * restrict the maximum, and so we force 1 integer digit.  We don't bother
       * to track and see if someone is using exponential notation with more than
       * this number, it wouldn't make sense anyway, and this is just to make sure
       * that someone turning on scientific mode with default settings doesn't
       * end up with lots of zeroes.
       * @stable ICU 2.8
       */
      static const int32_t  kMaxScientificIntegerDigits;
  
  #if UCONFIG_FORMAT_FASTPATHS_49
   private:
      /**
       * Internal state.
       * @internal
       */
      uint8_t fReserved[UNUM_DECIMALFORMAT_INTERNAL_SIZE];
  
  
      /**
       * Called whenever any state changes. Recomputes whether fastpath is OK to use.
       */
      void handleChanged();
  #endif
  };
  
  inline const UnicodeString &
  DecimalFormat::getConstSymbol(DecimalFormatSymbols::ENumberFormatSymbol symbol) const {
      return fSymbols->getConstSymbol(symbol);
  }
  
  U_NAMESPACE_END
  
  #endif /* #if !UCONFIG_NO_FORMATTING */
  
  #endif // _DECIMFMT
  //eof
  