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icu46/source/i18n/unicode/decimfmt.h

+/*
+********************************************************************************
+*   Copyright (C) 1997-2010, 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
+********************************************************************************
+*/
+
+#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"
+
+union UHashTok;
+
+U_NAMESPACE_BEGIN
+
+class DigitList;
+class ChoiceFormat;
+class CurrencyPluralInfo;
+class Hashtable;
+class FieldPositionHandler;
+
+/**
+ * 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 */
+        // We don't support ROUND_UNNECESSARY
+    };
+
+    /**
+     * 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);
+
+    /**
+     * 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, kNumberStyle etc.
+     * @param status            Output param set to success/failure code. If the
+     *                          pattern is invalid this will be set to a failure code.
+     * @internal ICU 4.2
+     */
+    DecimalFormat(  const UnicodeString& pattern,
+                    DecimalFormatSymbols* symbolsToAdopt,
+                    NumberFormat::EStyles style,
+                    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 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 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 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;
+
+
+    /**
+     * Format a Formattable using base-10 representation.
+     *
+     * @param obj       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    Error code indicating success or failure.
+     * @return          Reference to 'appendTo' parameter.
+     * @stable ICU 2.0
+     */
+    virtual UnicodeString& format(const Formattable& obj,
+                                  UnicodeString& appendTo,
+                                  FieldPosition& pos,
+                                  UErrorCode& status) const;
+
+    /**
+     * Redeclared NumberFormat method.
+     * Formats an object to produce a string.
+     *
+     * @param obj       The object to format.
+     * @param appendTo  Output parameter to receive result.
+     *                  Result is appended to existing contents.
+     * @param status    Output parameter filled in with success or failure status.
+     * @return          Reference to 'appendTo' parameter.
+     * @stable ICU 2.0
+     */
+    UnicodeString& format(const Formattable& obj,
+                          UnicodeString& appendTo,
+                          UErrorCode& status) const;
+
+    /**
+     * Redeclared NumberFormat method.
+     * Format a double number.
+     *
+     * @param number    The value to be formatted.
+     * @param appendTo  Output parameter to receive result.
+     *                  Result is appended to existing contents.
+     * @return          Reference to 'appendTo' parameter.
+     * @stable ICU 2.0
+     */
+    UnicodeString& format(double number,
+                          UnicodeString& appendTo) const;
+
+    /**
+     * Redeclared NumberFormat method.
+     * Format a long number. These methods call the NumberFormat
+     * pure virtual format() methods with the default FieldPosition.
+     *
+     * @param number    The value to be formatted.
+     * @param appendTo  Output parameter to receive result.
+     *                  Result is appended to existing contents.
+     * @return          Reference to 'appendTo' parameter.
+     * @stable ICU 2.0
+     */
+    UnicodeString& format(int32_t number,
+                          UnicodeString& appendTo) const;
+
+    /**
+     * Redeclared NumberFormat method.
+     * Format an int64 number. These methods call the NumberFormat
+     * pure virtual format() methods with the default FieldPosition.
+     *
+     * @param number    The value to be formatted.
+     * @param appendTo  Output parameter to receive result.
+     *                  Result is appended to existing contents.
+     * @return          Reference to 'appendTo' parameter.
+     * @stable ICU 2.8
+     */
+    UnicodeString& format(int64_t number,
+                          UnicodeString& appendTo) const;
+   /**
+    * 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;
+
+    // Declare here again to get rid of function hiding problems.
+    /**
+     * Parse the given string using this object's choices.
+     *
+     * @param text           The text to be parsed.
+     * @param result         Formattable to be set to the parse result.
+     * @param status    Output parameter filled in with success or failure status.
+     * @stable ICU 2.0
+     */
+    virtual void parse(const UnicodeString& text,
+                       Formattable& result,
+                       UErrorCode& status) 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 result output parameter to receive result. This will have
+     * its currency set to the parsed ISO currency code.
+     * @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 a reference to result
+     * @internal
+     */
+    virtual Formattable& parseCurrency(const UnicodeString& text,
+                                       Formattable& result,
+                                       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 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.
+     * 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);
+
+    /**
+     * 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);
+
+    /**
+     * 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
+     * value has no effect unless areSignificantDigits() returns true.
+     * @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 value has no effect unless areSignificantDigits() returns
+     * true.
+     * @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[];
+
+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.
+     *      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) const;
+
+
+    void parse(const UnicodeString& text,
+               Formattable& result,
+               ParsePosition& pos,
+               UBool parseCurrency) 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 currencyParsing,
+                   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 currencyParsing,
+                         int8_t type,
+                         UChar* currency) const;
+
+    static int32_t compareSimpleAffix(const UnicodeString& affix,
+                                      const UnicodeString& input,
+                                      int32_t pos);
+
+    static int32_t skipRuleWhiteSpace(const UnicodeString& text, int32_t pos);
+
+    static int32_t skipUWhiteSpace(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);
+
+    /**
+     * 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) const;
+    UnicodeString& _format(double number,
+                           UnicodeString& appendTo,
+                           FieldPositionHandler& handler) const;
+    UnicodeString& _format(const DigitList &number,
+                           UnicodeString& appendTo,
+                           FieldPositionHandler& handler,
+                           UErrorCode &status) const;
+
+    // currency sign count
+    enum {
+        fgCurrencySignCountZero,
+        fgCurrencySignCountInSymbolFormat,
+        fgCurrencySignCountInISOFormat,
+        fgCurrencySignCountInPluralFormat
+    } CurrencySignCount;
+
+    /**
+     * 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                 fGroupingSize;
+    int32_t                 fGroupingSize2;
+    UBool                   fDecimalSeparatorAlwaysShown;
+    DecimalFormatSymbols*   fSymbols;
+
+    UBool                   fUseSignificantDigits;
+    int32_t                 fMinSignificantDigits;
+    int32_t                 fMaxSignificantDigits;
+
+    UBool                   fUseExponentialNotation;
+    int8_t                  fMinExponentDigits;
+    UBool                   fExponentSignAlwaysShown;
+
+    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;
+
+protected:
+
+    /**
+     * 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;
+};
+
+inline UnicodeString&
+DecimalFormat::format(const Formattable& obj,
+                      UnicodeString& appendTo,
+                      UErrorCode& status) const {
+    // Don't use Format:: - use immediate base class only,
+    // in case immediate base modifies behavior later.
+    return NumberFormat::format(obj, appendTo, status);
+}
+
+inline UnicodeString&
+DecimalFormat::format(double number,
+                      UnicodeString& appendTo) const {
+    FieldPosition pos(0);
+    return format(number, appendTo, pos);
+}
+
+inline UnicodeString&
+DecimalFormat::format(int32_t number,
+                      UnicodeString& appendTo) const {
+    FieldPosition pos(0);
+    return format((int64_t)number, appendTo, pos);
+}
+
+inline const UnicodeString &
+DecimalFormat::getConstSymbol(DecimalFormatSymbols::ENumberFormatSymbol symbol) const {
+    return fSymbols->getConstSymbol(symbol);
+}
+
+U_NAMESPACE_END
+
+#endif /* #if !UCONFIG_NO_FORMATTING */
+
+#endif // _DECIMFMT
+//eof