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      1 /*
      2 ********************************************************************************
      3 *   Copyright (C) 1997-2015, International Business Machines
      4 *   Corporation and others.  All Rights Reserved.
      5 ********************************************************************************
      6 *
      7 * File DECIMFMT.H
      8 *
      9 * Modification History:
     10 *
     11 *   Date        Name        Description
     12 *   02/19/97    aliu        Converted from java.
     13 *   03/20/97    clhuang     Updated per C++ implementation.
     14 *   04/03/97    aliu        Rewrote parsing and formatting completely, and
     15 *                           cleaned up and debugged.  Actually works now.
     16 *   04/17/97    aliu        Changed DigitCount to int per code review.
     17 *   07/10/97    helena      Made ParsePosition a class and get rid of the function
     18 *                           hiding problems.
     19 *   09/09/97    aliu        Ported over support for exponential formats.
     20 *   07/20/98    stephen     Changed documentation
     21 *   01/30/13    emmons      Added Scaling methods
     22 ********************************************************************************
     23 */
     24 
     25 #ifndef DECIMFMT_H
     26 #define DECIMFMT_H
     27 
     28 #include "unicode/utypes.h"
     29 /**
     30  * \file
     31  * \brief C++ API: Formats decimal numbers.
     32  */
     33 
     34 #if !UCONFIG_NO_FORMATTING
     35 
     36 #include "unicode/dcfmtsym.h"
     37 #include "unicode/numfmt.h"
     38 #include "unicode/locid.h"
     39 #include "unicode/fpositer.h"
     40 #include "unicode/stringpiece.h"
     41 #include "unicode/curramt.h"
     42 #include "unicode/enumset.h"
     43 
     44 /**
     45  * \def UNUM_DECIMALFORMAT_INTERNAL_SIZE
     46  * @internal
     47  */
     48 #if UCONFIG_FORMAT_FASTPATHS_49
     49 #define UNUM_DECIMALFORMAT_INTERNAL_SIZE 16
     50 #endif
     51 
     52 U_NAMESPACE_BEGIN
     53 
     54 class DigitList;
     55 class ChoiceFormat;
     56 class CurrencyPluralInfo;
     57 class Hashtable;
     58 class UnicodeSet;
     59 class FieldPositionHandler;
     60 class DecimalFormatStaticSets;
     61 class FixedDecimal;
     62 
     63 // explicit template instantiation. see digitlst.h
     64 #if defined (_MSC_VER)
     65 template class U_I18N_API    EnumSet<UNumberFormatAttribute,
     66             UNUM_MAX_NONBOOLEAN_ATTRIBUTE+1,
     67             UNUM_LIMIT_BOOLEAN_ATTRIBUTE>;
     68 #endif
     69 
     70 /**
     71  * DecimalFormat is a concrete subclass of NumberFormat that formats decimal
     72  * numbers. It has a variety of features designed to make it possible to parse
     73  * and format numbers in any locale, including support for Western, Arabic, or
     74  * Indic digits.  It also supports different flavors of numbers, including
     75  * integers ("123"), fixed-point numbers ("123.4"), scientific notation
     76  * ("1.23E4"), percentages ("12%"), and currency amounts ("$123", "USD123",
     77  * "123 US dollars").  All of these flavors can be easily localized.
     78  *
     79  * <p>To obtain a NumberFormat for a specific locale (including the default
     80  * locale) call one of NumberFormat's factory methods such as
     81  * createInstance(). Do not call the DecimalFormat constructors directly, unless
     82  * you know what you are doing, since the NumberFormat factory methods may
     83  * return subclasses other than DecimalFormat.
     84  *
     85  * <p><strong>Example Usage</strong>
     86  *
     87  * \code
     88  *     // Normally we would have a GUI with a menu for this
     89  *     int32_t locCount;
     90  *     const Locale* locales = NumberFormat::getAvailableLocales(locCount);
     91  *
     92  *     double myNumber = -1234.56;
     93  *     UErrorCode success = U_ZERO_ERROR;
     94  *     NumberFormat* form;
     95  *
     96  *     // Print out a number with the localized number, currency and percent
     97  *     // format for each locale.
     98  *     UnicodeString countryName;
     99  *     UnicodeString displayName;
    100  *     UnicodeString str;
    101  *     UnicodeString pattern;
    102  *     Formattable fmtable;
    103  *     for (int32_t j = 0; j < 3; ++j) {
    104  *         cout << endl << "FORMAT " << j << endl;
    105  *         for (int32_t i = 0; i < locCount; ++i) {
    106  *             if (locales[i].getCountry(countryName).size() == 0) {
    107  *                 // skip language-only
    108  *                 continue;
    109  *             }
    110  *             switch (j) {
    111  *             case 0:
    112  *                 form = NumberFormat::createInstance(locales[i], success ); break;
    113  *             case 1:
    114  *                 form = NumberFormat::createCurrencyInstance(locales[i], success ); break;
    115  *             default:
    116  *                 form = NumberFormat::createPercentInstance(locales[i], success ); break;
    117  *             }
    118  *             if (form) {
    119  *                 str.remove();
    120  *                 pattern = ((DecimalFormat*)form)->toPattern(pattern);
    121  *                 cout << locales[i].getDisplayName(displayName) << ": " << pattern;
    122  *                 cout << "  ->  " << form->format(myNumber,str) << endl;
    123  *                 form->parse(form->format(myNumber,str), fmtable, success);
    124  *                 delete form;
    125  *             }
    126  *         }
    127  *     }
    128  * \endcode
    129  * <P>
    130  * Another example use createInstance(style)
    131  * <P>
    132  * <pre>
    133  * <strong>// Print out a number using the localized number, currency,
    134  * // percent, scientific, integer, iso currency, and plural currency
    135  * // format for each locale</strong>
    136  * Locale* locale = new Locale("en", "US");
    137  * double myNumber = 1234.56;
    138  * UErrorCode success = U_ZERO_ERROR;
    139  * UnicodeString str;
    140  * Formattable fmtable;
    141  * for (int j=NumberFormat::kNumberStyle;
    142  *      j<=NumberFormat::kPluralCurrencyStyle;
    143  *      ++j) {
    144  *     NumberFormat* format = NumberFormat::createInstance(locale, j, success);
    145  *     str.remove();
    146  *     cout << "format result " << form->format(myNumber, str) << endl;
    147  *     format->parse(form->format(myNumber, str), fmtable, success);
    148  * }</pre>
    149  *
    150  *
    151  * <p><strong>Patterns</strong>
    152  *
    153  * <p>A DecimalFormat consists of a <em>pattern</em> and a set of
    154  * <em>symbols</em>.  The pattern may be set directly using
    155  * applyPattern(), or indirectly using other API methods which
    156  * manipulate aspects of the pattern, such as the minimum number of integer
    157  * digits.  The symbols are stored in a DecimalFormatSymbols
    158  * object.  When using the NumberFormat factory methods, the
    159  * pattern and symbols are read from ICU's locale data.
    160  *
    161  * <p><strong>Special Pattern Characters</strong>
    162  *
    163  * <p>Many characters in a pattern are taken literally; they are matched during
    164  * parsing and output unchanged during formatting.  Special characters, on the
    165  * other hand, stand for other characters, strings, or classes of characters.
    166  * For example, the '#' character is replaced by a localized digit.  Often the
    167  * replacement character is the same as the pattern character; in the U.S. locale,
    168  * the ',' grouping character is replaced by ','.  However, the replacement is
    169  * still happening, and if the symbols are modified, the grouping character
    170  * changes.  Some special characters affect the behavior of the formatter by
    171  * their presence; for example, if the percent character is seen, then the
    172  * value is multiplied by 100 before being displayed.
    173  *
    174  * <p>To insert a special character in a pattern as a literal, that is, without
    175  * any special meaning, the character must be quoted.  There are some exceptions to
    176  * this which are noted below.
    177  *
    178  * <p>The characters listed here are used in non-localized patterns.  Localized
    179  * patterns use the corresponding characters taken from this formatter's
    180  * DecimalFormatSymbols object instead, and these characters lose
    181  * their special status.  Two exceptions are the currency sign and quote, which
    182  * are not localized.
    183  *
    184  * <table border=0 cellspacing=3 cellpadding=0>
    185  *   <tr bgcolor="#ccccff">
    186  *     <td align=left><strong>Symbol</strong>
    187  *     <td align=left><strong>Location</strong>
    188  *     <td align=left><strong>Localized?</strong>
    189  *     <td align=left><strong>Meaning</strong>
    190  *   <tr valign=top>
    191  *     <td><code>0</code>
    192  *     <td>Number
    193  *     <td>Yes
    194  *     <td>Digit
    195  *   <tr valign=top bgcolor="#eeeeff">
    196  *     <td><code>1-9</code>
    197  *     <td>Number
    198  *     <td>Yes
    199  *     <td>'1' through '9' indicate rounding.
    200  *   <tr valign=top>
    201  *     <td><code>\htmlonly&#x40;\endhtmlonly</code> <!--doxygen doesn't like @-->
    202  *     <td>Number
    203  *     <td>No
    204  *     <td>Significant digit
    205  *   <tr valign=top bgcolor="#eeeeff">
    206  *     <td><code>#</code>
    207  *     <td>Number
    208  *     <td>Yes
    209  *     <td>Digit, zero shows as absent
    210  *   <tr valign=top>
    211  *     <td><code>.</code>
    212  *     <td>Number
    213  *     <td>Yes
    214  *     <td>Decimal separator or monetary decimal separator
    215  *   <tr valign=top bgcolor="#eeeeff">
    216  *     <td><code>-</code>
    217  *     <td>Number
    218  *     <td>Yes
    219  *     <td>Minus sign
    220  *   <tr valign=top>
    221  *     <td><code>,</code>
    222  *     <td>Number
    223  *     <td>Yes
    224  *     <td>Grouping separator
    225  *   <tr valign=top bgcolor="#eeeeff">
    226  *     <td><code>E</code>
    227  *     <td>Number
    228  *     <td>Yes
    229  *     <td>Separates mantissa and exponent in scientific notation.
    230  *         <em>Need not be quoted in prefix or suffix.</em>
    231  *   <tr valign=top>
    232  *     <td><code>+</code>
    233  *     <td>Exponent
    234  *     <td>Yes
    235  *     <td>Prefix positive exponents with localized plus sign.
    236  *         <em>Need not be quoted in prefix or suffix.</em>
    237  *   <tr valign=top bgcolor="#eeeeff">
    238  *     <td><code>;</code>
    239  *     <td>Subpattern boundary
    240  *     <td>Yes
    241  *     <td>Separates positive and negative subpatterns
    242  *   <tr valign=top>
    243  *     <td><code>\%</code>
    244  *     <td>Prefix or suffix
    245  *     <td>Yes
    246  *     <td>Multiply by 100 and show as percentage
    247  *   <tr valign=top bgcolor="#eeeeff">
    248  *     <td><code>\\u2030</code>
    249  *     <td>Prefix or suffix
    250  *     <td>Yes
    251  *     <td>Multiply by 1000 and show as per mille
    252  *   <tr valign=top>
    253  *     <td><code>\htmlonly&curren;\endhtmlonly</code> (<code>\\u00A4</code>)
    254  *     <td>Prefix or suffix
    255  *     <td>No
    256  *     <td>Currency sign, replaced by currency symbol.  If
    257  *         doubled, replaced by international currency symbol.
    258  *         If tripled, replaced by currency plural names, for example,
    259  *         "US dollar" or "US dollars" for America.
    260  *         If present in a pattern, the monetary decimal separator
    261  *         is used instead of the decimal separator.
    262  *   <tr valign=top bgcolor="#eeeeff">
    263  *     <td><code>'</code>
    264  *     <td>Prefix or suffix
    265  *     <td>No
    266  *     <td>Used to quote special characters in a prefix or suffix,
    267  *         for example, <code>"'#'#"</code> formats 123 to
    268  *         <code>"#123"</code>.  To create a single quote
    269  *         itself, use two in a row: <code>"# o''clock"</code>.
    270  *   <tr valign=top>
    271  *     <td><code>*</code>
    272  *     <td>Prefix or suffix boundary
    273  *     <td>Yes
    274  *     <td>Pad escape, precedes pad character
    275  * </table>
    276  *
    277  * <p>A DecimalFormat pattern contains a postive and negative
    278  * subpattern, for example, "#,##0.00;(#,##0.00)".  Each subpattern has a
    279  * prefix, a numeric part, and a suffix.  If there is no explicit negative
    280  * subpattern, the negative subpattern is the localized minus sign prefixed to the
    281  * positive subpattern. That is, "0.00" alone is equivalent to "0.00;-0.00".  If there
    282  * is an explicit negative subpattern, it serves only to specify the negative
    283  * prefix and suffix; the number of digits, minimal digits, and other
    284  * characteristics are ignored in the negative subpattern. That means that
    285  * "#,##0.0#;(#)" has precisely the same result as "#,##0.0#;(#,##0.0#)".
    286  *
    287  * <p>The prefixes, suffixes, and various symbols used for infinity, digits,
    288  * thousands separators, decimal separators, etc. may be set to arbitrary
    289  * values, and they will appear properly during formatting.  However, care must
    290  * be taken that the symbols and strings do not conflict, or parsing will be
    291  * unreliable.  For example, either the positive and negative prefixes or the
    292  * suffixes must be distinct for parse() to be able
    293  * to distinguish positive from negative values.  Another example is that the
    294  * decimal separator and thousands separator should be distinct characters, or
    295  * parsing will be impossible.
    296  *
    297  * <p>The <em>grouping separator</em> is a character that separates clusters of
    298  * integer digits to make large numbers more legible.  It commonly used for
    299  * thousands, but in some locales it separates ten-thousands.  The <em>grouping
    300  * size</em> is the number of digits between the grouping separators, such as 3
    301  * for "100,000,000" or 4 for "1 0000 0000". There are actually two different
    302  * grouping sizes: One used for the least significant integer digits, the
    303  * <em>primary grouping size</em>, and one used for all others, the
    304  * <em>secondary grouping size</em>.  In most locales these are the same, but
    305  * sometimes they are different. For example, if the primary grouping interval
    306  * is 3, and the secondary is 2, then this corresponds to the pattern
    307  * "#,##,##0", and the number 123456789 is formatted as "12,34,56,789".  If a
    308  * pattern contains multiple grouping separators, the interval between the last
    309  * one and the end of the integer defines the primary grouping size, and the
    310  * interval between the last two defines the secondary grouping size. All others
    311  * are ignored, so "#,##,###,####" == "###,###,####" == "##,#,###,####".
    312  *
    313  * <p>Illegal patterns, such as "#.#.#" or "#.###,###", will cause
    314  * DecimalFormat to set a failing UErrorCode.
    315  *
    316  * <p><strong>Pattern BNF</strong>
    317  *
    318  * <pre>
    319  * pattern    := subpattern (';' subpattern)?
    320  * subpattern := prefix? number exponent? suffix?
    321  * number     := (integer ('.' fraction)?) | sigDigits
    322  * prefix     := '\\u0000'..'\\uFFFD' - specialCharacters
    323  * suffix     := '\\u0000'..'\\uFFFD' - specialCharacters
    324  * integer    := '#'* '0'* '0'
    325  * fraction   := '0'* '#'*
    326  * sigDigits  := '#'* '@' '@'* '#'*
    327  * exponent   := 'E' '+'? '0'* '0'
    328  * padSpec    := '*' padChar
    329  * padChar    := '\\u0000'..'\\uFFFD' - quote
    330  * &nbsp;
    331  * Notation:
    332  *   X*       0 or more instances of X
    333  *   X?       0 or 1 instances of X
    334  *   X|Y      either X or Y
    335  *   C..D     any character from C up to D, inclusive
    336  *   S-T      characters in S, except those in T
    337  * </pre>
    338  * The first subpattern is for positive numbers. The second (optional)
    339  * subpattern is for negative numbers.
    340  *
    341  * <p>Not indicated in the BNF syntax above:
    342  *
    343  * <ul><li>The grouping separator ',' can occur inside the integer and
    344  * sigDigits elements, between any two pattern characters of that
    345  * element, as long as the integer or sigDigits element is not
    346  * followed by the exponent element.
    347  *
    348  * <li>Two grouping intervals are recognized: That between the
    349  *     decimal point and the first grouping symbol, and that
    350  *     between the first and second grouping symbols. These
    351  *     intervals are identical in most locales, but in some
    352  *     locales they differ. For example, the pattern
    353  *     &quot;#,##,###&quot; formats the number 123456789 as
    354  *     &quot;12,34,56,789&quot;.</li>
    355  *
    356  * <li>The pad specifier <code>padSpec</code> may appear before the prefix,
    357  * after the prefix, before the suffix, after the suffix, or not at all.
    358  *
    359  * <li>In place of '0', the digits '1' through '9' may be used to
    360  * indicate a rounding increment.
    361  * </ul>
    362  *
    363  * <p><strong>Parsing</strong>
    364  *
    365  * <p>DecimalFormat parses all Unicode characters that represent
    366  * decimal digits, as defined by u_charDigitValue().  In addition,
    367  * DecimalFormat also recognizes as digits the ten consecutive
    368  * characters starting with the localized zero digit defined in the
    369  * DecimalFormatSymbols object.  During formatting, the
    370  * DecimalFormatSymbols-based digits are output.
    371  *
    372  * <p>During parsing, grouping separators are ignored if in lenient mode;
    373  * otherwise, if present, they must be in appropriate positions.
    374  *
    375  * <p>For currency parsing, the formatter is able to parse every currency
    376  * style formats no matter which style the formatter is constructed with.
    377  * For example, a formatter instance gotten from
    378  * NumberFormat.getInstance(ULocale, NumberFormat.CURRENCYSTYLE) can parse
    379  * formats such as "USD1.00" and "3.00 US dollars".
    380  *
    381  * <p>If parse(UnicodeString&,Formattable&,ParsePosition&)
    382  * fails to parse a string, it leaves the parse position unchanged.
    383  * The convenience method parse(UnicodeString&,Formattable&,UErrorCode&)
    384  * indicates parse failure by setting a failing
    385  * UErrorCode.
    386  *
    387  * <p><strong>Formatting</strong>
    388  *
    389  * <p>Formatting is guided by several parameters, all of which can be
    390  * specified either using a pattern or using the API.  The following
    391  * description applies to formats that do not use <a href="#sci">scientific
    392  * notation</a> or <a href="#sigdig">significant digits</a>.
    393  *
    394  * <ul><li>If the number of actual integer digits exceeds the
    395  * <em>maximum integer digits</em>, then only the least significant
    396  * digits are shown.  For example, 1997 is formatted as "97" if the
    397  * maximum integer digits is set to 2.
    398  *
    399  * <li>If the number of actual integer digits is less than the
    400  * <em>minimum integer digits</em>, then leading zeros are added.  For
    401  * example, 1997 is formatted as "01997" if the minimum integer digits
    402  * is set to 5.
    403  *
    404  * <li>If the number of actual fraction digits exceeds the <em>maximum
    405  * fraction digits</em>, then rounding is performed to the
    406  * maximum fraction digits.  For example, 0.125 is formatted as "0.12"
    407  * if the maximum fraction digits is 2.  This behavior can be changed
    408  * by specifying a rounding increment and/or a rounding mode.
    409  *
    410  * <li>If the number of actual fraction digits is less than the
    411  * <em>minimum fraction digits</em>, then trailing zeros are added.
    412  * For example, 0.125 is formatted as "0.1250" if the mimimum fraction
    413  * digits is set to 4.
    414  *
    415  * <li>Trailing fractional zeros are not displayed if they occur
    416  * <em>j</em> positions after the decimal, where <em>j</em> is less
    417  * than the maximum fraction digits. For example, 0.10004 is
    418  * formatted as "0.1" if the maximum fraction digits is four or less.
    419  * </ul>
    420  *
    421  * <p><strong>Special Values</strong>
    422  *
    423  * <p><code>NaN</code> is represented as a single character, typically
    424  * <code>\\uFFFD</code>.  This character is determined by the
    425  * DecimalFormatSymbols object.  This is the only value for which
    426  * the prefixes and suffixes are not used.
    427  *
    428  * <p>Infinity is represented as a single character, typically
    429  * <code>\\u221E</code>, with the positive or negative prefixes and suffixes
    430  * applied.  The infinity character is determined by the
    431  * DecimalFormatSymbols object.
    432  *
    433  * <a name="sci"><strong>Scientific Notation</strong></a>
    434  *
    435  * <p>Numbers in scientific notation are expressed as the product of a mantissa
    436  * and a power of ten, for example, 1234 can be expressed as 1.234 x 10<sup>3</sup>. The
    437  * mantissa is typically in the half-open interval [1.0, 10.0) or sometimes [0.0, 1.0),
    438  * but it need not be.  DecimalFormat supports arbitrary mantissas.
    439  * DecimalFormat can be instructed to use scientific
    440  * notation through the API or through the pattern.  In a pattern, the exponent
    441  * character immediately followed by one or more digit characters indicates
    442  * scientific notation.  Example: "0.###E0" formats the number 1234 as
    443  * "1.234E3".
    444  *
    445  * <ul>
    446  * <li>The number of digit characters after the exponent character gives the
    447  * minimum exponent digit count.  There is no maximum.  Negative exponents are
    448  * formatted using the localized minus sign, <em>not</em> the prefix and suffix
    449  * from the pattern.  This allows patterns such as "0.###E0 m/s".  To prefix
    450  * positive exponents with a localized plus sign, specify '+' between the
    451  * exponent and the digits: "0.###E+0" will produce formats "1E+1", "1E+0",
    452  * "1E-1", etc.  (In localized patterns, use the localized plus sign rather than
    453  * '+'.)
    454  *
    455  * <li>The minimum number of integer digits is achieved by adjusting the
    456  * exponent.  Example: 0.00123 formatted with "00.###E0" yields "12.3E-4".  This
    457  * only happens if there is no maximum number of integer digits.  If there is a
    458  * maximum, then the minimum number of integer digits is fixed at one.
    459  *
    460  * <li>The maximum number of integer digits, if present, specifies the exponent
    461  * grouping.  The most common use of this is to generate <em>engineering
    462  * notation</em>, in which the exponent is a multiple of three, e.g.,
    463  * "##0.###E0".  The number 12345 is formatted using "##0.####E0" as "12.345E3".
    464  *
    465  * <li>When using scientific notation, the formatter controls the
    466  * digit counts using significant digits logic.  The maximum number of
    467  * significant digits limits the total number of integer and fraction
    468  * digits that will be shown in the mantissa; it does not affect
    469  * parsing.  For example, 12345 formatted with "##0.##E0" is "12.3E3".
    470  * See the section on significant digits for more details.
    471  *
    472  * <li>The number of significant digits shown is determined as
    473  * follows: If areSignificantDigitsUsed() returns false, then the
    474  * minimum number of significant digits shown is one, and the maximum
    475  * number of significant digits shown is the sum of the <em>minimum
    476  * integer</em> and <em>maximum fraction</em> digits, and is
    477  * unaffected by the maximum integer digits.  If this sum is zero,
    478  * then all significant digits are shown.  If
    479  * areSignificantDigitsUsed() returns true, then the significant digit
    480  * counts are specified by getMinimumSignificantDigits() and
    481  * getMaximumSignificantDigits().  In this case, the number of
    482  * integer digits is fixed at one, and there is no exponent grouping.
    483  *
    484  * <li>Exponential patterns may not contain grouping separators.
    485  * </ul>
    486  *
    487  * <a name="sigdig"><strong>Significant Digits</strong></a>
    488  *
    489  * <code>DecimalFormat</code> has two ways of controlling how many
    490  * digits are shows: (a) significant digits counts, or (b) integer and
    491  * fraction digit counts.  Integer and fraction digit counts are
    492  * described above.  When a formatter is using significant digits
    493  * counts, the number of integer and fraction digits is not specified
    494  * directly, and the formatter settings for these counts are ignored.
    495  * Instead, the formatter uses however many integer and fraction
    496  * digits are required to display the specified number of significant
    497  * digits.  Examples:
    498  *
    499  * <table border=0 cellspacing=3 cellpadding=0>
    500  *   <tr bgcolor="#ccccff">
    501  *     <td align=left>Pattern
    502  *     <td align=left>Minimum significant digits
    503  *     <td align=left>Maximum significant digits
    504  *     <td align=left>Number
    505  *     <td align=left>Output of format()
    506  *   <tr valign=top>
    507  *     <td><code>\@\@\@</code>
    508  *     <td>3
    509  *     <td>3
    510  *     <td>12345
    511  *     <td><code>12300</code>
    512  *   <tr valign=top bgcolor="#eeeeff">
    513  *     <td><code>\@\@\@</code>
    514  *     <td>3
    515  *     <td>3
    516  *     <td>0.12345
    517  *     <td><code>0.123</code>
    518  *   <tr valign=top>
    519  *     <td><code>\@\@##</code>
    520  *     <td>2
    521  *     <td>4
    522  *     <td>3.14159
    523  *     <td><code>3.142</code>
    524  *   <tr valign=top bgcolor="#eeeeff">
    525  *     <td><code>\@\@##</code>
    526  *     <td>2
    527  *     <td>4
    528  *     <td>1.23004
    529  *     <td><code>1.23</code>
    530  * </table>
    531  *
    532  * <ul>
    533  * <li>Significant digit counts may be expressed using patterns that
    534  * specify a minimum and maximum number of significant digits.  These
    535  * are indicated by the <code>'@'</code> and <code>'#'</code>
    536  * characters.  The minimum number of significant digits is the number
    537  * of <code>'@'</code> characters.  The maximum number of significant
    538  * digits is the number of <code>'@'</code> characters plus the number
    539  * of <code>'#'</code> characters following on the right.  For
    540  * example, the pattern <code>"@@@"</code> indicates exactly 3
    541  * significant digits.  The pattern <code>"@##"</code> indicates from
    542  * 1 to 3 significant digits.  Trailing zero digits to the right of
    543  * the decimal separator are suppressed after the minimum number of
    544  * significant digits have been shown.  For example, the pattern
    545  * <code>"@##"</code> formats the number 0.1203 as
    546  * <code>"0.12"</code>.
    547  *
    548  * <li>If a pattern uses significant digits, it may not contain a
    549  * decimal separator, nor the <code>'0'</code> pattern character.
    550  * Patterns such as <code>"@00"</code> or <code>"@.###"</code> are
    551  * disallowed.
    552  *
    553  * <li>Any number of <code>'#'</code> characters may be prepended to
    554  * the left of the leftmost <code>'@'</code> character.  These have no
    555  * effect on the minimum and maximum significant digits counts, but
    556  * may be used to position grouping separators.  For example,
    557  * <code>"#,#@#"</code> indicates a minimum of one significant digits,
    558  * a maximum of two significant digits, and a grouping size of three.
    559  *
    560  * <li>In order to enable significant digits formatting, use a pattern
    561  * containing the <code>'@'</code> pattern character.  Alternatively,
    562  * call setSignificantDigitsUsed(TRUE).
    563  *
    564  * <li>In order to disable significant digits formatting, use a
    565  * pattern that does not contain the <code>'@'</code> pattern
    566  * character. Alternatively, call setSignificantDigitsUsed(FALSE).
    567  *
    568  * <li>The number of significant digits has no effect on parsing.
    569  *
    570  * <li>Significant digits may be used together with exponential notation. Such
    571  * patterns are equivalent to a normal exponential pattern with a minimum and
    572  * maximum integer digit count of one, a minimum fraction digit count of
    573  * <code>getMinimumSignificantDigits() - 1</code>, and a maximum fraction digit
    574  * count of <code>getMaximumSignificantDigits() - 1</code>. For example, the
    575  * pattern <code>"@@###E0"</code> is equivalent to <code>"0.0###E0"</code>.
    576  *
    577  * <li>If signficant digits are in use, then the integer and fraction
    578  * digit counts, as set via the API, are ignored.  If significant
    579  * digits are not in use, then the signficant digit counts, as set via
    580  * the API, are ignored.
    581  *
    582  * </ul>
    583  *
    584  * <p><strong>Padding</strong>
    585  *
    586  * <p>DecimalFormat supports padding the result of
    587  * format() to a specific width.  Padding may be specified either
    588  * through the API or through the pattern syntax.  In a pattern the pad escape
    589  * character, followed by a single pad character, causes padding to be parsed
    590  * and formatted.  The pad escape character is '*' in unlocalized patterns, and
    591  * can be localized using DecimalFormatSymbols::setSymbol() with a
    592  * DecimalFormatSymbols::kPadEscapeSymbol
    593  * selector.  For example, <code>"$*x#,##0.00"</code> formats 123 to
    594  * <code>"$xx123.00"</code>, and 1234 to <code>"$1,234.00"</code>.
    595  *
    596  * <ul>
    597  * <li>When padding is in effect, the width of the positive subpattern,
    598  * including prefix and suffix, determines the format width.  For example, in
    599  * the pattern <code>"* #0 o''clock"</code>, the format width is 10.
    600  *
    601  * <li>The width is counted in 16-bit code units (UChars).
    602  *
    603  * <li>Some parameters which usually do not matter have meaning when padding is
    604  * used, because the pattern width is significant with padding.  In the pattern
    605  * "* ##,##,#,##0.##", the format width is 14.  The initial characters "##,##,"
    606  * do not affect the grouping size or maximum integer digits, but they do affect
    607  * the format width.
    608  *
    609  * <li>Padding may be inserted at one of four locations: before the prefix,
    610  * after the prefix, before the suffix, or after the suffix.  If padding is
    611  * specified in any other location, applyPattern()
    612  * sets a failing UErrorCode.  If there is no prefix,
    613  * before the prefix and after the prefix are equivalent, likewise for the
    614  * suffix.
    615  *
    616  * <li>When specified in a pattern, the 32-bit code point immediately
    617  * following the pad escape is the pad character. This may be any character,
    618  * including a special pattern character. That is, the pad escape
    619  * <em>escapes</em> the following character. If there is no character after
    620  * the pad escape, then the pattern is illegal.
    621  *
    622  * </ul>
    623  *
    624  * <p><strong>Rounding</strong>
    625  *
    626  * <p>DecimalFormat supports rounding to a specific increment.  For
    627  * example, 1230 rounded to the nearest 50 is 1250.  1.234 rounded to the
    628  * nearest 0.65 is 1.3.  The rounding increment may be specified through the API
    629  * or in a pattern.  To specify a rounding increment in a pattern, include the
    630  * increment in the pattern itself.  "#,#50" specifies a rounding increment of
    631  * 50.  "#,##0.05" specifies a rounding increment of 0.05.
    632  *
    633  * <p>In the absense of an explicit rounding increment numbers are
    634  * rounded to their formatted width.
    635  *
    636  * <ul>
    637  * <li>Rounding only affects the string produced by formatting.  It does
    638  * not affect parsing or change any numerical values.
    639  *
    640  * <li>A <em>rounding mode</em> determines how values are rounded; see
    641  * DecimalFormat::ERoundingMode.  The default rounding mode is
    642  * DecimalFormat::kRoundHalfEven.  The rounding mode can only be set
    643  * through the API; it can not be set with a pattern.
    644  *
    645  * <li>Some locales use rounding in their currency formats to reflect the
    646  * smallest currency denomination.
    647  *
    648  * <li>In a pattern, digits '1' through '9' specify rounding, but otherwise
    649  * behave identically to digit '0'.
    650  * </ul>
    651  *
    652  * <p><strong>Synchronization</strong>
    653  *
    654  * <p>DecimalFormat objects are not synchronized.  Multiple
    655  * threads should not access one formatter concurrently.
    656  *
    657  * <p><strong>Subclassing</strong>
    658  *
    659  * <p><em>User subclasses are not supported.</em> While clients may write
    660  * subclasses, such code will not necessarily work and will not be
    661  * guaranteed to work stably from release to release.
    662  */
    663 class U_I18N_API DecimalFormat: public NumberFormat {
    664 public:
    665     /**
    666      * Rounding mode.
    667      * @stable ICU 2.4
    668      */
    669     enum ERoundingMode {
    670         kRoundCeiling,  /**< Round towards positive infinity */
    671         kRoundFloor,    /**< Round towards negative infinity */
    672         kRoundDown,     /**< Round towards zero */
    673         kRoundUp,       /**< Round away from zero */
    674         kRoundHalfEven, /**< Round towards the nearest integer, or
    675                              towards the nearest even integer if equidistant */
    676         kRoundHalfDown, /**< Round towards the nearest integer, or
    677                              towards zero if equidistant */
    678         kRoundHalfUp,   /**< Round towards the nearest integer, or
    679                              away from zero if equidistant */
    680         /**
    681           *  Return U_FORMAT_INEXACT_ERROR if number does not format exactly.
    682           *  @stable ICU 4.8
    683           */
    684         kRoundUnnecessary
    685     };
    686 
    687     /**
    688      * Pad position.
    689      * @stable ICU 2.4
    690      */
    691     enum EPadPosition {
    692         kPadBeforePrefix,
    693         kPadAfterPrefix,
    694         kPadBeforeSuffix,
    695         kPadAfterSuffix
    696     };
    697 
    698     /**
    699      * Create a DecimalFormat using the default pattern and symbols
    700      * for the default locale. This is a convenient way to obtain a
    701      * DecimalFormat when internationalization is not the main concern.
    702      * <P>
    703      * To obtain standard formats for a given locale, use the factory methods
    704      * on NumberFormat such as createInstance. These factories will
    705      * return the most appropriate sub-class of NumberFormat for a given
    706      * locale.
    707      * @param status    Output param set to success/failure code. If the
    708      *                  pattern is invalid this will be set to a failure code.
    709      * @stable ICU 2.0
    710      */
    711     DecimalFormat(UErrorCode& status);
    712 
    713     /**
    714      * Create a DecimalFormat from the given pattern and the symbols
    715      * for the default locale. This is a convenient way to obtain a
    716      * DecimalFormat when internationalization is not the main concern.
    717      * <P>
    718      * To obtain standard formats for a given locale, use the factory methods
    719      * on NumberFormat such as createInstance. These factories will
    720      * return the most appropriate sub-class of NumberFormat for a given
    721      * locale.
    722      * @param pattern   A non-localized pattern string.
    723      * @param status    Output param set to success/failure code. If the
    724      *                  pattern is invalid this will be set to a failure code.
    725      * @stable ICU 2.0
    726      */
    727     DecimalFormat(const UnicodeString& pattern,
    728                   UErrorCode& status);
    729 
    730     /**
    731      * Create a DecimalFormat from the given pattern and symbols.
    732      * Use this constructor when you need to completely customize the
    733      * behavior of the format.
    734      * <P>
    735      * To obtain standard formats for a given
    736      * locale, use the factory methods on NumberFormat such as
    737      * createInstance or createCurrencyInstance. If you need only minor adjustments
    738      * to a standard format, you can modify the format returned by
    739      * a NumberFormat factory method.
    740      *
    741      * @param pattern           a non-localized pattern string
    742      * @param symbolsToAdopt    the set of symbols to be used.  The caller should not
    743      *                          delete this object after making this call.
    744      * @param status            Output param set to success/failure code. If the
    745      *                          pattern is invalid this will be set to a failure code.
    746      * @stable ICU 2.0
    747      */
    748     DecimalFormat(  const UnicodeString& pattern,
    749                     DecimalFormatSymbols* symbolsToAdopt,
    750                     UErrorCode& status);
    751 
    752 #ifndef U_HIDE_INTERNAL_API
    753     /**
    754      * This API is for ICU use only.
    755      * Create a DecimalFormat from the given pattern, symbols, and style.
    756      *
    757      * @param pattern           a non-localized pattern string
    758      * @param symbolsToAdopt    the set of symbols to be used.  The caller should not
    759      *                          delete this object after making this call.
    760      * @param style             style of decimal format
    761      * @param status            Output param set to success/failure code. If the
    762      *                          pattern is invalid this will be set to a failure code.
    763      * @internal
    764      */
    765     DecimalFormat(  const UnicodeString& pattern,
    766                     DecimalFormatSymbols* symbolsToAdopt,
    767                     UNumberFormatStyle style,
    768                     UErrorCode& status);
    769 
    770 #if UCONFIG_HAVE_PARSEALLINPUT
    771     /**
    772      * @internal
    773      */
    774     void setParseAllInput(UNumberFormatAttributeValue value);
    775 #endif
    776 
    777 #endif  /* U_HIDE_INTERNAL_API */
    778 
    779 
    780     /**
    781      * Set an integer attribute on this DecimalFormat.
    782      * May return U_UNSUPPORTED_ERROR if this instance does not support
    783      * the specified attribute.
    784      * @param attr the attribute to set
    785      * @param newvalue new value
    786      * @param status the error type
    787      * @return *this - for chaining (example: format.setAttribute(...).setAttribute(...) )
    788      * @stable ICU 51
    789      */
    790     virtual DecimalFormat& setAttribute( UNumberFormatAttribute attr,
    791                                        int32_t newvalue,
    792                                        UErrorCode &status);
    793 
    794     /**
    795      * Get an integer
    796      * May return U_UNSUPPORTED_ERROR if this instance does not support
    797      * the specified attribute.
    798      * @param attr the attribute to set
    799      * @param status the error type
    800      * @return the attribute value. Undefined if there is an error.
    801      * @stable ICU 51
    802      */
    803     virtual int32_t getAttribute( UNumberFormatAttribute attr,
    804                                   UErrorCode &status) const;
    805 
    806 
    807     /**
    808      * Set whether or not grouping will be used in this format.
    809      * @param newValue    True, grouping will be used in this format.
    810      * @see getGroupingUsed
    811      * @stable ICU 53
    812      */
    813     virtual void setGroupingUsed(UBool newValue);
    814 
    815     /**
    816      * Sets whether or not numbers should be parsed as integers only.
    817      * @param value    set True, this format will parse numbers as integers
    818      *                 only.
    819      * @see isParseIntegerOnly
    820      * @stable ICU 53
    821      */
    822     virtual void setParseIntegerOnly(UBool value);
    823 
    824     /**
    825      * Set a particular UDisplayContext value in the formatter, such as
    826      * UDISPCTX_CAPITALIZATION_FOR_STANDALONE.
    827      * @param value The UDisplayContext value to set.
    828      * @param status Input/output status. If at entry this indicates a failure
    829      *               status, the function will do nothing; otherwise this will be
    830      *               updated with any new status from the function.
    831      * @stable ICU 53
    832      */
    833     virtual void setContext(UDisplayContext value, UErrorCode& status);
    834 
    835     /**
    836      * Create a DecimalFormat from the given pattern and symbols.
    837      * Use this constructor when you need to completely customize the
    838      * behavior of the format.
    839      * <P>
    840      * To obtain standard formats for a given
    841      * locale, use the factory methods on NumberFormat such as
    842      * createInstance or createCurrencyInstance. If you need only minor adjustments
    843      * to a standard format, you can modify the format returned by
    844      * a NumberFormat factory method.
    845      *
    846      * @param pattern           a non-localized pattern string
    847      * @param symbolsToAdopt    the set of symbols to be used.  The caller should not
    848      *                          delete this object after making this call.
    849      * @param parseError        Output param to receive errors occured during parsing
    850      * @param status            Output param set to success/failure code. If the
    851      *                          pattern is invalid this will be set to a failure code.
    852      * @stable ICU 2.0
    853      */
    854     DecimalFormat(  const UnicodeString& pattern,
    855                     DecimalFormatSymbols* symbolsToAdopt,
    856                     UParseError& parseError,
    857                     UErrorCode& status);
    858     /**
    859      * Create a DecimalFormat from the given pattern and symbols.
    860      * Use this constructor when you need to completely customize the
    861      * behavior of the format.
    862      * <P>
    863      * To obtain standard formats for a given
    864      * locale, use the factory methods on NumberFormat such as
    865      * createInstance or createCurrencyInstance. If you need only minor adjustments
    866      * to a standard format, you can modify the format returned by
    867      * a NumberFormat factory method.
    868      *
    869      * @param pattern           a non-localized pattern string
    870      * @param symbols   the set of symbols to be used
    871      * @param status            Output param set to success/failure code. If the
    872      *                          pattern is invalid this will be set to a failure code.
    873      * @stable ICU 2.0
    874      */
    875     DecimalFormat(  const UnicodeString& pattern,
    876                     const DecimalFormatSymbols& symbols,
    877                     UErrorCode& status);
    878 
    879     /**
    880      * Copy constructor.
    881      *
    882      * @param source    the DecimalFormat object to be copied from.
    883      * @stable ICU 2.0
    884      */
    885     DecimalFormat(const DecimalFormat& source);
    886 
    887     /**
    888      * Assignment operator.
    889      *
    890      * @param rhs    the DecimalFormat object to be copied.
    891      * @stable ICU 2.0
    892      */
    893     DecimalFormat& operator=(const DecimalFormat& rhs);
    894 
    895     /**
    896      * Destructor.
    897      * @stable ICU 2.0
    898      */
    899     virtual ~DecimalFormat();
    900 
    901     /**
    902      * Clone this Format object polymorphically. The caller owns the
    903      * result and should delete it when done.
    904      *
    905      * @return    a polymorphic copy of this DecimalFormat.
    906      * @stable ICU 2.0
    907      */
    908     virtual Format* clone(void) const;
    909 
    910     /**
    911      * Return true if the given Format objects are semantically equal.
    912      * Objects of different subclasses are considered unequal.
    913      *
    914      * @param other    the object to be compared with.
    915      * @return         true if the given Format objects are semantically equal.
    916      * @stable ICU 2.0
    917      */
    918     virtual UBool operator==(const Format& other) const;
    919 
    920 
    921     using NumberFormat::format;
    922 
    923     /**
    924      * Format a double or long number using base-10 representation.
    925      *
    926      * @param number    The value to be formatted.
    927      * @param appendTo  Output parameter to receive result.
    928      *                  Result is appended to existing contents.
    929      * @param pos       On input: an alignment field, if desired.
    930      *                  On output: the offsets of the alignment field.
    931      * @return          Reference to 'appendTo' parameter.
    932      * @stable ICU 2.0
    933      */
    934     virtual UnicodeString& format(double number,
    935                                   UnicodeString& appendTo,
    936                                   FieldPosition& pos) const;
    937 
    938 
    939     /**
    940      * Format a double or long number using base-10 representation.
    941      *
    942      * @param number    The value to be formatted.
    943      * @param appendTo  Output parameter to receive result.
    944      *                  Result is appended to existing contents.
    945      * @param pos       On input: an alignment field, if desired.
    946      *                  On output: the offsets of the alignment field.
    947      * @param status
    948      * @return          Reference to 'appendTo' parameter.
    949      * @internal
    950      */
    951     virtual UnicodeString& format(double number,
    952                                   UnicodeString& appendTo,
    953                                   FieldPosition& pos,
    954                                   UErrorCode &status) const;
    955 
    956     /**
    957      * Format a double or long number using base-10 representation.
    958      *
    959      * @param number    The value to be formatted.
    960      * @param appendTo  Output parameter to receive result.
    961      *                  Result is appended to existing contents.
    962      * @param posIter   On return, can be used to iterate over positions
    963      *                  of fields generated by this format call.
    964      *                  Can be NULL.
    965      * @param status    Output param filled with success/failure status.
    966      * @return          Reference to 'appendTo' parameter.
    967      * @stable 4.4
    968      */
    969     virtual UnicodeString& format(double number,
    970                                   UnicodeString& appendTo,
    971                                   FieldPositionIterator* posIter,
    972                                   UErrorCode& status) const;
    973 
    974     /**
    975      * Format a long number using base-10 representation.
    976      *
    977      * @param number    The value to be formatted.
    978      * @param appendTo  Output parameter to receive result.
    979      *                  Result is appended to existing contents.
    980      * @param pos       On input: an alignment field, if desired.
    981      *                  On output: the offsets of the alignment field.
    982      * @return          Reference to 'appendTo' parameter.
    983      * @stable ICU 2.0
    984      */
    985     virtual UnicodeString& format(int32_t number,
    986                                   UnicodeString& appendTo,
    987                                   FieldPosition& pos) const;
    988 
    989     /**
    990      * Format a long number using base-10 representation.
    991      *
    992      * @param number    The value to be formatted.
    993      * @param appendTo  Output parameter to receive result.
    994      *                  Result is appended to existing contents.
    995      * @param pos       On input: an alignment field, if desired.
    996      *                  On output: the offsets of the alignment field.
    997      * @return          Reference to 'appendTo' parameter.
    998      * @internal
    999      */
   1000     virtual UnicodeString& format(int32_t number,
   1001                                   UnicodeString& appendTo,
   1002                                   FieldPosition& pos,
   1003                                   UErrorCode &status) const;
   1004 
   1005     /**
   1006      * Format a long number using base-10 representation.
   1007      *
   1008      * @param number    The value to be formatted.
   1009      * @param appendTo  Output parameter to receive result.
   1010      *                  Result is appended to existing contents.
   1011      * @param posIter   On return, can be used to iterate over positions
   1012      *                  of fields generated by this format call.
   1013      *                  Can be NULL.
   1014      * @param status    Output param filled with success/failure status.
   1015      * @return          Reference to 'appendTo' parameter.
   1016      * @stable 4.4
   1017      */
   1018     virtual UnicodeString& format(int32_t number,
   1019                                   UnicodeString& appendTo,
   1020                                   FieldPositionIterator* posIter,
   1021                                   UErrorCode& status) const;
   1022 
   1023     /**
   1024      * Format an int64 number using base-10 representation.
   1025      *
   1026      * @param number    The value to be formatted.
   1027      * @param appendTo  Output parameter to receive result.
   1028      *                  Result is appended to existing contents.
   1029      * @param pos       On input: an alignment field, if desired.
   1030      *                  On output: the offsets of the alignment field.
   1031      * @return          Reference to 'appendTo' parameter.
   1032      * @stable ICU 2.8
   1033      */
   1034     virtual UnicodeString& format(int64_t number,
   1035                                   UnicodeString& appendTo,
   1036                                   FieldPosition& pos) const;
   1037 
   1038     /**
   1039      * Format an int64 number using base-10 representation.
   1040      *
   1041      * @param number    The value to be formatted.
   1042      * @param appendTo  Output parameter to receive result.
   1043      *                  Result is appended to existing contents.
   1044      * @param pos       On input: an alignment field, if desired.
   1045      *                  On output: the offsets of the alignment field.
   1046      * @return          Reference to 'appendTo' parameter.
   1047      * @internal
   1048      */
   1049     virtual UnicodeString& format(int64_t number,
   1050                                   UnicodeString& appendTo,
   1051                                   FieldPosition& pos,
   1052                                   UErrorCode &status) const;
   1053 
   1054     /**
   1055      * Format an int64 number using base-10 representation.
   1056      *
   1057      * @param number    The value to be formatted.
   1058      * @param appendTo  Output parameter to receive result.
   1059      *                  Result is appended to existing contents.
   1060      * @param posIter   On return, can be used to iterate over positions
   1061      *                  of fields generated by this format call.
   1062      *                  Can be NULL.
   1063      * @param status    Output param filled with success/failure status.
   1064      * @return          Reference to 'appendTo' parameter.
   1065      * @stable 4.4
   1066      */
   1067     virtual UnicodeString& format(int64_t number,
   1068                                   UnicodeString& appendTo,
   1069                                   FieldPositionIterator* posIter,
   1070                                   UErrorCode& status) const;
   1071 
   1072     /**
   1073      * Format a decimal number.
   1074      * The syntax of the unformatted number is a "numeric string"
   1075      * as defined in the Decimal Arithmetic Specification, available at
   1076      * http://speleotrove.com/decimal
   1077      *
   1078      * @param number    The unformatted number, as a string.
   1079      * @param appendTo  Output parameter to receive result.
   1080      *                  Result is appended to existing contents.
   1081      * @param posIter   On return, can be used to iterate over positions
   1082      *                  of fields generated by this format call.
   1083      *                  Can be NULL.
   1084      * @param status    Output param filled with success/failure status.
   1085      * @return          Reference to 'appendTo' parameter.
   1086      * @stable 4.4
   1087      */
   1088     virtual UnicodeString& format(const StringPiece &number,
   1089                                   UnicodeString& appendTo,
   1090                                   FieldPositionIterator* posIter,
   1091                                   UErrorCode& status) const;
   1092 
   1093 
   1094     /**
   1095      * Format a decimal number.
   1096      * The number is a DigitList wrapper onto a floating point decimal number.
   1097      * The default implementation in NumberFormat converts the decimal number
   1098      * to a double and formats that.
   1099      *
   1100      * @param number    The number, a DigitList format Decimal Floating Point.
   1101      * @param appendTo  Output parameter to receive result.
   1102      *                  Result is appended to existing contents.
   1103      * @param posIter   On return, can be used to iterate over positions
   1104      *                  of fields generated by this format call.
   1105      * @param status    Output param filled with success/failure status.
   1106      * @return          Reference to 'appendTo' parameter.
   1107      * @internal
   1108      */
   1109     virtual UnicodeString& format(const DigitList &number,
   1110                                   UnicodeString& appendTo,
   1111                                   FieldPositionIterator* posIter,
   1112                                   UErrorCode& status) const;
   1113 
   1114     /**
   1115      * Format a decimal number.
   1116      * The number is a DigitList wrapper onto a floating point decimal number.
   1117      * The default implementation in NumberFormat converts the decimal number
   1118      * to a double and formats that.
   1119      *
   1120      * @param number    The number, a DigitList format Decimal Floating Point.
   1121      * @param appendTo  Output parameter to receive result.
   1122      *                  Result is appended to existing contents.
   1123      * @param pos       On input: an alignment field, if desired.
   1124      *                  On output: the offsets of the alignment field.
   1125      * @param status    Output param filled with success/failure status.
   1126      * @return          Reference to 'appendTo' parameter.
   1127      * @internal
   1128      */
   1129     virtual UnicodeString& format(const DigitList &number,
   1130                                   UnicodeString& appendTo,
   1131                                   FieldPosition& pos,
   1132                                   UErrorCode& status) const;
   1133 
   1134    using NumberFormat::parse;
   1135 
   1136    /**
   1137     * Parse the given string using this object's choices. The method
   1138     * does string comparisons to try to find an optimal match.
   1139     * If no object can be parsed, index is unchanged, and NULL is
   1140     * returned.  The result is returned as the most parsimonious
   1141     * type of Formattable that will accomodate all of the
   1142     * necessary precision.  For example, if the result is exactly 12,
   1143     * it will be returned as a long.  However, if it is 1.5, it will
   1144     * be returned as a double.
   1145     *
   1146     * @param text           The text to be parsed.
   1147     * @param result         Formattable to be set to the parse result.
   1148     *                       If parse fails, return contents are undefined.
   1149     * @param parsePosition  The position to start parsing at on input.
   1150     *                       On output, moved to after the last successfully
   1151     *                       parse character. On parse failure, does not change.
   1152     * @see Formattable
   1153     * @stable ICU 2.0
   1154     */
   1155     virtual void parse(const UnicodeString& text,
   1156                        Formattable& result,
   1157                        ParsePosition& parsePosition) const;
   1158 
   1159     /**
   1160      * Parses text from the given string as a currency amount.  Unlike
   1161      * the parse() method, this method will attempt to parse a generic
   1162      * currency name, searching for a match of this object's locale's
   1163      * currency display names, or for a 3-letter ISO currency code.
   1164      * This method will fail if this format is not a currency format,
   1165      * that is, if it does not contain the currency pattern symbol
   1166      * (U+00A4) in its prefix or suffix.
   1167      *
   1168      * @param text the string to parse
   1169      * @param pos  input-output position; on input, the position within text
   1170      *             to match; must have 0 <= pos.getIndex() < text.length();
   1171      *             on output, the position after the last matched character.
   1172      *             If the parse fails, the position in unchanged upon output.
   1173      * @return     if parse succeeds, a pointer to a newly-created CurrencyAmount
   1174      *             object (owned by the caller) containing information about
   1175      *             the parsed currency; if parse fails, this is NULL.
   1176      * @stable ICU 49
   1177      */
   1178     virtual CurrencyAmount* parseCurrency(const UnicodeString& text,
   1179                                           ParsePosition& pos) const;
   1180 
   1181     /**
   1182      * Returns the decimal format symbols, which is generally not changed
   1183      * by the programmer or user.
   1184      * @return desired DecimalFormatSymbols
   1185      * @see DecimalFormatSymbols
   1186      * @stable ICU 2.0
   1187      */
   1188     virtual const DecimalFormatSymbols* getDecimalFormatSymbols(void) const;
   1189 
   1190     /**
   1191      * Sets the decimal format symbols, which is generally not changed
   1192      * by the programmer or user.
   1193      * @param symbolsToAdopt DecimalFormatSymbols to be adopted.
   1194      * @stable ICU 2.0
   1195      */
   1196     virtual void adoptDecimalFormatSymbols(DecimalFormatSymbols* symbolsToAdopt);
   1197 
   1198     /**
   1199      * Sets the decimal format symbols, which is generally not changed
   1200      * by the programmer or user.
   1201      * @param symbols DecimalFormatSymbols.
   1202      * @stable ICU 2.0
   1203      */
   1204     virtual void setDecimalFormatSymbols(const DecimalFormatSymbols& symbols);
   1205 
   1206 
   1207     /**
   1208      * Returns the currency plural format information,
   1209      * which is generally not changed by the programmer or user.
   1210      * @return desired CurrencyPluralInfo
   1211      * @stable ICU 4.2
   1212      */
   1213     virtual const CurrencyPluralInfo* getCurrencyPluralInfo(void) const;
   1214 
   1215     /**
   1216      * Sets the currency plural format information,
   1217      * which is generally not changed by the programmer or user.
   1218      * @param toAdopt CurrencyPluralInfo to be adopted.
   1219      * @stable ICU 4.2
   1220      */
   1221     virtual void adoptCurrencyPluralInfo(CurrencyPluralInfo* toAdopt);
   1222 
   1223     /**
   1224      * Sets the currency plural format information,
   1225      * which is generally not changed by the programmer or user.
   1226      * @param info Currency Plural Info.
   1227      * @stable ICU 4.2
   1228      */
   1229     virtual void setCurrencyPluralInfo(const CurrencyPluralInfo& info);
   1230 
   1231 
   1232     /**
   1233      * Get the positive prefix.
   1234      *
   1235      * @param result    Output param which will receive the positive prefix.
   1236      * @return          A reference to 'result'.
   1237      * Examples: +123, $123, sFr123
   1238      * @stable ICU 2.0
   1239      */
   1240     UnicodeString& getPositivePrefix(UnicodeString& result) const;
   1241 
   1242     /**
   1243      * Set the positive prefix.
   1244      *
   1245      * @param newValue    the new value of the the positive prefix to be set.
   1246      * Examples: +123, $123, sFr123
   1247      * @stable ICU 2.0
   1248      */
   1249     virtual void setPositivePrefix(const UnicodeString& newValue);
   1250 
   1251     /**
   1252      * Get the negative prefix.
   1253      *
   1254      * @param result    Output param which will receive the negative prefix.
   1255      * @return          A reference to 'result'.
   1256      * Examples: -123, ($123) (with negative suffix), sFr-123
   1257      * @stable ICU 2.0
   1258      */
   1259     UnicodeString& getNegativePrefix(UnicodeString& result) const;
   1260 
   1261     /**
   1262      * Set the negative prefix.
   1263      *
   1264      * @param newValue    the new value of the the negative prefix to be set.
   1265      * Examples: -123, ($123) (with negative suffix), sFr-123
   1266      * @stable ICU 2.0
   1267      */
   1268     virtual void setNegativePrefix(const UnicodeString& newValue);
   1269 
   1270     /**
   1271      * Get the positive suffix.
   1272      *
   1273      * @param result    Output param which will receive the positive suffix.
   1274      * @return          A reference to 'result'.
   1275      * Example: 123%
   1276      * @stable ICU 2.0
   1277      */
   1278     UnicodeString& getPositiveSuffix(UnicodeString& result) const;
   1279 
   1280     /**
   1281      * Set the positive suffix.
   1282      *
   1283      * @param newValue    the new value of the positive suffix to be set.
   1284      * Example: 123%
   1285      * @stable ICU 2.0
   1286      */
   1287     virtual void setPositiveSuffix(const UnicodeString& newValue);
   1288 
   1289     /**
   1290      * Get the negative suffix.
   1291      *
   1292      * @param result    Output param which will receive the negative suffix.
   1293      * @return          A reference to 'result'.
   1294      * Examples: -123%, ($123) (with positive suffixes)
   1295      * @stable ICU 2.0
   1296      */
   1297     UnicodeString& getNegativeSuffix(UnicodeString& result) const;
   1298 
   1299     /**
   1300      * Set the negative suffix.
   1301      *
   1302      * @param newValue    the new value of the negative suffix to be set.
   1303      * Examples: 123%
   1304      * @stable ICU 2.0
   1305      */
   1306     virtual void setNegativeSuffix(const UnicodeString& newValue);
   1307 
   1308     /**
   1309      * Get the multiplier for use in percent, permill, etc.
   1310      * For a percentage, set the suffixes to have "%" and the multiplier to be 100.
   1311      * (For Arabic, use arabic percent symbol).
   1312      * For a permill, set the suffixes to have "\\u2031" and the multiplier to be 1000.
   1313      *
   1314      * @return    the multiplier for use in percent, permill, etc.
   1315      * Examples: with 100, 1.23 -> "123", and "123" -> 1.23
   1316      * @stable ICU 2.0
   1317      */
   1318     int32_t getMultiplier(void) const;
   1319 
   1320     /**
   1321      * Set the multiplier for use in percent, permill, etc.
   1322      * For a percentage, set the suffixes to have "%" and the multiplier to be 100.
   1323      * (For Arabic, use arabic percent symbol).
   1324      * For a permill, set the suffixes to have "\\u2031" and the multiplier to be 1000.
   1325      *
   1326      * @param newValue    the new value of the multiplier for use in percent, permill, etc.
   1327      * Examples: with 100, 1.23 -> "123", and "123" -> 1.23
   1328      * @stable ICU 2.0
   1329      */
   1330     virtual void setMultiplier(int32_t newValue);
   1331 
   1332     /**
   1333      * Get the rounding increment.
   1334      * @return A positive rounding increment, or 0.0 if a custom rounding
   1335      * increment is not in effect.
   1336      * @see #setRoundingIncrement
   1337      * @see #getRoundingMode
   1338      * @see #setRoundingMode
   1339      * @stable ICU 2.0
   1340      */
   1341     virtual double getRoundingIncrement(void) const;
   1342 
   1343     /**
   1344      * Set the rounding increment.  In the absence of a rounding increment,
   1345      *    numbers will be rounded to the number of digits displayed.
   1346      * @param newValue A positive rounding increment, or 0.0 to
   1347      * use the default rounding increment.
   1348      * Negative increments are equivalent to 0.0.
   1349      * @see #getRoundingIncrement
   1350      * @see #getRoundingMode
   1351      * @see #setRoundingMode
   1352      * @stable ICU 2.0
   1353      */
   1354     virtual void setRoundingIncrement(double newValue);
   1355 
   1356     /**
   1357      * Get the rounding mode.
   1358      * @return A rounding mode
   1359      * @see #setRoundingIncrement
   1360      * @see #getRoundingIncrement
   1361      * @see #setRoundingMode
   1362      * @stable ICU 2.0
   1363      */
   1364     virtual ERoundingMode getRoundingMode(void) const;
   1365 
   1366     /**
   1367      * Set the rounding mode.
   1368      * @param roundingMode A rounding mode
   1369      * @see #setRoundingIncrement
   1370      * @see #getRoundingIncrement
   1371      * @see #getRoundingMode
   1372      * @stable ICU 2.0
   1373      */
   1374     virtual void setRoundingMode(ERoundingMode roundingMode);
   1375 
   1376     /**
   1377      * Get the width to which the output of format() is padded.
   1378      * The width is counted in 16-bit code units.
   1379      * @return the format width, or zero if no padding is in effect
   1380      * @see #setFormatWidth
   1381      * @see #getPadCharacterString
   1382      * @see #setPadCharacter
   1383      * @see #getPadPosition
   1384      * @see #setPadPosition
   1385      * @stable ICU 2.0
   1386      */
   1387     virtual int32_t getFormatWidth(void) const;
   1388 
   1389     /**
   1390      * Set the width to which the output of format() is padded.
   1391      * The width is counted in 16-bit code units.
   1392      * This method also controls whether padding is enabled.
   1393      * @param width the width to which to pad the result of
   1394      * format(), or zero to disable padding.  A negative
   1395      * width is equivalent to 0.
   1396      * @see #getFormatWidth
   1397      * @see #getPadCharacterString
   1398      * @see #setPadCharacter
   1399      * @see #getPadPosition
   1400      * @see #setPadPosition
   1401      * @stable ICU 2.0
   1402      */
   1403     virtual void setFormatWidth(int32_t width);
   1404 
   1405     /**
   1406      * Get the pad character used to pad to the format width.  The
   1407      * default is ' '.
   1408      * @return a string containing the pad character. This will always
   1409      * have a length of one 32-bit code point.
   1410      * @see #setFormatWidth
   1411      * @see #getFormatWidth
   1412      * @see #setPadCharacter
   1413      * @see #getPadPosition
   1414      * @see #setPadPosition
   1415      * @stable ICU 2.0
   1416      */
   1417     virtual UnicodeString getPadCharacterString() const;
   1418 
   1419     /**
   1420      * Set the character used to pad to the format width.  If padding
   1421      * is not enabled, then this will take effect if padding is later
   1422      * enabled.
   1423      * @param padChar a string containing the pad charcter. If the string
   1424      * has length 0, then the pad characer is set to ' '.  Otherwise
   1425      * padChar.char32At(0) will be used as the pad character.
   1426      * @see #setFormatWidth
   1427      * @see #getFormatWidth
   1428      * @see #getPadCharacterString
   1429      * @see #getPadPosition
   1430      * @see #setPadPosition
   1431      * @stable ICU 2.0
   1432      */
   1433     virtual void setPadCharacter(const UnicodeString &padChar);
   1434 
   1435     /**
   1436      * Get the position at which padding will take place.  This is the location
   1437      * at which padding will be inserted if the result of format()
   1438      * is shorter than the format width.
   1439      * @return the pad position, one of kPadBeforePrefix,
   1440      * kPadAfterPrefix, kPadBeforeSuffix, or
   1441      * kPadAfterSuffix.
   1442      * @see #setFormatWidth
   1443      * @see #getFormatWidth
   1444      * @see #setPadCharacter
   1445      * @see #getPadCharacterString
   1446      * @see #setPadPosition
   1447      * @see #EPadPosition
   1448      * @stable ICU 2.0
   1449      */
   1450     virtual EPadPosition getPadPosition(void) const;
   1451 
   1452     /**
   1453      * Set the position at which padding will take place.  This is the location
   1454      * at which padding will be inserted if the result of format()
   1455      * is shorter than the format width.  This has no effect unless padding is
   1456      * enabled.
   1457      * @param padPos the pad position, one of kPadBeforePrefix,
   1458      * kPadAfterPrefix, kPadBeforeSuffix, or
   1459      * kPadAfterSuffix.
   1460      * @see #setFormatWidth
   1461      * @see #getFormatWidth
   1462      * @see #setPadCharacter
   1463      * @see #getPadCharacterString
   1464      * @see #getPadPosition
   1465      * @see #EPadPosition
   1466      * @stable ICU 2.0
   1467      */
   1468     virtual void setPadPosition(EPadPosition padPos);
   1469 
   1470     /**
   1471      * Return whether or not scientific notation is used.
   1472      * @return TRUE if this object formats and parses scientific notation
   1473      * @see #setScientificNotation
   1474      * @see #getMinimumExponentDigits
   1475      * @see #setMinimumExponentDigits
   1476      * @see #isExponentSignAlwaysShown
   1477      * @see #setExponentSignAlwaysShown
   1478      * @stable ICU 2.0
   1479      */
   1480     virtual UBool isScientificNotation(void) const;
   1481 
   1482     /**
   1483      * Set whether or not scientific notation is used. When scientific notation
   1484      * is used, the effective maximum number of integer digits is <= 8.  If the
   1485      * maximum number of integer digits is set to more than 8, the effective
   1486      * maximum will be 1.  This allows this call to generate a 'default' scientific
   1487      * number format without additional changes.
   1488      * @param useScientific TRUE if this object formats and parses scientific
   1489      * notation
   1490      * @see #isScientificNotation
   1491      * @see #getMinimumExponentDigits
   1492      * @see #setMinimumExponentDigits
   1493      * @see #isExponentSignAlwaysShown
   1494      * @see #setExponentSignAlwaysShown
   1495      * @stable ICU 2.0
   1496      */
   1497     virtual void setScientificNotation(UBool useScientific);
   1498 
   1499     /**
   1500      * Return the minimum exponent digits that will be shown.
   1501      * @return the minimum exponent digits that will be shown
   1502      * @see #setScientificNotation
   1503      * @see #isScientificNotation
   1504      * @see #setMinimumExponentDigits
   1505      * @see #isExponentSignAlwaysShown
   1506      * @see #setExponentSignAlwaysShown
   1507      * @stable ICU 2.0
   1508      */
   1509     virtual int8_t getMinimumExponentDigits(void) const;
   1510 
   1511     /**
   1512      * Set the minimum exponent digits that will be shown.  This has no
   1513      * effect unless scientific notation is in use.
   1514      * @param minExpDig a value >= 1 indicating the fewest exponent digits
   1515      * that will be shown.  Values less than 1 will be treated as 1.
   1516      * @see #setScientificNotation
   1517      * @see #isScientificNotation
   1518      * @see #getMinimumExponentDigits
   1519      * @see #isExponentSignAlwaysShown
   1520      * @see #setExponentSignAlwaysShown
   1521      * @stable ICU 2.0
   1522      */
   1523     virtual void setMinimumExponentDigits(int8_t minExpDig);
   1524 
   1525     /**
   1526      * Return whether the exponent sign is always shown.
   1527      * @return TRUE if the exponent is always prefixed with either the
   1528      * localized minus sign or the localized plus sign, false if only negative
   1529      * exponents are prefixed with the localized minus sign.
   1530      * @see #setScientificNotation
   1531      * @see #isScientificNotation
   1532      * @see #setMinimumExponentDigits
   1533      * @see #getMinimumExponentDigits
   1534      * @see #setExponentSignAlwaysShown
   1535      * @stable ICU 2.0
   1536      */
   1537     virtual UBool isExponentSignAlwaysShown(void) const;
   1538 
   1539     /**
   1540      * Set whether the exponent sign is always shown.  This has no effect
   1541      * unless scientific notation is in use.
   1542      * @param expSignAlways TRUE if the exponent is always prefixed with either
   1543      * the localized minus sign or the localized plus sign, false if only
   1544      * negative exponents are prefixed with the localized minus sign.
   1545      * @see #setScientificNotation
   1546      * @see #isScientificNotation
   1547      * @see #setMinimumExponentDigits
   1548      * @see #getMinimumExponentDigits
   1549      * @see #isExponentSignAlwaysShown
   1550      * @stable ICU 2.0
   1551      */
   1552     virtual void setExponentSignAlwaysShown(UBool expSignAlways);
   1553 
   1554     /**
   1555      * Return the grouping size. Grouping size is the number of digits between
   1556      * grouping separators in the integer portion of a number.  For example,
   1557      * in the number "123,456.78", the grouping size is 3.
   1558      *
   1559      * @return    the grouping size.
   1560      * @see setGroupingSize
   1561      * @see NumberFormat::isGroupingUsed
   1562      * @see DecimalFormatSymbols::getGroupingSeparator
   1563      * @stable ICU 2.0
   1564      */
   1565     int32_t getGroupingSize(void) const;
   1566 
   1567     /**
   1568      * Set the grouping size. Grouping size is the number of digits between
   1569      * grouping separators in the integer portion of a number.  For example,
   1570      * in the number "123,456.78", the grouping size is 3.
   1571      *
   1572      * @param newValue    the new value of the grouping size.
   1573      * @see getGroupingSize
   1574      * @see NumberFormat::setGroupingUsed
   1575      * @see DecimalFormatSymbols::setGroupingSeparator
   1576      * @stable ICU 2.0
   1577      */
   1578     virtual void setGroupingSize(int32_t newValue);
   1579 
   1580     /**
   1581      * Return the secondary grouping size. In some locales one
   1582      * grouping interval is used for the least significant integer
   1583      * digits (the primary grouping size), and another is used for all
   1584      * others (the secondary grouping size).  A formatter supporting a
   1585      * secondary grouping size will return a positive integer unequal
   1586      * to the primary grouping size returned by
   1587      * getGroupingSize().  For example, if the primary
   1588      * grouping size is 4, and the secondary grouping size is 2, then
   1589      * the number 123456789 formats as "1,23,45,6789", and the pattern
   1590      * appears as "#,##,###0".
   1591      * @return the secondary grouping size, or a value less than
   1592      * one if there is none
   1593      * @see setSecondaryGroupingSize
   1594      * @see NumberFormat::isGroupingUsed
   1595      * @see DecimalFormatSymbols::getGroupingSeparator
   1596      * @stable ICU 2.4
   1597      */
   1598     int32_t getSecondaryGroupingSize(void) const;
   1599 
   1600     /**
   1601      * Set the secondary grouping size. If set to a value less than 1,
   1602      * then secondary grouping is turned off, and the primary grouping
   1603      * size is used for all intervals, not just the least significant.
   1604      *
   1605      * @param newValue    the new value of the secondary grouping size.
   1606      * @see getSecondaryGroupingSize
   1607      * @see NumberFormat#setGroupingUsed
   1608      * @see DecimalFormatSymbols::setGroupingSeparator
   1609      * @stable ICU 2.4
   1610      */
   1611     virtual void setSecondaryGroupingSize(int32_t newValue);
   1612 
   1613     /**
   1614      * Allows you to get the behavior of the decimal separator with integers.
   1615      * (The decimal separator will always appear with decimals.)
   1616      *
   1617      * @return    TRUE if the decimal separator always appear with decimals.
   1618      * Example: Decimal ON: 12345 -> 12345.; OFF: 12345 -> 12345
   1619      * @stable ICU 2.0
   1620      */
   1621     UBool isDecimalSeparatorAlwaysShown(void) const;
   1622 
   1623     /**
   1624      * Allows you to set the behavior of the decimal separator with integers.
   1625      * (The decimal separator will always appear with decimals.)
   1626      *
   1627      * @param newValue    set TRUE if the decimal separator will always appear with decimals.
   1628      * Example: Decimal ON: 12345 -> 12345.; OFF: 12345 -> 12345
   1629      * @stable ICU 2.0
   1630      */
   1631     virtual void setDecimalSeparatorAlwaysShown(UBool newValue);
   1632 
   1633 #ifndef U_HIDE_DRAFT_API
   1634     /**
   1635      * Allows you to get the parse behavior of the pattern decimal mark.
   1636      *
   1637      * @return    TRUE if input must contain a match to decimal mark in pattern
   1638      * @draft ICU 54
   1639      */
   1640     UBool isDecimalPatternMatchRequired(void) const;
   1641 #endif  /* U_HIDE_DRAFT_API */
   1642 
   1643     /**
   1644      * Allows you to set the behavior of the pattern decimal mark.
   1645      *
   1646      * if TRUE, the input must have a decimal mark if one was specified in the pattern. When
   1647      * FALSE the decimal mark may be omitted from the input.
   1648      *
   1649      * @param newValue    set TRUE if input must contain a match to decimal mark in pattern
   1650      * @draft ICU 54
   1651      */
   1652     virtual void setDecimalPatternMatchRequired(UBool newValue);
   1653 
   1654 
   1655     /**
   1656      * Synthesizes a pattern string that represents the current state
   1657      * of this Format object.
   1658      *
   1659      * @param result    Output param which will receive the pattern.
   1660      *                  Previous contents are deleted.
   1661      * @return          A reference to 'result'.
   1662      * @see applyPattern
   1663      * @stable ICU 2.0
   1664      */
   1665     virtual UnicodeString& toPattern(UnicodeString& result) const;
   1666 
   1667     /**
   1668      * Synthesizes a localized pattern string that represents the current
   1669      * state of this Format object.
   1670      *
   1671      * @param result    Output param which will receive the localized pattern.
   1672      *                  Previous contents are deleted.
   1673      * @return          A reference to 'result'.
   1674      * @see applyPattern
   1675      * @stable ICU 2.0
   1676      */
   1677     virtual UnicodeString& toLocalizedPattern(UnicodeString& result) const;
   1678 
   1679     /**
   1680      * Apply the given pattern to this Format object.  A pattern is a
   1681      * short-hand specification for the various formatting properties.
   1682      * These properties can also be changed individually through the
   1683      * various setter methods.
   1684      * <P>
   1685      * There is no limit to integer digits are set
   1686      * by this routine, since that is the typical end-user desire;
   1687      * use setMaximumInteger if you want to set a real value.
   1688      * For negative numbers, use a second pattern, separated by a semicolon
   1689      * <pre>
   1690      * .      Example "#,#00.0#" -> 1,234.56
   1691      * </pre>
   1692      * This means a minimum of 2 integer digits, 1 fraction digit, and
   1693      * a maximum of 2 fraction digits.
   1694      * <pre>
   1695      * .      Example: "#,#00.0#;(#,#00.0#)" for negatives in parantheses.
   1696      * </pre>
   1697      * In negative patterns, the minimum and maximum counts are ignored;
   1698      * these are presumed to be set in the positive pattern.
   1699      *
   1700      * @param pattern    The pattern to be applied.
   1701      * @param parseError Struct to recieve information on position
   1702      *                   of error if an error is encountered
   1703      * @param status     Output param set to success/failure code on
   1704      *                   exit. If the pattern is invalid, this will be
   1705      *                   set to a failure result.
   1706      * @stable ICU 2.0
   1707      */
   1708     virtual void applyPattern(const UnicodeString& pattern,
   1709                              UParseError& parseError,
   1710                              UErrorCode& status);
   1711     /**
   1712      * Sets the pattern.
   1713      * @param pattern   The pattern to be applied.
   1714      * @param status    Output param set to success/failure code on
   1715      *                  exit. If the pattern is invalid, this will be
   1716      *                  set to a failure result.
   1717      * @stable ICU 2.0
   1718      */
   1719     virtual void applyPattern(const UnicodeString& pattern,
   1720                              UErrorCode& status);
   1721 
   1722     /**
   1723      * Apply the given pattern to this Format object.  The pattern
   1724      * is assumed to be in a localized notation. A pattern is a
   1725      * short-hand specification for the various formatting properties.
   1726      * These properties can also be changed individually through the
   1727      * various setter methods.
   1728      * <P>
   1729      * There is no limit to integer digits are set
   1730      * by this routine, since that is the typical end-user desire;
   1731      * use setMaximumInteger if you want to set a real value.
   1732      * For negative numbers, use a second pattern, separated by a semicolon
   1733      * <pre>
   1734      * .      Example "#,#00.0#" -> 1,234.56
   1735      * </pre>
   1736      * This means a minimum of 2 integer digits, 1 fraction digit, and
   1737      * a maximum of 2 fraction digits.
   1738      *
   1739      * Example: "#,#00.0#;(#,#00.0#)" for negatives in parantheses.
   1740      *
   1741      * In negative patterns, the minimum and maximum counts are ignored;
   1742      * these are presumed to be set in the positive pattern.
   1743      *
   1744      * @param pattern   The localized pattern to be applied.
   1745      * @param parseError Struct to recieve information on position
   1746      *                   of error if an error is encountered
   1747      * @param status    Output param set to success/failure code on
   1748      *                  exit. If the pattern is invalid, this will be
   1749      *                  set to a failure result.
   1750      * @stable ICU 2.0
   1751      */
   1752     virtual void applyLocalizedPattern(const UnicodeString& pattern,
   1753                                        UParseError& parseError,
   1754                                        UErrorCode& status);
   1755 
   1756     /**
   1757      * Apply the given pattern to this Format object.
   1758      *
   1759      * @param pattern   The localized pattern to be applied.
   1760      * @param status    Output param set to success/failure code on
   1761      *                  exit. If the pattern is invalid, this will be
   1762      *                  set to a failure result.
   1763      * @stable ICU 2.0
   1764      */
   1765     virtual void applyLocalizedPattern(const UnicodeString& pattern,
   1766                                        UErrorCode& status);
   1767 
   1768 
   1769     /**
   1770      * Sets the maximum number of digits allowed in the integer portion of a
   1771      * number. This override limits the integer digit count to 309.
   1772      *
   1773      * @param newValue    the new value of the maximum number of digits
   1774      *                      allowed in the integer portion of a number.
   1775      * @see NumberFormat#setMaximumIntegerDigits
   1776      * @stable ICU 2.0
   1777      */
   1778     virtual void setMaximumIntegerDigits(int32_t newValue);
   1779 
   1780     /**
   1781      * Sets the minimum number of digits allowed in the integer portion of a
   1782      * number. This override limits the integer digit count to 309.
   1783      *
   1784      * @param newValue    the new value of the minimum number of digits
   1785      *                      allowed in the integer portion of a number.
   1786      * @see NumberFormat#setMinimumIntegerDigits
   1787      * @stable ICU 2.0
   1788      */
   1789     virtual void setMinimumIntegerDigits(int32_t newValue);
   1790 
   1791     /**
   1792      * Sets the maximum number of digits allowed in the fraction portion of a
   1793      * number. This override limits the fraction digit count to 340.
   1794      *
   1795      * @param newValue    the new value of the maximum number of digits
   1796      *                    allowed in the fraction portion of a number.
   1797      * @see NumberFormat#setMaximumFractionDigits
   1798      * @stable ICU 2.0
   1799      */
   1800     virtual void setMaximumFractionDigits(int32_t newValue);
   1801 
   1802     /**
   1803      * Sets the minimum number of digits allowed in the fraction portion of a
   1804      * number. This override limits the fraction digit count to 340.
   1805      *
   1806      * @param newValue    the new value of the minimum number of digits
   1807      *                    allowed in the fraction portion of a number.
   1808      * @see NumberFormat#setMinimumFractionDigits
   1809      * @stable ICU 2.0
   1810      */
   1811     virtual void setMinimumFractionDigits(int32_t newValue);
   1812 
   1813     /**
   1814      * Returns the minimum number of significant digits that will be
   1815      * displayed. This value has no effect unless areSignificantDigitsUsed()
   1816      * returns true.
   1817      * @return the fewest significant digits that will be shown
   1818      * @stable ICU 3.0
   1819      */
   1820     int32_t getMinimumSignificantDigits() const;
   1821 
   1822     /**
   1823      * Returns the maximum number of significant digits that will be
   1824      * displayed. This value has no effect unless areSignificantDigitsUsed()
   1825      * returns true.
   1826      * @return the most significant digits that will be shown
   1827      * @stable ICU 3.0
   1828      */
   1829     int32_t getMaximumSignificantDigits() const;
   1830 
   1831     /**
   1832      * Sets the minimum number of significant digits that will be
   1833      * displayed.  If <code>min</code> is less than one then it is set
   1834      * to one.  If the maximum significant digits count is less than
   1835      * <code>min</code>, then it is set to <code>min</code>.
   1836      * This function also enables the use of significant digits
   1837      * by this formatter - areSignificantDigitsUsed() will return TRUE.
   1838      * @see #areSignificantDigitsUsed
   1839      * @param min the fewest significant digits to be shown
   1840      * @stable ICU 3.0
   1841      */
   1842     void setMinimumSignificantDigits(int32_t min);
   1843 
   1844     /**
   1845      * Sets the maximum number of significant digits that will be
   1846      * displayed.  If <code>max</code> is less than one then it is set
   1847      * to one.  If the minimum significant digits count is greater
   1848      * than <code>max</code>, then it is set to <code>max</code>.
   1849      * This function also enables the use of significant digits
   1850      * by this formatter - areSignificantDigitsUsed() will return TRUE.
   1851      * @see #areSignificantDigitsUsed
   1852      * @param max the most significant digits to be shown
   1853      * @stable ICU 3.0
   1854      */
   1855     void setMaximumSignificantDigits(int32_t max);
   1856 
   1857     /**
   1858      * Returns true if significant digits are in use, or false if
   1859      * integer and fraction digit counts are in use.
   1860      * @return true if significant digits are in use
   1861      * @stable ICU 3.0
   1862      */
   1863     UBool areSignificantDigitsUsed() const;
   1864 
   1865     /**
   1866      * Sets whether significant digits are in use, or integer and
   1867      * fraction digit counts are in use.
   1868      * @param useSignificantDigits true to use significant digits, or
   1869      * false to use integer and fraction digit counts
   1870      * @stable ICU 3.0
   1871      */
   1872     void setSignificantDigitsUsed(UBool useSignificantDigits);
   1873 
   1874  public:
   1875     /**
   1876      * Sets the currency used to display currency
   1877      * amounts.  This takes effect immediately, if this format is a
   1878      * currency format.  If this format is not a currency format, then
   1879      * the currency is used if and when this object becomes a
   1880      * currency format through the application of a new pattern.
   1881      * @param theCurrency a 3-letter ISO code indicating new currency
   1882      * to use.  It need not be null-terminated.  May be the empty
   1883      * string or NULL to indicate no currency.
   1884      * @param ec input-output error code
   1885      * @stable ICU 3.0
   1886      */
   1887     virtual void setCurrency(const UChar* theCurrency, UErrorCode& ec);
   1888 
   1889     /**
   1890      * Sets the currency used to display currency amounts.  See
   1891      * setCurrency(const UChar*, UErrorCode&).
   1892      * @deprecated ICU 3.0. Use setCurrency(const UChar*, UErrorCode&).
   1893      */
   1894     virtual void setCurrency(const UChar* theCurrency);
   1895 
   1896 #ifndef U_HIDE_DRAFT_API
   1897     /**
   1898      * Sets the <tt>Currency Context</tt> object used to display currency.
   1899      * This takes effect immediately, if this format is a
   1900      * currency format.
   1901      * @param currencyContext new currency context object to use.
   1902      * @draft ICU 54
   1903      */
   1904     void setCurrencyUsage(UCurrencyUsage newUsage, UErrorCode* ec);
   1905 
   1906     /**
   1907      * Returns the <tt>Currency Context</tt> object used to display currency
   1908      * @draft ICU 54
   1909      */
   1910     UCurrencyUsage getCurrencyUsage() const;
   1911 #endif  /* U_HIDE_DRAFT_API */
   1912 
   1913 
   1914 #ifndef U_HIDE_DEPRECATED_API
   1915     /**
   1916      * The resource tags we use to retrieve decimal format data from
   1917      * locale resource bundles.
   1918      * @deprecated ICU 3.4. This string has no public purpose. Please don't use it.
   1919      */
   1920     static const char fgNumberPatterns[];
   1921 #endif  /* U_HIDE_DEPRECATED_API */
   1922 
   1923 #ifndef U_HIDE_INTERNAL_API
   1924     /**
   1925      *  Get a FixedDecimal corresponding to a double as it would be
   1926      *  formatted by this DecimalFormat.
   1927      *  Internal, not intended for public use.
   1928      *  @internal
   1929      */
   1930      FixedDecimal getFixedDecimal(double number, UErrorCode &status) const;
   1931 
   1932     /**
   1933      *  Get a FixedDecimal corresponding to a formattable as it would be
   1934      *  formatted by this DecimalFormat.
   1935      *  Internal, not intended for public use.
   1936      *  @internal
   1937      */
   1938      FixedDecimal getFixedDecimal(const Formattable &number, UErrorCode &status) const;
   1939 
   1940     /**
   1941      *  Get a FixedDecimal corresponding to a DigitList as it would be
   1942      *  formatted by this DecimalFormat. Note: the DigitList may be modified.
   1943      *  Internal, not intended for public use.
   1944      *  @internal
   1945      */
   1946      FixedDecimal getFixedDecimal(DigitList &number, UErrorCode &status) const;
   1947 #endif  /* U_HIDE_INTERNAL_API */
   1948 
   1949 public:
   1950 
   1951     /**
   1952      * Return the class ID for this class.  This is useful only for
   1953      * comparing to a return value from getDynamicClassID().  For example:
   1954      * <pre>
   1955      * .      Base* polymorphic_pointer = createPolymorphicObject();
   1956      * .      if (polymorphic_pointer->getDynamicClassID() ==
   1957      * .          Derived::getStaticClassID()) ...
   1958      * </pre>
   1959      * @return          The class ID for all objects of this class.
   1960      * @stable ICU 2.0
   1961      */
   1962     static UClassID U_EXPORT2 getStaticClassID(void);
   1963 
   1964     /**
   1965      * Returns a unique class ID POLYMORPHICALLY.  Pure virtual override.
   1966      * This method is to implement a simple version of RTTI, since not all
   1967      * C++ compilers support genuine RTTI.  Polymorphic operator==() and
   1968      * clone() methods call this method.
   1969      *
   1970      * @return          The class ID for this object. All objects of a
   1971      *                  given class have the same class ID.  Objects of
   1972      *                  other classes have different class IDs.
   1973      * @stable ICU 2.0
   1974      */
   1975     virtual UClassID getDynamicClassID(void) const;
   1976 
   1977 private:
   1978 
   1979     DecimalFormat(); // default constructor not implemented
   1980 
   1981     int32_t precision() const;
   1982 
   1983     /**
   1984      *   Initialize all fields of a new DecimalFormatter to a safe default value.
   1985      *      Common code for use by constructors.
   1986      */
   1987     void init();
   1988 
   1989     /**
   1990      * Do real work of constructing a new DecimalFormat.
   1991      */
   1992     void construct(UErrorCode&              status,
   1993                    UParseError&             parseErr,
   1994                    const UnicodeString*     pattern = 0,
   1995                    DecimalFormatSymbols*    symbolsToAdopt = 0
   1996                    );
   1997 
   1998     /**
   1999      * Does the real work of generating a pattern.
   2000      *
   2001      * @param result     Output param which will receive the pattern.
   2002      *                   Previous contents are deleted.
   2003      * @param localized  TRUE return localized pattern.
   2004      * @return           A reference to 'result'.
   2005      */
   2006     UnicodeString& toPattern(UnicodeString& result, UBool localized) const;
   2007 
   2008     /**
   2009      * Does the real work of applying a pattern.
   2010      * @param pattern    The pattern to be applied.
   2011      * @param localized  If true, the pattern is localized; else false.
   2012      * @param parseError Struct to recieve information on position
   2013      *                   of error if an error is encountered
   2014      * @param status     Output param set to success/failure code on
   2015      *                   exit. If the pattern is invalid, this will be
   2016      *                   set to a failure result.
   2017      */
   2018     void applyPattern(const UnicodeString& pattern,
   2019                             UBool localized,
   2020                             UParseError& parseError,
   2021                             UErrorCode& status);
   2022 
   2023     /*
   2024      * similar to applyPattern, but without re-gen affix for currency
   2025      */
   2026     void applyPatternInternally(const UnicodeString& pluralCount,
   2027                                 const UnicodeString& pattern,
   2028                                 UBool localized,
   2029                                 UParseError& parseError,
   2030                                 UErrorCode& status);
   2031 
   2032     /*
   2033      * only apply pattern without expand affixes
   2034      */
   2035     void applyPatternWithoutExpandAffix(const UnicodeString& pattern,
   2036                                         UBool localized,
   2037                                         UParseError& parseError,
   2038                                         UErrorCode& status);
   2039 
   2040 
   2041     /*
   2042      * expand affixes (after apply patter) and re-compute fFormatWidth
   2043      */
   2044     void expandAffixAdjustWidth(const UnicodeString* pluralCount);
   2045 
   2046 
   2047     /**
   2048      * Do the work of formatting a number, either a double or a long.
   2049      *
   2050      * @param appendTo       Output parameter to receive result.
   2051      *                       Result is appended to existing contents.
   2052      * @param handler        Records information about field positions.
   2053      * @param digits         the digits to be formatted.
   2054      * @param isInteger      if TRUE format the digits as Integer.
   2055      * @return               Reference to 'appendTo' parameter.
   2056      */
   2057     UnicodeString& subformat(UnicodeString& appendTo,
   2058                              FieldPositionHandler& handler,
   2059                              DigitList&     digits,
   2060                              UBool          isInteger,
   2061                              UErrorCode &status) const;
   2062 
   2063 
   2064     void parse(const UnicodeString& text,
   2065                Formattable& result,
   2066                ParsePosition& pos,
   2067                UChar* currency) const;
   2068 
   2069     enum {
   2070         fgStatusInfinite,
   2071         fgStatusLength      // Leave last in list.
   2072     } StatusFlags;
   2073 
   2074     UBool subparse(const UnicodeString& text,
   2075                    const UnicodeString* negPrefix,
   2076                    const UnicodeString* negSuffix,
   2077                    const UnicodeString* posPrefix,
   2078                    const UnicodeString* posSuffix,
   2079                    UBool complexCurrencyParsing,
   2080                    int8_t type,
   2081                    ParsePosition& parsePosition,
   2082                    DigitList& digits, UBool* status,
   2083                    UChar* currency) const;
   2084 
   2085     // Mixed style parsing for currency.
   2086     // It parses against the current currency pattern
   2087     // using complex affix comparison
   2088     // parses against the currency plural patterns using complex affix comparison,
   2089     // and parses against the current pattern using simple affix comparison.
   2090     UBool parseForCurrency(const UnicodeString& text,
   2091                            ParsePosition& parsePosition,
   2092                            DigitList& digits,
   2093                            UBool* status,
   2094                            UChar* currency) const;
   2095 
   2096     int32_t skipPadding(const UnicodeString& text, int32_t position) const;
   2097 
   2098     int32_t compareAffix(const UnicodeString& input,
   2099                          int32_t pos,
   2100                          UBool isNegative,
   2101                          UBool isPrefix,
   2102                          const UnicodeString* affixPat,
   2103                          UBool complexCurrencyParsing,
   2104                          int8_t type,
   2105                          UChar* currency) const;
   2106 
   2107     static UnicodeString& trimMarksFromAffix(const UnicodeString& affix, UnicodeString& trimmedAffix);
   2108 
   2109     UBool equalWithSignCompatibility(UChar32 lhs, UChar32 rhs) const;
   2110 
   2111     int32_t compareSimpleAffix(const UnicodeString& affix,
   2112                                       const UnicodeString& input,
   2113                                       int32_t pos,
   2114                                       UBool lenient) const;
   2115 
   2116     static int32_t skipPatternWhiteSpace(const UnicodeString& text, int32_t pos);
   2117 
   2118     static int32_t skipUWhiteSpace(const UnicodeString& text, int32_t pos);
   2119 
   2120     static int32_t skipUWhiteSpaceAndMarks(const UnicodeString& text, int32_t pos);
   2121 
   2122     static int32_t skipBidiMarks(const UnicodeString& text, int32_t pos);
   2123 
   2124     int32_t compareComplexAffix(const UnicodeString& affixPat,
   2125                                 const UnicodeString& input,
   2126                                 int32_t pos,
   2127                                 int8_t type,
   2128                                 UChar* currency) const;
   2129 
   2130     static int32_t match(const UnicodeString& text, int32_t pos, UChar32 ch);
   2131 
   2132     static int32_t match(const UnicodeString& text, int32_t pos, const UnicodeString& str);
   2133 
   2134     static UBool matchSymbol(const UnicodeString &text, int32_t position, int32_t length, const UnicodeString &symbol,
   2135                              UnicodeSet *sset, UChar32 schar);
   2136 
   2137     static UBool matchDecimal(UChar32 symbolChar,
   2138                             UBool sawDecimal,  UChar32 sawDecimalChar,
   2139                              const UnicodeSet *sset, UChar32 schar);
   2140 
   2141     static UBool matchGrouping(UChar32 groupingChar,
   2142                             UBool sawGrouping, UChar32 sawGroupingChar,
   2143                              const UnicodeSet *sset,
   2144                              UChar32 decimalChar, const UnicodeSet *decimalSet,
   2145                              UChar32 schar);
   2146 
   2147     /**
   2148      * Get a decimal format symbol.
   2149      * Returns a const reference to the symbol string.
   2150      * @internal
   2151      */
   2152     inline const UnicodeString &getConstSymbol(DecimalFormatSymbols::ENumberFormatSymbol symbol) const;
   2153 
   2154     int32_t appendAffix(UnicodeString& buf,
   2155                         double number,
   2156                         FieldPositionHandler& handler,
   2157                         UBool isNegative,
   2158                         UBool isPrefix) const;
   2159 
   2160     /**
   2161      * Append an affix to the given UnicodeString, using quotes if
   2162      * there are special characters.  Single quotes themselves must be
   2163      * escaped in either case.
   2164      */
   2165     void appendAffixPattern(UnicodeString& appendTo, const UnicodeString& affix,
   2166                             UBool localized) const;
   2167 
   2168     void appendAffixPattern(UnicodeString& appendTo,
   2169                             const UnicodeString* affixPattern,
   2170                             const UnicodeString& expAffix, UBool localized) const;
   2171 
   2172     void expandAffix(const UnicodeString& pattern,
   2173                      UnicodeString& affix,
   2174                      double number,
   2175                      FieldPositionHandler& handler,
   2176                      UBool doFormat,
   2177                      const UnicodeString* pluralCount) const;
   2178 
   2179     void expandAffixes(const UnicodeString* pluralCount);
   2180 
   2181     void addPadding(UnicodeString& appendTo,
   2182                     FieldPositionHandler& handler,
   2183                     int32_t prefixLen, int32_t suffixLen) const;
   2184 
   2185     UBool isGroupingPosition(int32_t pos) const;
   2186 
   2187     void setCurrencyForSymbols();
   2188 
   2189     // similar to setCurrency without re-compute the affixes for currency.
   2190     // If currency changes, the affix pattern for currency is not changed,
   2191     // but the affix will be changed. So, affixes need to be
   2192     // re-computed in setCurrency(), but not in setCurrencyInternally().
   2193     virtual void setCurrencyInternally(const UChar* theCurrency, UErrorCode& ec);
   2194 
   2195     // set up currency affix patterns for mix parsing.
   2196     // The patterns saved here are the affix patterns of default currency
   2197     // pattern and the unique affix patterns of the plural currency patterns.
   2198     // Those patterns are used by parseForCurrency().
   2199     void setupCurrencyAffixPatterns(UErrorCode& status);
   2200 
   2201     // set up the currency affixes used in currency plural formatting.
   2202     // It sets up both fAffixesForCurrency for currency pattern if the current
   2203     // pattern contains 3 currency signs,
   2204     // and it sets up fPluralAffixesForCurrency for currency plural patterns.
   2205     void setupCurrencyAffixes(const UnicodeString& pattern,
   2206                               UBool setupForCurrentPattern,
   2207                               UBool setupForPluralPattern,
   2208                               UErrorCode& status);
   2209 
   2210     // get the currency rounding with respect to currency usage
   2211     double getCurrencyRounding(const UChar* currency,
   2212                                UErrorCode* ec) const;
   2213 
   2214     // get the currency fraction with respect to currency usage
   2215     int getCurrencyFractionDigits(const UChar* currency,
   2216                                   UErrorCode* ec) const;
   2217 
   2218     // hashtable operations
   2219     Hashtable* initHashForAffixPattern(UErrorCode& status);
   2220     Hashtable* initHashForAffix(UErrorCode& status);
   2221 
   2222     void deleteHashForAffixPattern();
   2223     void deleteHashForAffix(Hashtable*& table);
   2224 
   2225     void copyHashForAffixPattern(const Hashtable* source,
   2226                                  Hashtable* target, UErrorCode& status);
   2227     void copyHashForAffix(const Hashtable* source,
   2228                           Hashtable* target, UErrorCode& status);
   2229 
   2230     UnicodeString& _format(int64_t number,
   2231                            UnicodeString& appendTo,
   2232                            FieldPositionHandler& handler,
   2233                            UErrorCode &status) const;
   2234     UnicodeString& _format(double number,
   2235                            UnicodeString& appendTo,
   2236                            FieldPositionHandler& handler,
   2237                            UErrorCode &status) const;
   2238     UnicodeString& _format(const DigitList &number,
   2239                            UnicodeString& appendTo,
   2240                            FieldPositionHandler& handler,
   2241                            UErrorCode &status) const;
   2242 
   2243     /**
   2244      * Constants.
   2245      */
   2246 
   2247     UnicodeString           fPositivePrefix;
   2248     UnicodeString           fPositiveSuffix;
   2249     UnicodeString           fNegativePrefix;
   2250     UnicodeString           fNegativeSuffix;
   2251     UnicodeString*          fPosPrefixPattern;
   2252     UnicodeString*          fPosSuffixPattern;
   2253     UnicodeString*          fNegPrefixPattern;
   2254     UnicodeString*          fNegSuffixPattern;
   2255 
   2256     /**
   2257      * Formatter for ChoiceFormat-based currency names.  If this field
   2258      * is not null, then delegate to it to format currency symbols.
   2259      * @since ICU 2.6
   2260      */
   2261     ChoiceFormat*           fCurrencyChoice;
   2262 
   2263     DigitList *             fMultiplier;   // NULL for multiplier of one
   2264     int32_t                 fScale;
   2265     int32_t                 fGroupingSize;
   2266     int32_t                 fGroupingSize2;
   2267     UBool                   fDecimalSeparatorAlwaysShown;
   2268     DecimalFormatSymbols*   fSymbols;
   2269 
   2270     UBool                   fUseSignificantDigits;
   2271     int32_t                 fMinSignificantDigits;
   2272     int32_t                 fMaxSignificantDigits;
   2273 
   2274     UBool                   fUseExponentialNotation;
   2275     int8_t                  fMinExponentDigits;
   2276     UBool                   fExponentSignAlwaysShown;
   2277 
   2278     EnumSet<UNumberFormatAttribute,
   2279             UNUM_MAX_NONBOOLEAN_ATTRIBUTE+1,
   2280             UNUM_LIMIT_BOOLEAN_ATTRIBUTE>
   2281                             fBoolFlags;
   2282 
   2283     DigitList*              fRoundingIncrement;  // NULL if no rounding increment specified.
   2284     ERoundingMode           fRoundingMode;
   2285 
   2286     UChar32                 fPad;
   2287     int32_t                 fFormatWidth;
   2288     EPadPosition            fPadPosition;
   2289 
   2290     /*
   2291      * Following are used for currency format
   2292      */
   2293     // pattern used in this formatter
   2294     UnicodeString fFormatPattern;
   2295     // style is only valid when decimal formatter is constructed by
   2296     // DecimalFormat(pattern, decimalFormatSymbol, style)
   2297     int fStyle;
   2298     /*
   2299      * Represents whether this is a currency format, and which
   2300      * currency format style.
   2301      * 0: not currency format type;
   2302      * 1: currency style -- symbol name, such as "$" for US dollar.
   2303      * 2: currency style -- ISO name, such as USD for US dollar.
   2304      * 3: currency style -- plural long name, such as "US Dollar" for
   2305      *                      "1.00 US Dollar", or "US Dollars" for
   2306      *                      "3.00 US Dollars".
   2307      */
   2308     int fCurrencySignCount;
   2309 
   2310 
   2311     /* For currency parsing purose,
   2312      * Need to remember all prefix patterns and suffix patterns of
   2313      * every currency format pattern,
   2314      * including the pattern of default currecny style
   2315      * and plural currency style. And the patterns are set through applyPattern.
   2316      */
   2317     // TODO: innerclass?
   2318     /* This is not needed in the class declaration, so it is moved into decimfmp.cpp
   2319     struct AffixPatternsForCurrency : public UMemory {
   2320         // negative prefix pattern
   2321         UnicodeString negPrefixPatternForCurrency;
   2322         // negative suffix pattern
   2323         UnicodeString negSuffixPatternForCurrency;
   2324         // positive prefix pattern
   2325         UnicodeString posPrefixPatternForCurrency;
   2326         // positive suffix pattern
   2327         UnicodeString posSuffixPatternForCurrency;
   2328         int8_t patternType;
   2329 
   2330         AffixPatternsForCurrency(const UnicodeString& negPrefix,
   2331                                  const UnicodeString& negSuffix,
   2332                                  const UnicodeString& posPrefix,
   2333                                  const UnicodeString& posSuffix,
   2334                                  int8_t type) {
   2335             negPrefixPatternForCurrency = negPrefix;
   2336             negSuffixPatternForCurrency = negSuffix;
   2337             posPrefixPatternForCurrency = posPrefix;
   2338             posSuffixPatternForCurrency = posSuffix;
   2339             patternType = type;
   2340         }
   2341     };
   2342     */
   2343 
   2344     /* affix for currency formatting when the currency sign in the pattern
   2345      * equals to 3, such as the pattern contains 3 currency sign or
   2346      * the formatter style is currency plural format style.
   2347      */
   2348     /* This is not needed in the class declaration, so it is moved into decimfmp.cpp
   2349     struct AffixesForCurrency : public UMemory {
   2350         // negative prefix
   2351         UnicodeString negPrefixForCurrency;
   2352         // negative suffix
   2353         UnicodeString negSuffixForCurrency;
   2354         // positive prefix
   2355         UnicodeString posPrefixForCurrency;
   2356         // positive suffix
   2357         UnicodeString posSuffixForCurrency;
   2358 
   2359         int32_t formatWidth;
   2360 
   2361         AffixesForCurrency(const UnicodeString& negPrefix,
   2362                            const UnicodeString& negSuffix,
   2363                            const UnicodeString& posPrefix,
   2364                            const UnicodeString& posSuffix) {
   2365             negPrefixForCurrency = negPrefix;
   2366             negSuffixForCurrency = negSuffix;
   2367             posPrefixForCurrency = posPrefix;
   2368             posSuffixForCurrency = posSuffix;
   2369         }
   2370     };
   2371     */
   2372 
   2373     // Affix pattern set for currency.
   2374     // It is a set of AffixPatternsForCurrency,
   2375     // each element of the set saves the negative prefix pattern,
   2376     // negative suffix pattern, positive prefix pattern,
   2377     // and positive suffix  pattern of a pattern.
   2378     // It is used for currency mixed style parsing.
   2379     // It is actually is a set.
   2380     // The set contains the default currency pattern from the locale,
   2381     // and the currency plural patterns.
   2382     // Since it is a set, it does not contain duplicated items.
   2383     // For example, if 2 currency plural patterns are the same, only one pattern
   2384     // is included in the set. When parsing, we do not check whether the plural
   2385     // count match or not.
   2386     Hashtable* fAffixPatternsForCurrency;
   2387 
   2388     // Following 2 are affixes for currency.
   2389     // It is a hash map from plural count to AffixesForCurrency.
   2390     // AffixesForCurrency saves the negative prefix,
   2391     // negative suffix, positive prefix, and positive suffix of a pattern.
   2392     // It is used during currency formatting only when the currency sign count
   2393     // is 3. In which case, the affixes are getting from here, not
   2394     // from the fNegativePrefix etc.
   2395     Hashtable* fAffixesForCurrency;  // for current pattern
   2396     Hashtable* fPluralAffixesForCurrency;  // for plural pattern
   2397 
   2398     // Information needed for DecimalFormat to format/parse currency plural.
   2399     CurrencyPluralInfo* fCurrencyPluralInfo;
   2400 
   2401 #if UCONFIG_HAVE_PARSEALLINPUT
   2402     UNumberFormatAttributeValue fParseAllInput;
   2403 #endif
   2404 
   2405     // Decimal Format Static Sets singleton.
   2406     const DecimalFormatStaticSets *fStaticSets;
   2407 
   2408     // Currency Usage(STANDARD vs CASH)
   2409     UCurrencyUsage fCurrencyUsage;
   2410 
   2411 protected:
   2412 
   2413 #ifndef U_HIDE_INTERNAL_API
   2414     /**
   2415      * Rounds a value according to the rules of this object.
   2416      * @internal
   2417      */
   2418     DigitList& _round(const DigitList& number, DigitList& adjustedNum, UBool& isNegative, UErrorCode& status) const;
   2419 #endif  /* U_HIDE_INTERNAL_API */
   2420 
   2421     /**
   2422      * Returns the currency in effect for this formatter.  Subclasses
   2423      * should override this method as needed.  Unlike getCurrency(),
   2424      * this method should never return "".
   2425      * @result output parameter for null-terminated result, which must
   2426      * have a capacity of at least 4
   2427      * @internal
   2428      */
   2429     virtual void getEffectiveCurrency(UChar* result, UErrorCode& ec) const;
   2430 
   2431   /** number of integer digits
   2432    * @stable ICU 2.4
   2433    */
   2434     static const int32_t  kDoubleIntegerDigits;
   2435   /** number of fraction digits
   2436    * @stable ICU 2.4
   2437    */
   2438     static const int32_t  kDoubleFractionDigits;
   2439 
   2440     /**
   2441      * When someone turns on scientific mode, we assume that more than this
   2442      * number of digits is due to flipping from some other mode that didn't
   2443      * restrict the maximum, and so we force 1 integer digit.  We don't bother
   2444      * to track and see if someone is using exponential notation with more than
   2445      * this number, it wouldn't make sense anyway, and this is just to make sure
   2446      * that someone turning on scientific mode with default settings doesn't
   2447      * end up with lots of zeroes.
   2448      * @stable ICU 2.8
   2449      */
   2450     static const int32_t  kMaxScientificIntegerDigits;
   2451 
   2452 #if UCONFIG_FORMAT_FASTPATHS_49
   2453  private:
   2454     /**
   2455      * Internal state.
   2456      * @internal
   2457      */
   2458     uint8_t fReserved[UNUM_DECIMALFORMAT_INTERNAL_SIZE];
   2459 
   2460 
   2461     /**
   2462      * Called whenever any state changes. Recomputes whether fastpath is OK to use.
   2463      */
   2464     void handleChanged();
   2465 #endif
   2466 };
   2467 
   2468 inline const UnicodeString &
   2469 DecimalFormat::getConstSymbol(DecimalFormatSymbols::ENumberFormatSymbol symbol) const {
   2470     return fSymbols->getConstSymbol(symbol);
   2471 }
   2472 
   2473 U_NAMESPACE_END
   2474 
   2475 #endif /* #if !UCONFIG_NO_FORMATTING */
   2476 
   2477 #endif // _DECIMFMT
   2478 //eof
   2479