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