C++ DigitList类代码示例

VisibleDigits &
FixedPrecision::initVisibleDigits(
        int64_t value,
        VisibleDigits &digits,
        UErrorCode &status) const {
    if (U_FAILURE(status)) {
        return digits;
    }
    if (!fRoundingIncrement.isZero()) {
        // If we have round increment, use digit list.
        DigitList digitList;
        digitList.set(value);
        return initVisibleDigits(digitList, digits, status);
    }
    // Try fast path
    if (initVisibleDigits(value, 0, digits, status)) {
        digits.fAbsDoubleValue = fabs((double) value);
        digits.fAbsDoubleValueSet = U_SUCCESS(status) && !digits.isOverMaxDigits();
        return digits;
    }
    // Oops have to use digit list
    DigitList digitList;
    digitList.set(value);
    return initVisibleDigits(digitList, digits, status);
}

// ---------------------------------------
void
Formattable::setDecimalNumber(StringPiece numberString, UErrorCode &status) {
    if (U_FAILURE(status)) {
        return;
    }
    dispose();

    // Copy the input string and nul-terminate it.
    //    The decNumber library requires nul-terminated input.  StringPiece input
    //    is not guaranteed nul-terminated.  Too bad.
    //    CharString automatically adds the nul.
    DigitList *dnum = new DigitList(); // TODO: use getInternalDigitList
    if (dnum == NULL) {
        status = U_MEMORY_ALLOCATION_ERROR;
        return;
    }
    dnum->set(CharString(numberString, status).toStringPiece(), status);
    if (U_FAILURE(status)) {
        delete dnum;
        return;   // String didn't contain a decimal number.
    }
    adoptDigitList(dnum);

    // Note that we do not hang on to the caller's input string.
    // If we are asked for the string, we will regenerate one from fDecimalNum.
}

/**
 * Currently, getDouble() depends on strtod() to do its conversion.
 *
 * WARNING!!
 * This is an extremely costly function. ~1/2 of the conversion time
 * can be linked to this function.
 */
double
DigitList::getDouble() const
{
    {
        Mutex mutex;
        if (fHave == kDouble) {
            return fUnion.fDouble;
        }
    }

    double tDouble = 0.0;
    if (isZero()) {
        tDouble = 0.0;
        if (decNumberIsNegative(fDecNumber)) {
            tDouble /= -1;
        }
    } else if (isInfinite()) {
        if (std::numeric_limits<double>::has_infinity) {
            tDouble = std::numeric_limits<double>::infinity();
        } else {
            tDouble = std::numeric_limits<double>::max();
        }
        if (!isPositive()) {
            tDouble = -tDouble; //this was incorrectly "-fDouble" originally.
        }
    } else {
        MaybeStackArray<char, MAX_DBL_DIGITS+18> s;
           // Note:  14 is a  magic constant from the decNumber library documentation,
           //        the max number of extra characters beyond the number of digits
           //        needed to represent the number in string form.  Add a few more
           //        for the additional digits we retain.

        // Round down to appx. double precision, if the number is longer than that.
        // Copy the number first, so that we don't modify the original.
        if (getCount() > MAX_DBL_DIGITS + 3) {
            DigitList numToConvert(*this);
            numToConvert.reduce();    // Removes any trailing zeros, so that digit count is good.
            numToConvert.round(MAX_DBL_DIGITS+3);
            uprv_decNumberToString(numToConvert.fDecNumber, s.getAlias());
            // TODO:  how many extra digits should be included for an accurate conversion?
        } else {
            uprv_decNumberToString(this->fDecNumber, s.getAlias());
        }
        U_ASSERT(uprv_strlen(&s[0]) < MAX_DBL_DIGITS+18);

        char *end = NULL;
        tDouble = decimalStrToDouble(s.getAlias(), &end);
    }
    {
        Mutex mutex;
        DigitList *nonConstThis = const_cast<DigitList *>(this);
        nonConstThis->internalSetDouble(tDouble);
    }
    return tDouble;
}

void
DigitList::mult(const DigitList &other, UErrorCode &status) {
    fContext.status = 0;
    int32_t requiredDigits = this->digits() + other.digits();
    if (requiredDigits > fContext.digits) {
        reduce();    // Remove any trailing zeros
        int32_t requiredDigits = this->digits() + other.digits();
        ensureCapacity(requiredDigits, status);
    }
    uprv_decNumberMultiply(fDecNumber, fDecNumber, other.fDecNumber, &fContext);
    fHaveDouble = FALSE;
}

VisibleDigitsWithExponent &
ScientificPrecision::initVisibleDigitsWithExponent(
        int64_t value,
        VisibleDigitsWithExponent &digits,
        UErrorCode &status) const {
    if (U_FAILURE(status)) {
        return digits;
    }
    DigitList digitList;
    digitList.set(value);
    return initVisibleDigitsWithExponent(digitList, digits, status);
}

void PluralRulesTest::checkSelect(const LocalPointer<PluralRules> &rules, UErrorCode &status, 
                                  int32_t line, const char *keyword, ...) {
    // The varargs parameters are a const char* strings, each being a decimal number.
    //   The formatting of the numbers as strings is significant, e.g.
    //     the difference between "2" and "2.0" can affect which rule matches (which keyword is selected).
    // Note: rules parameter is a LocalPointer reference rather than a PluralRules * to avoid having
    //       to write getAlias() at every (numerous) call site.

    if (U_FAILURE(status)) {
        errln("file %s, line %d, ICU error status: %s.", __FILE__, line, u_errorName(status));
        status = U_ZERO_ERROR;
        return;
    }

    if (rules == NULL) {
        errln("file %s, line %d: rules pointer is NULL", __FILE__, line);
        return;
    }
        
    va_list ap;
    va_start(ap, keyword);
    for (;;) {
        const char *num = va_arg(ap, const char *);
        if (strcmp(num, END_MARK) == 0) {
            break;
        }

        // DigitList is a convenient way to parse the decimal number string and get a double.
        DigitList  dl;
        dl.set(StringPiece(num), status);
        if (U_FAILURE(status)) {
            errln("file %s, line %d, ICU error status: %s.", __FILE__, line, u_errorName(status));
            status = U_ZERO_ERROR;
            continue;
        }
        double numDbl = dl.getDouble();
        const char *decimalPoint = strchr(num, '.');
        int fractionDigitCount = decimalPoint == NULL ? 0 : (num + strlen(num) - 1) - decimalPoint;
        int fractionDigits = fractionDigitCount == 0 ? 0 : atoi(decimalPoint + 1);
        FixedDecimal ni(numDbl, fractionDigitCount, fractionDigits);
        
        UnicodeString actualKeyword = rules->select(ni);
        if (actualKeyword != UnicodeString(keyword)) {
            errln("file %s, line %d, select(%s) returned incorrect keyword. Expected %s, got %s",
                   __FILE__, line, num, keyword, US(actualKeyword).cstr());
        }
    }
    va_end(ap);
}

/*
 * Multiply
 *      The number will be expanded if need be to retain full precision.
 *      In practice, for formatting, multiply is by 10, 100 or 1000, so more digits
 *      will not be required for this use.
 */
void
DigitList::mult(const DigitList &other, UErrorCode &status) {
    if (U_FAILURE(status)) {
        return;
    }
    fContext.status = 0;
    int32_t requiredDigits = this->digits() + other.digits();
    if (requiredDigits > fContext.digits) {
        reduce();    // Remove any trailing zeros
        int32_t requiredDigits = this->digits() + other.digits();
        ensureCapacity(requiredDigits, status);
    }
    uprv_decNumberMultiply(fDecNumber, fDecNumber, other.fDecNumber, &fContext);
    internalClear();
}

UBool
FixedPrecision::handleNonNumeric(DigitList &value, VisibleDigits &digits) {
    if (value.isNaN()) {
        digits.setNaN();
        return TRUE;
    }
    if (value.isInfinite()) {
        digits.setInfinite();
        if (!value.isPositive()) {
            digits.setNegative();
        }
        return TRUE;
    }
    return FALSE;
}

/**
 * If in "by digits" mode, fills in the substitution one decimal digit
 * at a time using the rule set containing this substitution.
 * Otherwise, uses the superclass function.
 * @param number The number being formatted
 * @param toInsertInto The string to insert the result of formatting
 * the substitution into
 * @param pos The position of the owning rule's rule text in
 * toInsertInto
 */
void
FractionalPartSubstitution::doSubstitution(double number, UnicodeString& toInsertInto, int32_t _pos) const
{
  // if we're not in "byDigits" mode, just use the inherited
  // doSubstitution() routine
  if (!byDigits) {
    NFSubstitution::doSubstitution(number, toInsertInto, _pos);

    // if we're in "byDigits" mode, transform the value into an integer
    // by moving the decimal point eight places to the right and
    // pulling digits off the right one at a time, formatting each digit
    // as an integer using this substitution's owning rule set
    // (this is slower, but more accurate, than doing it from the
    // other end)
  } else {
    //          int32_t numberToFormat = (int32_t)uprv_round(transformNumber(number) * uprv_pow(10, kMaxDecimalDigits));
    //          // this flag keeps us from formatting trailing zeros.  It starts
    //          // out false because we're pulling from the right, and switches
    //          // to true the first time we encounter a non-zero digit
    //          UBool doZeros = FALSE;
    //          for (int32_t i = 0; i < kMaxDecimalDigits; i++) {
    //              int64_t digit = numberToFormat % 10;
    //              if (digit != 0 || doZeros) {
    //                  if (doZeros && useSpaces) {
    //                      toInsertInto.insert(_pos + getPos(), gSpace);
    //                  }
    //                  doZeros = TRUE;
    //                  getRuleSet()->format(digit, toInsertInto, _pos + getPos());
    //              }
    //              numberToFormat /= 10;
    //          }

    DigitList dl;
    dl.set(number);
    dl.roundFixedPoint(20);     // round to 20 fraction digits.
    dl.reduce();                // Removes any trailing zeros.
    
    UBool pad = FALSE;
    for (int32_t didx = dl.getCount()-1; didx>=dl.getDecimalAt(); didx--) {
      // Loop iterates over fraction digits, starting with the LSD.
      //   include both real digits from the number, and zeros
      //   to the left of the MSD but to the right of the decimal point.
      if (pad && useSpaces) {
        toInsertInto.insert(_pos + getPos(), gSpace);
      } else {
        pad = TRUE;
      }
      int64_t digit = didx>=0 ? dl.getDigit(didx) - '0' : 0;
      getRuleSet()->format(digit, toInsertInto, _pos + getPos());
    }

    if (!pad) {
      // hack around lack of precision in digitlist. if we would end up with
      // "foo point" make sure we add a " zero" to the end.
      getRuleSet()->format((int64_t)0, toInsertInto, _pos + getPos());
    }
  }
}

void
DecimalFormatPatternParser::applyPatternWithoutExpandAffix(
        const UnicodeString& pattern,
        DecimalFormatPattern& out,
        UParseError& parseError,
        UErrorCode& status) {
    if (U_FAILURE(status))
    {
        return;
    }
    out = DecimalFormatPattern();

    // Clear error struct
    parseError.offset = -1;
    parseError.preContext[0] = parseError.postContext[0] = (UChar)0;

    // TODO: Travis Keep: This won't always work.
    UChar nineDigit = (UChar)(fZeroDigit + 9);
    int32_t digitLen = fDigit.length();
    int32_t groupSepLen = fGroupingSeparator.length();
    int32_t decimalSepLen = fDecimalSeparator.length();

    int32_t pos = 0;
    int32_t patLen = pattern.length();
    // Part 0 is the positive pattern.  Part 1, if present, is the negative
    // pattern.
    for (int32_t part=0; part<2 && pos<patLen; ++part) {
        // The subpart ranges from 0 to 4: 0=pattern proper, 1=prefix,
        // 2=suffix, 3=prefix in quote, 4=suffix in quote.  Subpart 0 is
        // between the prefix and suffix, and consists of pattern
        // characters.  In the prefix and suffix, percent, perMill, and
        // currency symbols are recognized and translated.
        int32_t subpart = 1, sub0Start = 0, sub0Limit = 0, sub2Limit = 0;

        // It's important that we don't change any fields of this object
        // prematurely.  We set the following variables for the multiplier,
        // grouping, etc., and then only change the actual object fields if
        // everything parses correctly.  This also lets us register
        // the data from part 0 and ignore the part 1, except for the
        // prefix and suffix.
        UnicodeString prefix;
        UnicodeString suffix;
        int32_t decimalPos = -1;
        int32_t multiplier = 1;
        int32_t digitLeftCount = 0, zeroDigitCount = 0, digitRightCount = 0, sigDigitCount = 0;
        int8_t groupingCount = -1;
        int8_t groupingCount2 = -1;
        int32_t padPos = -1;
        UChar32 padChar = 0;
        int32_t roundingPos = -1;
        DigitList roundingInc;
        int8_t expDigits = -1;
        UBool expSignAlways = FALSE;

        // The affix is either the prefix or the suffix.
        UnicodeString* affix = &prefix;

        int32_t start = pos;
        UBool isPartDone = FALSE;
        UChar32 ch;

        for (; !isPartDone && pos < patLen; ) {
            // Todo: account for surrogate pairs
            ch = pattern.char32At(pos);
            switch (subpart) {
            case 0: // Pattern proper subpart (between prefix & suffix)
                // Process the digits, decimal, and grouping characters.  We
                // record five pieces of information.  We expect the digits
                // to occur in the pattern ####00.00####, and we record the
                // number of left digits, zero (central) digits, and right
                // digits.  The position of the last grouping character is
                // recorded (should be somewhere within the first two blocks
                // of characters), as is the position of the decimal point,
                // if any (should be in the zero digits).  If there is no
                // decimal point, then there should be no right digits.
                if (pattern.compare(pos, digitLen, fDigit) == 0) {
                    if (zeroDigitCount > 0 || sigDigitCount > 0) {
                        ++digitRightCount;
                    } else {
                        ++digitLeftCount;
                    }
                    if (groupingCount >= 0 && decimalPos < 0) {
                        ++groupingCount;
                    }
                    pos += digitLen;
                } else if ((ch >= fZeroDigit && ch <= nineDigit) ||
                           ch == fSigDigit) {
                    if (digitRightCount > 0) {
                        // Unexpected '0'
                        debug("Unexpected '0'")
                        status = U_UNEXPECTED_TOKEN;
                        syntaxError(pattern,pos,parseError);
                        return;
                    }
                    if (ch == fSigDigit) {
                        ++sigDigitCount;
                    } else {
                        if (ch != fZeroDigit && roundingPos < 0) {
                            roundingPos = digitLeftCount + zeroDigitCount;
                        }
//.........这里部分代码省略.........

/**
 * Currently, getDouble() depends on strtod() to do its conversion.
 *
 * WARNING!!
 * This is an extremely costly function. ~1/2 of the conversion time
 * can be linked to this function.
 */
double
DigitList::getDouble() const
{
    static char gDecimal = 0;
    char decimalSeparator;
    {
        Mutex mutex;
        if (fHave == kDouble) {
            return fUnion.fDouble;
        } else if(fHave == kInt64) {
            return (double)fUnion.fInt64;
        }
        decimalSeparator = gDecimal;
    }

    if (decimalSeparator == 0) {
        // We need to know the decimal separator character that will be used with strtod().
        // Depends on the C runtime global locale.
        // Most commonly is '.'
        // TODO: caching could fail if the global locale is changed on the fly.
        char rep[MAX_DIGITS];
        sprintf(rep, "%+1.1f", 1.0);
        decimalSeparator = rep[2];
    }

    double tDouble = 0.0;
    if (isZero()) {
        tDouble = 0.0;
        if (decNumberIsNegative(fDecNumber)) {
            tDouble /= -1;
        }
    } else if (isInfinite()) {
        if (std::numeric_limits<double>::has_infinity) {
            tDouble = std::numeric_limits<double>::infinity();
        } else {
            tDouble = std::numeric_limits<double>::max();
        }
        if (!isPositive()) {
            tDouble = -tDouble; //this was incorrectly "-fDouble" originally.
        } 
    } else {
        MaybeStackArray<char, MAX_DBL_DIGITS+18> s;
           // Note:  14 is a  magic constant from the decNumber library documentation,
           //        the max number of extra characters beyond the number of digits 
           //        needed to represent the number in string form.  Add a few more
           //        for the additional digits we retain.

        // Round down to appx. double precision, if the number is longer than that.
        // Copy the number first, so that we don't modify the original.
        if (getCount() > MAX_DBL_DIGITS + 3) {
            DigitList numToConvert(*this);
            numToConvert.reduce();    // Removes any trailing zeros, so that digit count is good.
            numToConvert.round(MAX_DBL_DIGITS+3);
            uprv_decNumberToString(numToConvert.fDecNumber, s);
            // TODO:  how many extra digits should be included for an accurate conversion?
        } else {
            uprv_decNumberToString(this->fDecNumber, s);
        }
        U_ASSERT(uprv_strlen(&s[0]) < MAX_DBL_DIGITS+18);
        
        if (decimalSeparator != '.') {
            char *decimalPt = strchr(s, '.');
            if (decimalPt != NULL) {
                *decimalPt = decimalSeparator;
            }
        }
        char *end = NULL;
        tDouble = uprv_strtod(s, &end);
    }
    {
        Mutex mutex;
        DigitList *nonConstThis = const_cast<DigitList *>(this);
        nonConstThis->internalSetDouble(tDouble);
        gDecimal = decimalSeparator;
    }
    return tDouble;
}

int32_t
ScientificPrecision::toScientific(DigitList &value) const {
    return value.toScientific(
            fMantissa.fMin.getIntDigitCount(), getMultiplier());
}

UBool
FractionalPartSubstitution::doParse(const UnicodeString& text,
                ParsePosition& parsePosition,
                double baseValue,
                double /*upperBound*/,
                UBool lenientParse,
                Formattable& resVal) const
{
    // if we're not in byDigits mode, we can just use the inherited
    // doParse()
    if (!byDigits) {
        return NFSubstitution::doParse(text, parsePosition, baseValue, 0, lenientParse, resVal);

        // if we ARE in byDigits mode, parse the text one digit at a time
        // using this substitution's owning rule set (we do this by setting
        // upperBound to 10 when calling doParse() ) until we reach
        // nonmatching text
    } else {
        UnicodeString workText(text);
        ParsePosition workPos(1);
        double result = 0;
        int32_t digit;
//          double p10 = 0.1;

        DigitList dl;
        NumberFormat* fmt = NULL;
        while (workText.length() > 0 && workPos.getIndex() != 0) {
            workPos.setIndex(0);
            Formattable temp;
            getRuleSet()->parse(workText, workPos, 10, temp);
            UErrorCode status = U_ZERO_ERROR;
            digit = temp.getLong(status);
//            digit = temp.getType() == Formattable::kLong ?
//               temp.getLong() :
//            (int32_t)temp.getDouble();

            if (lenientParse && workPos.getIndex() == 0) {
                if (!fmt) {
                    status = U_ZERO_ERROR;
                    fmt = NumberFormat::createInstance(status);
                    if (U_FAILURE(status)) {
                        delete fmt;
                        fmt = NULL;
                    }
                }
                if (fmt) {
                    fmt->parse(workText, temp, workPos);
                    digit = temp.getLong(status);
                }
            }

            if (workPos.getIndex() != 0) {
                dl.append((char)('0' + digit));
//                  result += digit * p10;
//                  p10 /= 10;
                parsePosition.setIndex(parsePosition.getIndex() + workPos.getIndex());
                workText.removeBetween(0, workPos.getIndex());
                while (workText.length() > 0 && workText.charAt(0) == gSpace) {
                    workText.removeBetween(0, 1);
                    parsePosition.setIndex(parsePosition.getIndex() + 1);
                }
            }
        }
        delete fmt;

        result = dl.fCount == 0 ? 0 : dl.getDouble();
        result = composeRuleValue(result, baseValue);
        resVal.setDouble(result);
        return TRUE;
    }
}

/**
 * If in "by digits" mode, fills in the substitution one decimal digit
 * at a time using the rule set containing this substitution.
 * Otherwise, uses the superclass function.
 * @param number The number being formatted
 * @param toInsertInto The string to insert the result of formatting
 * the substitution into
 * @param pos The position of the owning rule's rule text in
 * toInsertInto
 */
void
FractionalPartSubstitution::doSubstitution(double number, UnicodeString& toInsertInto, int32_t _pos) const
{
  // if we're not in "byDigits" mode, just use the inherited
  // doSubstitution() routine
  if (!byDigits) {
    NFSubstitution::doSubstitution(number, toInsertInto, _pos);

    // if we're in "byDigits" mode, transform the value into an integer
    // by moving the decimal point eight places to the right and
    // pulling digits off the right one at a time, formatting each digit
    // as an integer using this substitution's owning rule set
    // (this is slower, but more accurate, than doing it from the
    // other end)
  } else {
    //          int32_t numberToFormat = (int32_t)uprv_round(transformNumber(number) * uprv_pow(10, kMaxDecimalDigits));
    //          // this flag keeps us from formatting trailing zeros.  It starts
    //          // out false because we're pulling from the right, and switches
    //          // to true the first time we encounter a non-zero digit
    //          UBool doZeros = FALSE;
    //          for (int32_t i = 0; i < kMaxDecimalDigits; i++) {
    //              int64_t digit = numberToFormat % 10;
    //              if (digit != 0 || doZeros) {
    //                  if (doZeros && useSpaces) {
    //                      toInsertInto.insert(_pos + getPos(), gSpace);
    //                  }
    //                  doZeros = TRUE;
    //                  getRuleSet()->format(digit, toInsertInto, _pos + getPos());
    //              }
    //              numberToFormat /= 10;
    //          }

    DigitList dl;
    dl.set(number, 20, TRUE);
    
    UBool pad = FALSE;
    while (dl.fCount > (dl.fDecimalAt <= 0 ? 0 : dl.fDecimalAt)) {
      if (pad && useSpaces) {
        toInsertInto.insert(_pos + getPos(), gSpace);
      } else {
        pad = TRUE;
      }
      getRuleSet()->format((int64_t)(dl.fDigits[--dl.fCount] - '0'), toInsertInto, _pos + getPos());
    }
    while (dl.fDecimalAt < 0) {
      if (pad && useSpaces) {
        toInsertInto.insert(_pos + getPos(), gSpace);
      } else {
        pad = TRUE;
      }
      getRuleSet()->format((int64_t)0, toInsertInto, _pos + getPos());
      ++dl.fDecimalAt;
    }

    if (!pad) {
      // hack around lack of precision in digitlist. if we would end up with
      // "foo point" make sure we add a " zero" to the end.
      getRuleSet()->format((int64_t)0, toInsertInto, _pos + getPos());
    }
  }
}