/**
 * Currently, getDouble() depends on atof() 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
{
    // TODO:  fix thread safety.  Can probably be finessed some by analyzing
    //        what public const functions can see which DigitLists.
    //        Like precompute fDouble for DigitLists coming in from a parse
    //        or from a Formattable::set(), but not for any others.
    if (fHaveDouble) {
        return fDouble;
    }
    DigitList *nonConstThis = const_cast<DigitList *>(this);

    if (isZero()) {
        nonConstThis->fDouble = 0.0;
        if (decNumberIsNegative(fDecNumber)) {
            nonConstThis->fDouble /= -1;
        }
    } else if (isInfinite()) {
        if (std::numeric_limits<double>::has_infinity) {
            nonConstThis->fDouble = std::numeric_limits<double>::infinity();
        } else {
            nonConstThis->fDouble = std::numeric_limits<double>::max();
        }
        if (!isPositive()) {
            nonConstThis->fDouble = -fDouble;
        } 
    } 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);
        
        loadDecimalChar();
        if (gDecimal != '.') {
            char *decimalPt = strchr(s, '.');
            if (decimalPt != NULL) {
                *decimalPt = gDecimal;
            }
        }
        char *end = NULL;
        nonConstThis->fDouble = uprv_strtod(s, &end);
    }
    nonConstThis->fHaveDouble = TRUE;
    return fDouble;
}
/**
 * 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;
}
Exemple #3
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void DigitList::getDecimal(DecimalNumberString &str, UErrorCode &status) {
    if (U_FAILURE(status)) {
        return;
    }
    
    // A decimal number in string form can, worst case, be 14 characters longer
    //  than the number of digits.  So says the decNumber library doc.
    int32_t maxLength = fDecNumber->digits + 15;
    str.setLength(maxLength, status);
    if (U_FAILURE(status)) {
        return;    // Memory allocation error on growing the string.
    }
    uprv_decNumberToString(this->fDecNumber, &str[0]);
    int32_t len = uprv_strlen(&str[0]);
    U_ASSERT(len <= maxLength);
    str.setLength(len, status);
}
/**
 *  Return a string form of this number.
 *     Format is as defined by the decNumber library, for interchange of
 *     decimal numbers.
 */
void DigitList::getDecimal(CharString &str, UErrorCode &status) {
    if (U_FAILURE(status)) {
        return;
    }

    // A decimal number in string form can, worst case, be 14 characters longer
    //  than the number of digits.  So says the decNumber library doc.
    int32_t maxLength = fDecNumber->digits + 14;
    int32_t capacity = 0;
    char *buffer = str.clear().getAppendBuffer(maxLength, 0, capacity, status);
    if (U_FAILURE(status)) {
        return;    // Memory allocation error on growing the string.
    }
    U_ASSERT(capacity >= maxLength);
    uprv_decNumberToString(this->fDecNumber, buffer);
    U_ASSERT((int32_t)uprv_strlen(buffer) <= maxLength);
    str.append(buffer, -1, status);
}
/**
 * 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;
}