| /* |
| ********************************************************************** |
| * Copyright (C) 1997-2010, International Business Machines |
| * Corporation and others. All Rights Reserved. |
| ********************************************************************** |
| * |
| * File DIGITLST.CPP |
| * |
| * Modification History: |
| * |
| * Date Name Description |
| * 03/21/97 clhuang Converted from java. |
| * 03/21/97 clhuang Implemented with new APIs. |
| * 03/27/97 helena Updated to pass the simple test after code review. |
| * 03/31/97 aliu Moved isLONG_MIN to here, and fixed it. |
| * 04/15/97 aliu Changed MAX_COUNT to DBL_DIG. Changed Digit to char. |
| * Reworked representation by replacing fDecimalAt |
| * with fExponent. |
| * 04/16/97 aliu Rewrote set() and getDouble() to use sprintf/atof |
| * to do digit conversion. |
| * 09/09/97 aliu Modified for exponential notation support. |
| * 08/02/98 stephen Added nearest/even rounding |
| * Fixed bug in fitsIntoLong |
| ****************************************************************************** |
| */ |
| |
| #include "digitlst.h" |
| |
| #if !UCONFIG_NO_FORMATTING |
| #include "unicode/putil.h" |
| #include "charstr.h" |
| #include "cmemory.h" |
| #include "cstring.h" |
| #include "putilimp.h" |
| #include "uassert.h" |
| #include <stdlib.h> |
| #include <limits.h> |
| #include <string.h> |
| #include <stdio.h> |
| #include <limits> |
| |
| // *************************************************************************** |
| // class DigitList |
| // A wrapper onto decNumber. |
| // Used to be standalone. |
| // *************************************************************************** |
| |
| /** |
| * This is the zero digit. The base for the digits returned by getDigit() |
| * Note that it is the platform invariant digit, and is not Unicode. |
| */ |
| #define kZero '0' |
| |
| static char gDecimal = 0; |
| |
| /* Only for 32 bit numbers. Ignore the negative sign. */ |
| static const char LONG_MIN_REP[] = "2147483648"; |
| static const char I64_MIN_REP[] = "9223372036854775808"; |
| |
| |
| U_NAMESPACE_BEGIN |
| |
| // ------------------------------------- |
| // default constructor |
| |
| DigitList::DigitList() |
| { |
| uprv_decContextDefault(&fContext, DEC_INIT_BASE); |
| fContext.traps = 0; |
| uprv_decContextSetRounding(&fContext, DEC_ROUND_HALF_EVEN); |
| fContext.digits = fStorage.getCapacity(); |
| |
| fDecNumber = fStorage.getAlias(); |
| uprv_decNumberZero(fDecNumber); |
| |
| fDouble = 0.0; |
| fHaveDouble = TRUE; |
| } |
| |
| // ------------------------------------- |
| |
| DigitList::~DigitList() |
| { |
| } |
| |
| // ------------------------------------- |
| // copy constructor |
| |
| DigitList::DigitList(const DigitList &other) |
| { |
| fDecNumber = fStorage.getAlias(); |
| *this = other; |
| } |
| |
| |
| // ------------------------------------- |
| // assignment operator |
| |
| DigitList& |
| DigitList::operator=(const DigitList& other) |
| { |
| if (this != &other) |
| { |
| uprv_memcpy(&fContext, &other.fContext, sizeof(decContext)); |
| |
| if (other.fStorage.getCapacity() > fStorage.getCapacity()) { |
| fDecNumber = fStorage.resize(other.fStorage.getCapacity()); |
| } |
| // Always reset the fContext.digits, even if fDecNumber was not reallocated, |
| // because above we copied fContext from other.fContext. |
| fContext.digits = fStorage.getCapacity(); |
| uprv_decNumberCopy(fDecNumber, other.fDecNumber); |
| |
| fDouble = other.fDouble; |
| fHaveDouble = other.fHaveDouble; |
| } |
| return *this; |
| } |
| |
| // ------------------------------------- |
| // operator == (does not exactly match the old DigitList function) |
| |
| UBool |
| DigitList::operator==(const DigitList& that) const |
| { |
| if (this == &that) { |
| return TRUE; |
| } |
| decNumber n; // Has space for only a none digit value. |
| decContext c; |
| uprv_decContextDefault(&c, DEC_INIT_BASE); |
| c.digits = 1; |
| c.traps = 0; |
| |
| uprv_decNumberCompare(&n, this->fDecNumber, that.fDecNumber, &c); |
| UBool result = decNumberIsZero(&n); |
| return result; |
| } |
| |
| // ------------------------------------- |
| // comparison function. Returns |
| // Not Comparable : -2 |
| // < : -1 |
| // == : 0 |
| // > : +1 |
| int32_t DigitList::compare(const DigitList &other) { |
| decNumber result; |
| int32_t savedDigits = fContext.digits; |
| fContext.digits = 1; |
| uprv_decNumberCompare(&result, this->fDecNumber, other.fDecNumber, &fContext); |
| fContext.digits = savedDigits; |
| if (decNumberIsZero(&result)) { |
| return 0; |
| } else if (decNumberIsSpecial(&result)) { |
| return -2; |
| } else if (result.bits & DECNEG) { |
| return -1; |
| } else { |
| return 1; |
| } |
| } |
| |
| |
| // ------------------------------------- |
| // Reduce - remove trailing zero digits. |
| void |
| DigitList::reduce() { |
| uprv_decNumberReduce(fDecNumber, fDecNumber, &fContext); |
| } |
| |
| |
| // ------------------------------------- |
| // trim - remove trailing fraction zero digits. |
| void |
| DigitList::trim() { |
| uprv_decNumberTrim(fDecNumber); |
| } |
| |
| // ------------------------------------- |
| // Resets the digit list; sets all the digits to zero. |
| |
| void |
| DigitList::clear() |
| { |
| uprv_decNumberZero(fDecNumber); |
| uprv_decContextSetRounding(&fContext, DEC_ROUND_HALF_EVEN); |
| fDouble = 0.0; |
| fHaveDouble = TRUE; |
| } |
| |
| |
| /** |
| * Formats a int64_t number into a base 10 string representation, and NULL terminates it. |
| * @param number The number to format |
| * @param outputStr The string to output to. Must be at least MAX_DIGITS+2 in length (21), |
| * to hold the longest int64_t value. |
| * @return the number of digits written, not including the sign. |
| */ |
| static int32_t |
| formatBase10(int64_t number, char *outputStr) { |
| // The number is output backwards, starting with the LSD. |
| // Fill the buffer from the far end. After the number is complete, |
| // slide the string contents to the front. |
| |
| const int32_t MAX_IDX = MAX_DIGITS+2; |
| int32_t destIdx = MAX_IDX; |
| outputStr[--destIdx] = 0; |
| |
| int64_t n = number; |
| if (number < 0) { // Negative numbers are slightly larger than a postive |
| outputStr[--destIdx] = (char)(-(n % 10) + kZero); |
| n /= -10; |
| } |
| do { |
| outputStr[--destIdx] = (char)(n % 10 + kZero); |
| n /= 10; |
| } while (n > 0); |
| |
| if (number < 0) { |
| outputStr[--destIdx] = '-'; |
| } |
| |
| // Slide the number to the start of the output str |
| U_ASSERT(destIdx >= 0); |
| int32_t length = MAX_IDX - destIdx; |
| uprv_memmove(outputStr, outputStr+MAX_IDX-length, length); |
| |
| return length; |
| } |
| |
| |
| // ------------------------------------- |
| |
| void |
| DigitList::setRoundingMode(DecimalFormat::ERoundingMode m) { |
| enum rounding r; |
| |
| switch (m) { |
| case DecimalFormat::kRoundCeiling: r = DEC_ROUND_CEILING; break; |
| case DecimalFormat::kRoundFloor: r = DEC_ROUND_FLOOR; break; |
| case DecimalFormat::kRoundDown: r = DEC_ROUND_DOWN; break; |
| case DecimalFormat::kRoundUp: r = DEC_ROUND_UP; break; |
| case DecimalFormat::kRoundHalfEven: r = DEC_ROUND_HALF_EVEN; break; |
| case DecimalFormat::kRoundHalfDown: r = DEC_ROUND_HALF_DOWN; break; |
| case DecimalFormat::kRoundHalfUp: r = DEC_ROUND_HALF_UP; break; |
| default: |
| // TODO: how to report the problem? |
| // Leave existing mode unchanged. |
| r = uprv_decContextGetRounding(&fContext); |
| } |
| uprv_decContextSetRounding(&fContext, r); |
| |
| } |
| |
| |
| // ------------------------------------- |
| |
| void |
| DigitList::setPositive(UBool s) { |
| if (s) { |
| fDecNumber->bits &= ~DECNEG; |
| } else { |
| fDecNumber->bits |= DECNEG; |
| } |
| fHaveDouble = FALSE; |
| } |
| // ------------------------------------- |
| |
| void |
| DigitList::setDecimalAt(int32_t d) { |
| U_ASSERT((fDecNumber->bits & DECSPECIAL) == 0); // Not Infinity or NaN |
| U_ASSERT(d-1>-999999999); |
| U_ASSERT(d-1< 999999999); |
| int32_t adjustedDigits = fDecNumber->digits; |
| if (decNumberIsZero(fDecNumber)) { |
| // Account for difference in how zero is represented between DigitList & decNumber. |
| adjustedDigits = 0; |
| } |
| fDecNumber->exponent = d - adjustedDigits; |
| fHaveDouble = FALSE; |
| } |
| |
| int32_t |
| DigitList::getDecimalAt() { |
| U_ASSERT((fDecNumber->bits & DECSPECIAL) == 0); // Not Infinity or NaN |
| if (decNumberIsZero(fDecNumber) || ((fDecNumber->bits & DECSPECIAL) != 0)) { |
| return fDecNumber->exponent; // Exponent should be zero for these cases. |
| } |
| return fDecNumber->exponent + fDecNumber->digits; |
| } |
| |
| void |
| DigitList::setCount(int32_t c) { |
| U_ASSERT(c <= fContext.digits); |
| if (c == 0) { |
| // For a value of zero, DigitList sets all fields to zero, while |
| // decNumber keeps one digit (with that digit being a zero) |
| c = 1; |
| fDecNumber->lsu[0] = 0; |
| } |
| fDecNumber->digits = c; |
| fHaveDouble = FALSE; |
| } |
| |
| int32_t |
| DigitList::getCount() const { |
| if (decNumberIsZero(fDecNumber) && fDecNumber->exponent==0) { |
| // The extra test for exponent==0 is needed because parsing sometimes appends |
| // zero digits. It's bogus, decimalFormatter parsing needs to be cleaned up. |
| return 0; |
| } else { |
| return fDecNumber->digits; |
| } |
| } |
| |
| void |
| DigitList::setDigit(int32_t i, char v) { |
| int32_t count = fDecNumber->digits; |
| U_ASSERT(i<count); |
| U_ASSERT(v>='0' && v<='9'); |
| v &= 0x0f; |
| fDecNumber->lsu[count-i-1] = v; |
| fHaveDouble = FALSE; |
| } |
| |
| char |
| DigitList::getDigit(int32_t i) { |
| int32_t count = fDecNumber->digits; |
| U_ASSERT(i<count); |
| return fDecNumber->lsu[count-i-1] + '0'; |
| } |
| |
| // copied from DigitList::getDigit() |
| uint8_t |
| DigitList::getDigitValue(int32_t i) { |
| int32_t count = fDecNumber->digits; |
| U_ASSERT(i<count); |
| return fDecNumber->lsu[count-i-1]; |
| } |
| |
| // ------------------------------------- |
| // Appends the digit to the digit list if it's not out of scope. |
| // Ignores the digit, otherwise. |
| // |
| // This function is horribly inefficient to implement with decNumber because |
| // the digits are stored least significant first, which requires moving all |
| // existing digits down one to make space for the new one to be appended. |
| // |
| void |
| DigitList::append(char digit) |
| { |
| U_ASSERT(digit>='0' && digit<='9'); |
| // Ignore digits which exceed the precision we can represent |
| // And don't fix for larger precision. Fix callers instead. |
| if (decNumberIsZero(fDecNumber)) { |
| // Zero needs to be special cased because of the difference in the way |
| // that the old DigitList and decNumber represent it. |
| // digit cout was zero for digitList, is one for decNumber |
| fDecNumber->lsu[0] = digit & 0x0f; |
| fDecNumber->digits = 1; |
| fDecNumber->exponent--; // To match the old digit list implementation. |
| } else { |
| int32_t nDigits = fDecNumber->digits; |
| if (nDigits < fContext.digits) { |
| int i; |
| for (i=nDigits; i>0; i--) { |
| fDecNumber->lsu[i] = fDecNumber->lsu[i-1]; |
| } |
| fDecNumber->lsu[0] = digit & 0x0f; |
| fDecNumber->digits++; |
| // DigitList emulation - appending doesn't change the magnitude of existing |
| // digits. With decNumber's decimal being after the |
| // least signficant digit, we need to adjust the exponent. |
| fDecNumber->exponent--; |
| } |
| } |
| fHaveDouble = FALSE; |
| } |
| |
| // ------------------------------------- |
| |
| /** |
| * 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 (gDecimal == 0) { |
| char rep[MAX_DIGITS]; |
| // For machines that decide to change the decimal on you, |
| // and try to be too smart with localization. |
| // This normally should be just a '.'. |
| sprintf(rep, "%+1.1f", 1.0); |
| gDecimal = rep[2]; |
| } |
| |
| 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); |
| |
| 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; |
| } |
| |
| // ------------------------------------- |
| |
| /** |
| * convert this number to an int32_t. Round if there is a fractional part. |
| * Return zero if the number cannot be represented. |
| */ |
| int32_t DigitList::getLong() /*const*/ |
| { |
| int32_t result = 0; |
| if (fDecNumber->digits + fDecNumber->exponent > 10) { |
| // Overflow, absolute value too big. |
| return result; |
| } |
| if (fDecNumber->exponent != 0) { |
| // Force to an integer, with zero exponent, rounding if necessary. |
| // (decNumberToInt32 will only work if the exponent is exactly zero.) |
| DigitList copy(*this); |
| DigitList zero; |
| uprv_decNumberQuantize(copy.fDecNumber, copy.fDecNumber, zero.fDecNumber, &fContext); |
| result = uprv_decNumberToInt32(copy.fDecNumber, &fContext); |
| } else { |
| result = uprv_decNumberToInt32(fDecNumber, &fContext); |
| } |
| return result; |
| } |
| |
| |
| /** |
| * convert this number to an int64_t. Round if there is a fractional part. |
| * Return zero if the number cannot be represented. |
| */ |
| int64_t DigitList::getInt64() /*const*/ { |
| // Round if non-integer. (Truncate or round?) |
| // Return 0 if out of range. |
| // Range of in64_t is -9223372036854775808 to 9223372036854775807 (19 digits) |
| // |
| if (fDecNumber->digits + fDecNumber->exponent > 19) { |
| // Overflow, absolute value too big. |
| return 0; |
| } |
| decNumber *workingNum = fDecNumber; |
| |
| if (fDecNumber->exponent != 0) { |
| // Force to an integer, with zero exponent, rounding if necessary. |
| DigitList copy(*this); |
| DigitList zero; |
| uprv_decNumberQuantize(copy.fDecNumber, copy.fDecNumber, zero.fDecNumber, &fContext); |
| workingNum = copy.fDecNumber; |
| } |
| |
| uint64_t value = 0; |
| int32_t numDigits = workingNum->digits; |
| for (int i = numDigits-1; i>=0 ; --i) { |
| int v = workingNum->lsu[i]; |
| value = value * (uint64_t)10 + (uint64_t)v; |
| } |
| if (decNumberIsNegative(workingNum)) { |
| value = ~value; |
| value += 1; |
| } |
| int64_t svalue = (int64_t)value; |
| |
| // Check overflow. It's convenient that the MSD is 9 only on overflow, the amount of |
| // overflow can't wrap too far. The test will also fail -0, but |
| // that does no harm; the right answer is 0. |
| if (numDigits == 19) { |
| if (( decNumberIsNegative(fDecNumber) && svalue>0) || |
| (!decNumberIsNegative(fDecNumber) && svalue<0)) { |
| svalue = 0; |
| } |
| } |
| |
| return svalue; |
| } |
| |
| |
| /** |
| * 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); |
| } |
| |
| /** |
| * Return true if this is an integer value that can be held |
| * by an int32_t type. |
| */ |
| UBool |
| DigitList::fitsIntoLong(UBool ignoreNegativeZero) /*const*/ |
| { |
| if (decNumberIsSpecial(this->fDecNumber)) { |
| // NaN or Infinity. Does not fit in int32. |
| return FALSE; |
| } |
| uprv_decNumberTrim(this->fDecNumber); |
| if (fDecNumber->exponent < 0) { |
| // Number contains fraction digits. |
| return FALSE; |
| } |
| if (decNumberIsZero(this->fDecNumber) && !ignoreNegativeZero && |
| (fDecNumber->bits & DECNEG) != 0) { |
| // Negative Zero, not ingored. Cannot represent as a long. |
| return FALSE; |
| } |
| if (fDecNumber->digits + fDecNumber->exponent < 10) { |
| // The number is 9 or fewer digits. |
| // The max and min int32 are 10 digts, so this number fits. |
| // This is the common case. |
| return TRUE; |
| } |
| |
| // TODO: Should cache these constants; construction is relatively costly. |
| // But not of huge consequence; they're only needed for 10 digit ints. |
| UErrorCode status = U_ZERO_ERROR; |
| DigitList min32; min32.set("-2147483648", status); |
| if (this->compare(min32) < 0) { |
| return FALSE; |
| } |
| DigitList max32; max32.set("2147483647", status); |
| if (this->compare(max32) > 0) { |
| return FALSE; |
| } |
| if (U_FAILURE(status)) { |
| return FALSE; |
| } |
| return true; |
| } |
| |
| |
| |
| /** |
| * Return true if the number represented by this object can fit into |
| * a long. |
| */ |
| UBool |
| DigitList::fitsIntoInt64(UBool ignoreNegativeZero) /*const*/ |
| { |
| if (decNumberIsSpecial(this->fDecNumber)) { |
| // NaN or Infinity. Does not fit in int32. |
| return FALSE; |
| } |
| uprv_decNumberTrim(this->fDecNumber); |
| if (fDecNumber->exponent < 0) { |
| // Number contains fraction digits. |
| return FALSE; |
| } |
| if (decNumberIsZero(this->fDecNumber) && !ignoreNegativeZero && |
| (fDecNumber->bits & DECNEG) != 0) { |
| // Negative Zero, not ingored. Cannot represent as a long. |
| return FALSE; |
| } |
| if (fDecNumber->digits + fDecNumber->exponent < 19) { |
| // The number is 18 or fewer digits. |
| // The max and min int64 are 19 digts, so this number fits. |
| // This is the common case. |
| return TRUE; |
| } |
| |
| // TODO: Should cache these constants; construction is relatively costly. |
| // But not of huge consequence; they're only needed for 19 digit ints. |
| UErrorCode status = U_ZERO_ERROR; |
| DigitList min64; min64.set("-9223372036854775808", status); |
| if (this->compare(min64) < 0) { |
| return FALSE; |
| } |
| DigitList max64; max64.set("9223372036854775807", status); |
| if (this->compare(max64) > 0) { |
| return FALSE; |
| } |
| if (U_FAILURE(status)) { |
| return FALSE; |
| } |
| return true; |
| } |
| |
| |
| // ------------------------------------- |
| |
| void |
| DigitList::set(int32_t source) |
| { |
| set((int64_t)source); |
| fDouble = source; |
| fHaveDouble = TRUE; |
| } |
| |
| // ------------------------------------- |
| /** |
| * @param maximumDigits The maximum digits to be generated. If zero, |
| * there is no maximum -- generate all digits. |
| */ |
| void |
| DigitList::set(int64_t source) |
| { |
| char str[MAX_DIGITS+2]; // Leave room for sign and trailing nul. |
| formatBase10(source, str); |
| U_ASSERT(uprv_strlen(str) < sizeof(str)); |
| |
| uprv_decNumberFromString(fDecNumber, str, &fContext); |
| fDouble = (double)source; |
| fHaveDouble = TRUE; |
| } |
| |
| |
| // ------------------------------------- |
| /** |
| * Set the DigitList from a decimal number string. |
| * |
| * The incoming string _must_ be nul terminated, even though it is arriving |
| * as a StringPiece because that is what the decNumber library wants. |
| * We can get away with this for an internal function; it would not |
| * be acceptable for a public API. |
| */ |
| void |
| DigitList::set(const StringPiece &source, UErrorCode &status) { |
| if (U_FAILURE(status)) { |
| return; |
| } |
| |
| // Figure out a max number of digits to use during the conversion, and |
| // resize the number up if necessary. |
| int32_t numDigits = source.length(); |
| if (numDigits > fContext.digits) { |
| // fContext.digits == fStorage.getCapacity() |
| decNumber *t = fStorage.resize(numDigits, fStorage.getCapacity()); |
| if (t == NULL) { |
| status = U_MEMORY_ALLOCATION_ERROR; |
| return; |
| } |
| fDecNumber = t; |
| fContext.digits = numDigits; |
| } |
| |
| fContext.status = 0; |
| uprv_decNumberFromString(fDecNumber, source.data(), &fContext); |
| if ((fContext.status & DEC_Conversion_syntax) != 0) { |
| status = U_DECIMAL_NUMBER_SYNTAX_ERROR; |
| } |
| fHaveDouble = FALSE; |
| } |
| |
| /** |
| * Set the digit list to a representation of the given double value. |
| * This method supports both fixed-point and exponential notation. |
| * @param source Value to be converted. |
| */ |
| void |
| DigitList::set(double source) |
| { |
| // for now, simple implementation; later, do proper IEEE stuff |
| char rep[MAX_DIGITS + 8]; // Extra space for '+', '.', e+NNN, and '\0' (actually +8 is enough) |
| |
| // Generate a representation of the form /[+-][0-9]+e[+-][0-9]+/ |
| sprintf(rep, "%+1.*e", MAX_DBL_DIGITS - 1, source); |
| U_ASSERT(uprv_strlen(rep) < sizeof(rep)); |
| |
| // Create a decNumber from the string. |
| uprv_decNumberFromString(fDecNumber, rep, &fContext); |
| uprv_decNumberTrim(fDecNumber); |
| fDouble = source; |
| fHaveDouble = TRUE; |
| } |
| |
| // ------------------------------------- |
| |
| /* |
| * 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) { |
| 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; |
| } |
| |
| // ------------------------------------- |
| |
| /* |
| * Divide |
| * The number will _not_ be expanded for inexact results. |
| * TODO: probably should expand some, for rounding increments that |
| * could add a few digits, e.g. .25, but not expand arbitrarily. |
| */ |
| void |
| DigitList::div(const DigitList &other, UErrorCode &status) { |
| if (U_FAILURE(status)) { |
| return; |
| } |
| uprv_decNumberDivide(fDecNumber, fDecNumber, other.fDecNumber, &fContext); |
| fHaveDouble = FALSE; |
| } |
| |
| // ------------------------------------- |
| |
| /* |
| * ensureCapacity. Grow the digit storage for the number if it's less than the requested |
| * amount. Never reduce it. Available size is kept in fContext.digits. |
| */ |
| void |
| DigitList::ensureCapacity(int32_t requestedCapacity, UErrorCode &status) { |
| if (U_FAILURE(status)) { |
| return; |
| } |
| if (requestedCapacity <= 0) { |
| status = U_ILLEGAL_ARGUMENT_ERROR; |
| return; |
| } |
| if (requestedCapacity > DEC_MAX_DIGITS) { |
| // Don't report an error for requesting too much. |
| // Arithemetic Results will be rounded to what can be supported. |
| // At 999,999,999 max digits, exceeding the limit is not too likely! |
| requestedCapacity = DEC_MAX_DIGITS; |
| } |
| if (requestedCapacity > fContext.digits) { |
| decNumber *newBuffer = fStorage.resize(requestedCapacity, fStorage.getCapacity()); |
| if (newBuffer == NULL) { |
| status = U_MEMORY_ALLOCATION_ERROR; |
| return; |
| } |
| fContext.digits = requestedCapacity; |
| fDecNumber = newBuffer; |
| } |
| } |
| |
| // ------------------------------------- |
| |
| /** |
| * Round the representation to the given number of digits. |
| * @param maximumDigits The maximum number of digits to be shown. |
| * Upon return, count will be less than or equal to maximumDigits. |
| */ |
| void |
| DigitList::round(int32_t maximumDigits) |
| { |
| int32_t savedDigits = fContext.digits; |
| fContext.digits = maximumDigits; |
| uprv_decNumberPlus(fDecNumber, fDecNumber, &fContext); |
| fContext.digits = savedDigits; |
| uprv_decNumberTrim(fDecNumber); |
| fHaveDouble = FALSE; |
| } |
| |
| |
| void |
| DigitList::roundFixedPoint(int32_t maximumFractionDigits) { |
| trim(); // Remove trailing zeros. |
| if (fDecNumber->exponent >= -maximumFractionDigits) { |
| return; |
| } |
| decNumber scale; // Dummy decimal number, but with the desired number of |
| uprv_decNumberZero(&scale); // fraction digits. |
| scale.exponent = -maximumFractionDigits; |
| scale.lsu[0] = 1; |
| |
| uprv_decNumberQuantize(fDecNumber, fDecNumber, &scale, &fContext); |
| trim(); |
| fHaveDouble = FALSE; |
| } |
| |
| // ------------------------------------- |
| |
| void |
| DigitList::toIntegralValue() { |
| uprv_decNumberToIntegralValue(fDecNumber, fDecNumber, &fContext); |
| } |
| |
| |
| // ------------------------------------- |
| UBool |
| DigitList::isZero() const |
| { |
| return decNumberIsZero(fDecNumber); |
| } |
| |
| |
| U_NAMESPACE_END |
| #endif // #if !UCONFIG_NO_FORMATTING |
| |
| //eof |
