/* ****************************************************************************** * * Copyright (C) 1997-2007, International Business Machines * Corporation and others. All Rights Reserved. * ****************************************************************************** * * File DIGITLST.H * * Modification History: * * Date Name Description * 02/25/97 aliu Converted from java. * 03/21/97 clhuang Updated per C++ implementation. * 04/15/97 aliu Changed MAX_COUNT to DBL_DIG. Changed Digit to char. * 09/09/97 aliu Adapted for exponential notation support. * 08/02/98 stephen Added nearest/even rounding * 06/29/99 stephen Made LONG_DIGITS a macro to satisfy SUN compiler * 07/09/99 stephen Removed kMaxCount (unused, for HP compiler) ****************************************************************************** */ #ifndef DIGITLST_H #define DIGITLST_H #include "unicode/uobject.h" #if !UCONFIG_NO_FORMATTING #include "unicode/decimfmt.h" #include <float.h> // Decimal digits in a 64-bit int //#define LONG_DIGITS 19 #define INT64_DIGITS 19 typedef enum EDigitListValues { MAX_DBL_DIGITS = DBL_DIG, MAX_I64_DIGITS = INT64_DIGITS, MAX_DIGITS = MAX_I64_DIGITS, MAX_EXPONENT = DBL_DIG, DIGIT_PADDING = 3, // "+." + fDigits + "e" + fDecimalAt MAX_DEC_DIGITS = MAX_DIGITS + DIGIT_PADDING + MAX_EXPONENT } EDigitListValues; U_NAMESPACE_BEGIN /** * Digit List utility class. Private to DecimalFormat. Handles the transcoding * between numeric values and strings of characters. Only handles * non-negative numbers. The division of labor between DigitList and * DecimalFormat is that DigitList handles the radix 10 representation * issues; DecimalFormat handles the locale-specific issues such as * positive/negative, grouping, decimal point, currency, and so on. * <P> * A DigitList is really a representation of a floating point value. * It may be an integer value; we assume that a double has sufficient * precision to represent all digits of a long. * <P> * The DigitList representation consists of a string of characters, * which are the digits radix 10, from '0' to '9'. It also has a radix * 10 exponent associated with it. The value represented by a DigitList * object can be computed by mulitplying the fraction f, where 0 <= f < 1, * derived by placing all the digits of the list to the right of the * decimal point, by 10^exponent. */ class DigitList : public UMemory { // Declare external to make compiler happy public: DigitList(); ~DigitList(); /* copy constructor * @param DigitList The object to be copied. * @return the newly created object. */ DigitList(const DigitList&); // copy constructor /* assignment operator * @param DigitList The object to be copied. * @return the newly created object. */ DigitList& operator=(const DigitList&); // assignment operator /** * Return true if another object is semantically equal to this one. * @param other The DigitList to be compared for equality * @return true if another object is semantically equal to this one. * return false otherwise. */ UBool operator==(const DigitList& other) const; private: /** * Commented out due to lack of usage and low code coverage. */ inline UBool operator!=(const DigitList& other) const; public: /** * Clears out the digits. * Use before appending them. * Typically, you set a series of digits with append, then at the point * you hit the decimal point, you set myDigitList.fDecimalAt = myDigitList.fCount; * then go on appending digits. */ void clear(void); /** * Appends digits to the list. Ignores all digits beyond the first DBL_DIG, * since they are not significant for either longs or doubles. * @param digit The digit to be appended. */ inline void append(char digit); /** * Utility routine to get the value of the digit list * Returns 0.0 if zero length. * @return the value of the digit list. */ double getDouble(void) /*const*/; /** * Utility routine to get the value of the digit list * Make sure that fitsIntoLong() is called before calling this function. * Returns 0 if zero length. * @return the value of the digit list, return 0 if it is zero length */ int32_t getLong(void) /*const*/; /** * Utility routine to get the value of the digit list * Make sure that fitsIntoInt64() is called before calling this function. * Returns 0 if zero length. * @return the value of the digit list, return 0 if it is zero length */ int64_t getInt64(void) /*const*/; /** * Return true if the number represented by this object can fit into * a long. * @param ignoreNegativeZero True if negative zero is ignored. * @return true if the number represented by this object can fit into * a long, return false otherwise. */ UBool fitsIntoLong(UBool ignoreNegativeZero) /*const*/; /** * Return true if the number represented by this object can fit into * an int64_t. * @param ignoreNegativeZero True if negative zero is ignored. * @return true if the number represented by this object can fit into * a long, return false otherwise. */ UBool fitsIntoInt64(UBool ignoreNegativeZero) /*const*/; /** * Utility routine to set the value of the digit list from a double * Input must be non-negative, and must not be Inf, -Inf, or NaN. * The maximum fraction digits helps us round properly. * @param source The value to be set * @param maximunDigits The maximum number of digits to be shown * @param fixedPoint True if the point is fixed */ void set(double source, int32_t maximumDigits, UBool fixedPoint = TRUE); /** * Utility routine to set the value of the digit list from a long. * If a non-zero maximumDigits is specified, no more than that number of * significant digits will be produced. * @param source The value to be set * @param maximunDigits The maximum number of digits to be shown */ void set(int32_t source, int32_t maximumDigits = 0); /** * Utility routine to set the value of the digit list from an int64. * If a non-zero maximumDigits is specified, no more than that number of * significant digits will be produced. * @param source The value to be set * @param maximunDigits The maximum number of digits to be shown */ void set(int64_t source, int32_t maximumDigits = 0); /** * Return true if this is a representation of zero. * @return true if this is a representation of zero. */ UBool isZero(void) const; /** * Return true if this is a representation of LONG_MIN. You must use * this method to determine if this is so; you cannot check directly, * because a special format is used to handle this. */ // This code is unused. //UBool isLONG_MIN(void) const; public: /** * These data members are intentionally public and can be set directly. *<P> * The value represented is given by placing the decimal point before * fDigits[fDecimalAt]. If fDecimalAt is < 0, then leading zeros between * the decimal point and the first nonzero digit are implied. If fDecimalAt * is > fCount, then trailing zeros between the fDigits[fCount-1] and the * decimal point are implied. * <P> * Equivalently, the represented value is given by f * 10^fDecimalAt. Here * f is a value 0.1 <= f < 1 arrived at by placing the digits in fDigits to * the right of the decimal. * <P> * DigitList is normalized, so if it is non-zero, fDigits[0] is non-zero. We * don't allow denormalized numbers because our exponent is effectively of * unlimited magnitude. The fCount value contains the number of significant * digits present in fDigits[]. * <P> * Zero is represented by any DigitList with fCount == 0 or with each fDigits[i] * for all i <= fCount == '0'. */ int32_t fDecimalAt; int32_t fCount; UBool fIsPositive; char *fDigits; DecimalFormat::ERoundingMode fRoundingMode; private: /* One character before fDigits for the decimal*/ char fDecimalDigits[MAX_DEC_DIGITS + 1]; /** * 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 round(int32_t maximumDigits); UBool shouldRoundUp(int32_t maximumDigits) const; }; // ------------------------------------- // Appends the digit to the digit list if it's not out of scope. // Ignores the digit, otherwise. inline void DigitList::append(char digit) { // Ignore digits which exceed the precision we can represent if (fCount < MAX_DIGITS) fDigits[fCount++] = digit; } #if 0 inline UBool DigitList::operator!=(const DigitList& other) const { return !operator==(other); } #endif U_NAMESPACE_END #endif // #if !UCONFIG_NO_FORMATTING #endif // _DIGITLST //eof