/*
******************************************************************************
*
* 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();
// BEGIN android-added
/* capacity constructor
* @param capacity The size of the digit list buffer
* @return the newly created object.
*/
DigitList(int capacity);
// END android-added
/* 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;
// BEGIN android-changed
// Public round() method for BigDecimal format.
// Revert this change after ICU4C supports BigDecimal.
/**
* 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);
// END android-changed
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:
// BEGIN android-changed
/* One character before fDigits for the decimal*/
char *fDecimalDigits;
char fDecimalDigitsBuffer[MAX_DEC_DIGITS + 1];
int fBufferSize;
int fMaxDigits; // Max digits can be represented.
// END android-changed
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)
{
// BEGIN android-changed
// Ignore digits which exceed the precision we can represent
if (fCount < fMaxDigits) {
fDigits[fCount++] = digit;
}
// END android-changed
}
#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