Decimal Class Reference

#include <tntdb/decimal.h>

List of all members.

Low level arithmetic methods
template<typename T>
static bool	overflowDetectedInMultiplyByTen (T &n)
template<typename ManType>
static void	divideByPowerOfTen (const ManType dividend, ManType &quotient, ManType &remainder, ManType divisorPowerOfTenDigits) throw (std::overflow_error)
void	init (MantissaType m, ExponentType e, FlagsType f=positive, PrintFlagsType pf=infinityShort)
static void	printFraction (std::ostream &out, ExponentType fracDigits, MantissaType fractional)
	Print fraction.
Public Types
enum	{ Base = 10 }
enum	FlagsTypeEnum {   positive = 0x01,   infinity = 0x02,   negativeInfinity = infinity,   positiveInfinity = infinity | positive,   NaN = 0x04 }
	Flags used for denoting positive or negative, infinity and not a number. More...
enum	InfinityOutputType {   infinityShort,   infinityLong,   infinityTilde }
	How infinity is printed on output. More...
enum	RoundingAlgorithmType {   truncate,   round,   bankersRound }
	Rounding algorithm. More...
typedef uint64_t	MantissaType
typedef int32_t	ExponentType
typedef int8_t	FlagsType
typedef int8_t	PrintFlagsType
Public Member Functions
	Decimal ()
	Initializes the Decimal-object with empty values.
	Decimal (double value)
	Decimal (int64_t man, ExponentType exp)
	Decimal (MantissaType man, ExponentType exp, FlagsType f, PrintFlagsType pf=infinityShort)
MantissaType	getMantissa () const
ExponentType	getExponent () const
bool	isPositive () const
bool	isInfinity () const
bool	isInfinity (bool positiveInfinity) const
bool	isNaN () const
bool	isZero () const
template<typename ManType>
void	getIntegralFractionalExponent (ManType &integral, ManType &fractional, ExponentType &ex, ExponentType optionalUserSpecifiedExponentOffset=0) const throw (std::overflow_error)
template<typename IntegerType>
IntegerType	numberOfDigits (IntegerType n) const
	Return the number of decimal digits in n.
template<typename IntegerType>
IntegerType	getInteger (RoundingAlgorithmType roundingAlgorithm=round) const throw (std::overflow_error)
template<typename FloatingPointType>
FloatingPointType	getFloatingPoint () const
int	getInt () const throw (std::overflow_error)
int32_t	getInt32 () const throw (std::overflow_error)
unsigned	getUnsigned () const throw (std::overflow_error)
uint32_t	getUnsigned32 () const throw (std::overflow_error)
int64_t	getInt64 () const throw (std::overflow_error)
uint64_t	getUnsigned64 () const throw (std::overflow_error)
float	getFloat () const
double	getDouble () const
template<typename IntegerType>
void	setInteger (IntegerType num)
template<typename FloatingPointType>
void	setFloatingPoint (FloatingPointType num)
template<typename IntegerType>
void	setDecimalInteger (IntegerType num, int32_t exponent)
void	setInt (int num)
void	setInt32 (int32_t num)
void	setUnsigned (unsigned num)
void	setUnsigned32 (uint32_t num)
void	setInt64 (int64_t num)
void	setUnsigned64 (uint64_t num)
void	setDecimalInt64 (int64_t num, int32_t exp)
void	setDecimalUnsigned64 (uint64_t num, int32_t exp)
void	setFloat (float num)
void	setDouble (double num)
std::string	toString () const
std::ostream &	print (std::ostream &out) const
std::ostream &	print (std::ostream &out, PrintFlagsType printFlags) const
std::istream &	read (std::istream &in, bool ignoreOverflowReadingFraction=false)

---

Detailed Description

This class holds a decimal floating point number. It is necessary to convert it to some other type to perform arithmetic and other operations. Decimal is implemented with a 64 bit unsigned integer mantissa, and a 32 bit exponent. For conversions from integer types, strings, and reading from the database, Decimal tries to maintain accuracy if the result will fit in the 64 bit unsigned mantissa and exponent. When converting to integer types, Decimal will throw std::overflow exception if the result will not fit. For converting to binary floating point numbers, binary floating point is used in the conversion, and the result is an approximation.

---

Member Enumeration Documentation

enum FlagsTypeEnum

Enumerator:

positive	Set if this Decimal is positive, else this Decimal is negative.
infinity	Set if this Decimal is positive or negative infinity.
negativeInfinity	Negative infinity.
positiveInfinity	Positive infinity.
NaN	Not a Number.

enum InfinityOutputType

Enumerator:

infinityShort	Affects output only, print Inf or -Inf.
infinityLong	Affects output only, print Infinity or -Infinity instead of Inf or -Inf.
infinityTilde	Affects output only, print ~ or -~ (as used in Oracle) instead of Inf or -Inf.

enum RoundingAlgorithmType

Enumerator:

truncate	1.1, 1.5, and 1.6 and all rounded down to 1.0.
round	1.1 is rounded down to 1.0, 1.5, and 1.6 are rounded up to 2.0.
bankersRound	1.1 and 1.5 are rounded down to 1.0, 1.6 is rounded up to 2.0.

---

Constructor & Destructor Documentation

Decimal

(

double

value

)

[explicit]

Initializes the Decimal-object with the given double value.

Parameters:

value

double to initialize it with.

Decimal	(	int64_t	man,
		ExponentType	exp
	)

Initialize this Decimal-object with the given decimal mantissa and exponent.

Parameters:

	man	integer decimal mantissa value to set this Decimal number to.
	exp	integer base 10 exponent to set this Decimal number to.

Decimal	(	MantissaType	man,
		ExponentType	exp,
		FlagsType	f,
		PrintFlagsType	pf = infinityShort
	)

Initializes the Decimal-object with the given MantissaType mantissa and ExponentType exponent

Parameters:

	man	integer decimal mantissa value to set this Decimal number to.
	exp	integer base 10 exponent to set this Decimal number to.
	f	the flags, need to specify positive or negative. Decimal::FlagsTypeEnum
	pf	the print flags for infinity and not a number. Decimal::InfinityOutputType

---

Member Function Documentation

MantissaType getMantissa

(

)

const

Return the decimal mantissa.

Returns:

the decimal mantissa.

ExponentType getExponent

(

)

const

Return the base 10 exponent.

Returns:

the base 10 exponent.

bool isPositive

(

)

const

Is this Decimal number positive?

Returns:

true if this Decimal number is positive, else return false.

References Decimal::positive.

bool isInfinity

(

)

const

Is this Decimal number positive or negative infinity?

Returns:

true if this Decimal number is either positive or negative infinity, else return false.

bool isInfinity

(

bool

positiveInfinity

)

const

Is this Decimal number positive or negative infinity?

Parameters:

positiveInfinity

Returns:

If postitiveInfinity is true, then return true if this Decimal number is postitive infinity. Else if postitiveInfinity is false, then return true if this Decimal number is negative infinity. Else return false.

bool isNaN

(

)

const

Is this Decimal not a number?

Returns:

true if this Decimal number is Not a Number. Else return false.

bool isZero

(

)

const

Is this Decimal number zero?

Returns:

true if this Number object is zero, else return false.

void getIntegralFractionalExponent	(	ManType &	integral,
		ManType &	fractional,
		ExponentType &	ex,
		ExponentType	optionalUserSpecifiedExponentOffset = 0
	)			const throw (std::overflow_error)

Split this decimal number into integral part, fractional and exponent parts. An optional user specified exponent offset can be used to first scale the decimal number.

Parameters:

	integral	the part of the decimal floating point number to the left of the decimal point.
	fractional	the part to the decimal floating point number to the right of the decimal point.
	ex	the exponent of the decimal floating point number
	optionalUserSpecifiedExponentOffset	optional user specified exponent offset can be used to first scale the decimal number.

Exceptions:

std::overflow_error

if the result will not fit

References Decimal::divideByPowerOfTen(), Decimal::overflowDetectedInMultiplyByTen(), and Decimal::positive.

IntegerType getInteger

(

RoundingAlgorithmType

roundingAlgorithm = round

)

const throw (std::overflow_error)

Return this number as a C++ integer type.

Parameters:

roundingAlgorithm

Decimal::RoundingAlgorithmType

Returns:

integer result if the result will fit.

Exceptions:

std::overflow_error

if the result will not fit

References Decimal::bankersRound, Decimal::positive, and Decimal::round.

FloatingPointType getFloatingPoint

(

)

const

Return this number as a C++ floating point type.

Returns:

binary floating point result, which is computed with binary floating point arithmetic, and hence is an approximation.

References Decimal::positive.

int getInt

(

)

const throw (std::overflow_error)

Return this decimal number rounded as a C++ int.

Returns:

int result if the result will fit.

Exceptions:

std::overflow_error

if the result will not fit

int32_t getInt32

(

)

const throw (std::overflow_error)

Return this decimal number rounded as a C++ int32_t.

Returns:

int32_t result if the result will fit.

Exceptions:

std::overflow_error

if the result will not fit

unsigned getUnsigned

(

)

const throw (std::overflow_error)

Return this decimal number rounded as a C++ unsigned.

Returns:

unsigned result if the result will fit.

Exceptions:

std::overflow_error

if the result will not fit

uint32_t getUnsigned32

(

)

const throw (std::overflow_error)

Return this decimal number rounded as a C++ uint32_t.

Returns:

uint32_t result if the result will fit.

Exceptions:

std::overflow_error

if the result will not fit

int64_t getInt64

(

)

const throw (std::overflow_error)

Return this decimal number rounded as a C++ int64_t.

Returns:

int64_t result if the result will fit.

Exceptions:

std::overflow_error

if the result will not fit

uint64_t getUnsigned64

(

)

const throw (std::overflow_error)

Return this decimal number rounded as a C++ uint64_t.

Returns:

uint64_t number, if the result will fit.

Exceptions:

std::overflow_error

if the result will not fit

float getFloat

(

)

const

Convert to a C++ float.

Returns:

float result, which is computed with binary floating point arithmetic, and hence is an approximation.

double getDouble

(

)

const

Convert to a C++ double.

Returns:

double result, which is computed with binary floating point arithmetic, and hence is an approximation.

void setInteger

(

IntegerType

num

)

Set this this tntdb::Decimal object to the value of the given integer type.

Parameters:

num

integer value to set this Decimal number to.

References Decimal::infinity, Decimal::NaN, and Decimal::positive.

void setFloatingPoint

(

FloatingPointType

num

)

Set this this tntdb::Decimal object to the value of the given floating point type.

Parameters:

num

floating point value to set this Decimal number to.

References Decimal::read().

void setDecimalInteger	(	IntegerType	num,
		int32_t	exponent
	)

Set this this tntdb::Decimal object to the value of the given integer type mantissa and base 10 exponent.

Parameters:

	num	integer decimal mantissa value to set this Decimal number to.
	exponent	integer base 10 exponent to set this Decimal number to.

void setInt

(

int

num

)

Set this this tntdb::Decimal object to the value of the given int.

Parameters:

num

integer value to set this Decimal number to.

void setInt32

(

int32_t

num

)

Set this this tntdb::Decimal object to the value of the given int32_t.

Parameters:

num

integer value to set this Decimal number to.

void setUnsigned

(

unsigned

num

)

Set this this tntdb::Decimal object to the value of the given unsigned.

Parameters:

num

integer value to set this Decimal number to.

void setUnsigned32

(

uint32_t

num

)

Set this this tntdb::Decimal object to the value of the given uint32_t.

Parameters:

num

integer value to set this Decimal number to.

void setInt64

(

int64_t

num

)

Set this this tntdb::Decimal object to the value of the given int64_t.

Parameters:

num

integer value to set this Decimal number to.

void setUnsigned64

(

uint64_t

num

)

Set this this tntdb::Decimal object to the value of the given uint64_t.

Parameters:

num

integer value to set this Decimal number to.

void setDecimalInt64	(	int64_t	num,
		int32_t	exp
	)

Set this this tntdb::Decimal object to the value of the given int64_t decimal mantissa and base 10 exponent.

Parameters:

	num	decimal mantissa integer value to set this Decimal number to.
	exp	base 10 exponent.

void setDecimalUnsigned64	(	uint64_t	num,
		int32_t	exp
	)

Set this this tntdb::Decimal object to the value of the given uint64_t decimal mantissa and base 10 exponent.

Parameters:

	num	decimal mantissa integer value to set this Decimal number to.
	exp	base 10 exponent.

void setFloat

(

float

num

)

Set this this tntdb::Decimal object to the value of the given float.

Parameters:

num

float value to set this Decimal number to.

void setDouble

(

double

num

)

Set this this tntdb::Decimal object to the value of the given double.

Parameters:

num

double value to set this Decimal number to.

std::string toString

(

)

const

Return this Decimal number as a string.

Returns:

string representation of this decimal number.

std::ostream& print

(

std::ostream &

out

)

const

Print this Decimal number. If out.precision() != 0, then this decimal number is printed with out.precision() significant digits.

Parameters:

out

output stream

std::ostream& print	(	std::ostream &	out,
		PrintFlagsType	printFlags
	)			const

Print this Decimal number. If out.precision() != 0, then this decimal number is printed with out.precision() significant digits.

Parameters:

	out	output stream
	printFlags	the optional printFlags only affect how positive and negative infinity are printed.

std::istream& read	(	std::istream &	in,
		bool	ignoreOverflowReadingFraction = false
	)

Read a Decimal number.

Parameters:

	in	input stream
	ignoreOverflowReadingFraction	if true, ignore overflow errors while reading the fractional part, and set the mantissa to the the value before the overflow. This is useful while converting from float or double values to Decimal. The full range of significant digits that the Decimal can hold can be read in the conversion like: std::ostringstream ostr; ostr.precision(24); ostr << num; read(ostr.str(), true);

Referenced by Decimal::setFloatingPoint().

bool overflowDetectedInMultiplyByTen

(

T &

n

)

[static]

Multiply an integer type by 10, checking for overflow.

Parameters:

n

on input: the number to multply by 10, on output, the result of the multiplication by 10.

Returns:

true if overflow detected, else false.

Referenced by Decimal::divideByPowerOfTen(), Decimal::getIntegralFractionalExponent(), and Decimal::numberOfDigits().

void divideByPowerOfTen	(	const ManType	dividend,
		ManType &	quotient,
		ManType &	remainder,
		ManType	divisorPowerOfTenDigits
	)			throw (std::overflow_error) [static]

Divide an integer type by a power of 10 divisor, checking for overflow.

Parameters:

	dividend	the integer dividend.
	quotient	the result of the division by the power of 10 divisor.
	remainder	the remainder result of the division by the power of 10 divisor.
	divisorPowerOfTenDigits	divide by 10^divisorPowerOfTenDigits.

Returns:

true if overflow detected, else false.

Exceptions:

std::overflow_error

if the result will not fit

References Decimal::overflowDetectedInMultiplyByTen().

Referenced by Decimal::getIntegralFractionalExponent().

void init	(	MantissaType	m,
		ExponentType	e,
		FlagsType	f = positive,
		PrintFlagsType	pf = infinityShort
	)			[protected]

Initialize this Decimal number, called by the constructors.

Parameters:

	m	integer decimal mantissa value to set this Decimal number to.
	e	integer base 10 exponent to set this Decimal number to.
	f	the flags, need to specify positive or negative. Decimal::FlagsTypeEnum
	pf	the print flags for infinity and not a number. Decimal::InfinityOutputType