Fixed-point decimal number. More...

#include <Decimal.h>

Inheritance diagram for utl::Decimal:

Public Member Functions
	Decimal (int64_t n)
	Constructor. More...

	Decimal (const String &str)
	Constructor. More...

virtual void	copy (const Object &rhs)
	Copy another instance. More...

virtual int	compare (const Object &rhs) const
	Compare with another object. More...

virtual void	serialize (Stream &stream, uint_t io, uint_t mode=ser_default)
	Serialize to or from a stream. More...

virtual String	toString () const
	Return a string representation of self. More...

String	toString (uint_t digits, bool round=true) const
	Convert to string representation. More...

Decimal &	set (const String &str)
	Set from string representation. More...

Decimal &	abs ()
	Take the absolute value. More...

Decimal &	floor ()
	Remove any fractional component. More...

Math Operators
Decimal	operator+ (const Decimal &rhs) const

Decimal &	operator+= (const Decimal &rhs)

Decimal	operator- (const Decimal &rhs) const

Decimal &	operator-= (const Decimal &rhs)

Decimal	operator* (const Decimal &rhs) const

Decimal &	*operator=** (const Decimal &rhs)

Decimal	operator/ (const Decimal &rhs) const

Decimal &	operator/= (const Decimal &rhs)

Decimal	operator% (const Decimal &rhs) const

Decimal &	operator++ ()

Decimal	operator++ (int)

Decimal &	operator-- ()

Decimal	operator-- (int)

Public Member Functions inherited from utl::Object
void	clear ()
	Revert to initial state. More...

virtual void	vclone (const Object &rhs)
	Make an exact copy of another instance. More...

virtual void	steal (Object &rhs)
	"Steal" the internal representation from another instance. More...

virtual void	dump (Stream &os, uint_t level=uint_t_max) const
	Dump a human-readable representation of self to the given output stream. More...

void	dumpWithClassName (Stream &os, uint_t indent=4, uint_t level=uint_t_max) const
	Front-end for dump() that prints the object's class name. More...

virtual const Object &	getKey () const
	Get the key for this object. More...

bool	hasKey () const
	Determine whether or not the object has a key. More...

virtual const Object &	getProxiedObject () const
	Get the proxied object (= self if none). More...

virtual Object &	getProxiedObject ()
	Get the proxied object (= self if none). More...

virtual size_t	hash (size_t size) const
	Get the hash code for the object. More...

bool	_isA (const RunTimeClass *runTimeClass) const
	Determine whether self's class is a descendent of the given class. More...

	operator String () const
	Conversion to String. More...

size_t	allocatedSize () const
	Get the total allocated size of this object. More...

virtual size_t	innerAllocatedSize () const
	Get the "inner" allocated size. More...

virtual void	addOwnedIt (const class FwdIt *it) const
	Notify self that it owns the given iterator. More...

virtual void	removeOwnedIt (const class FwdIt *it) const
	Notify self that the given owned iterator has been destroyed. More...

bool	operator< (const Object &rhs) const
	Less-than operator. More...

bool	operator<= (const Object &rhs) const
	Less-than-or-equal-to operator. More...

bool	operator> (const Object &rhs) const
	Greater-than operator. More...

bool	operator>= (const Object &rhs) const
	Greater-than-or-equal-to operator. More...

bool	operator== (const Object &rhs) const
	Equal-to operator. More...

bool	operator!= (const Object &rhs) const
	Unequal-to operator. More...

void	serializeIn (Stream &is, uint_t mode=ser_default)
	Serialize from an input stream. More...

void	serializeOut (Stream &os, uint_t mode=ser_default) const
	Serialize to an output stream. More...

void	serializeOutBoxed (Stream &os, uint_t mode=ser_default) const
	Serialize a boxed object to an output stream. More...

Additional Inherited Members
Static Public Member Functions inherited from utl::Object
static Object *	serializeInNullable (Stream &is, uint_t mode=ser_default)
	Serialize a nullptr-able object from an input stream. More...

static void	serializeOutNullable (const Object *object, Stream &os, uint_t mode=ser_default)
	Serialize a nullptr-able object to an output stream. More...

static void	serializeNullable (Object *&object, Stream &stream, uint_t io, uint_t mode=ser_default)
	Serialize a nullptr-able object to or from a stream. More...

static Object *	serializeInBoxed (Stream &is, uint_t mode=ser_default)
	Serialize a boxed object from an input stream. More...

static void	serializeBoxed (Object *&object, Stream &stream, uint_t io, uint_t mode=ser_default)
	Serialize a boxed object to or from a stream. More...

Detailed Description

Fixed-point decimal number.

This simple implementation uses a signed 64-bit integer as the raw encoding, and provides 6 decimal digits of precision. That is, the fractional part of the decimal number may be precisely expressed as a whole number of one-millionths.

Noting that:

the decimal number is stored in a signed 64-bit integer
6 decimal digits of precision are provided
size of the space of 64-bit values: 18,446,744,073,709,551,616.
half the above size is: 9,223,372,036,854,775,808.

We get:

minimum representable value: -9,223,372,036,854.775808
maximum representable value: +9,223,372,036,854.775807

Addition and subtraction are simple: just add or subtract the "raw" underlying integers, and the result of that is the correct decimal answer.

Multiplication and division are very simple too, but they do need a simple shift adjustment to restore correct scaling factor, as well as a rounding adjustment to minimize loss of precision when extra digits in the result of a calculation are discarded. For example, 2/3 will be calculated as 0.666667 (and not 0.666666).

Note that if you call toString() with digits < 6, the printed number may be rounded up to show the closest approximation to the actual stored number in the specified number of digits:

Decimal a("0.999999"), b("0.66899");
cout << a.toString(2) << endl;           // outputs "1.00" !
cout << b.toString(2) << endl;           // outputs "0.67"

If you don't want this behavior, specify round=false when calling toString().

Author: Adam McKee

Definition at line 57 of file Decimal.h.

Constructor & Destructor Documentation

◆ Decimal() [1/2]

utl::Decimal::Decimal ( int64_t n )

inline

Constructor.

Parameters

n	initial value

Definition at line 66 of file Decimal.h.

◆ Decimal() [2/2]

utl::Decimal::Decimal ( const String & str )

inline

Constructor.

Parameters

str	string representation of initial value

Definition at line 75 of file Decimal.h.

References utl::compare(), utl::copy(), utl::ser_default, utl::serialize(), and utl::toString().

Member Function Documentation

◆ copy()

virtual void utl::Decimal::copy ( const Object & rhs )

virtual

Copy another instance.

When you override copy(), you should usually call the superclass's copy().

Parameters

rhs	object to copy

Reimplemented from utl::Object.

◆ compare()

virtual int utl::Decimal::compare ( const Object & rhs ) const

virtual

Compare with another object.

If no overridden version succeeds in doing the comparison, then an attempt will be made to re-start the comparison process using one or both of the objects' keys. Usually, an override of compare() should call the superclass's compare() if it doesn't know how to compare itself with the rhs object.

See also: getKey

Returns: < 0 if self < rhs, 0 if self = rhs, > 0 if self > rhs

Parameters

rhs	object to compare with

Reimplemented from utl::Object.

◆ serialize()

virtual void utl::Decimal::serialize	(	Stream &	stream,
		uint_t	io,
		uint_t	mode = `ser_default`
	)

virtual

Serialize to or from a stream.

This is the only virtual method for serialization. You must override this in any class that has data to be serialized, and ensure that the superclass's serialize() gets called.

Parameters

stream	stream to serialize from/to
io	see utl::io_t
mode	see utl::serialize_t

Reimplemented from utl::Object.

◆ toString() [1/2]

virtual String utl::Decimal::toString ( ) const

virtual

Return a string representation of self.

Reimplemented from utl::Object.

◆ toString() [2/2]

String utl::Decimal::toString	(	uint_t	digits,
		bool	round = `true`
	)		const

Convert to string representation.

Parameters

digits	number of digits of precision
round	(optional : true) round up to show best approximation (if digits < 6)?

◆ set()

Decimal& utl::Decimal::set ( const String & str )

Set from string representation.

◆ abs()

Decimal& utl::Decimal::abs ( )

inline

Take the absolute value.

Definition at line 100 of file Decimal.h.

◆ floor()

Decimal& utl::Decimal::floor ( )

inline

Remove any fractional component.

Definition at line 108 of file Decimal.h.

References utl::deInit(), and utl::init().

The documentation for this class was generated from the following file:

Decimal.h

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ Decimal() [1/2]

◆ Decimal() [2/2]

Member Function Documentation

◆ copy()

◆ compare()

◆ serialize()

◆ toString() [1/2]

◆ toString() [2/2]

◆ set()

◆ abs()

◆ floor()