obint_private.h File Reference

obint Private Interface More...

#include "../obint.h"

Go to the source code of this file.

Classes
struct	obint_struct
	obint internal structure, encapsulating all data needed for an instance of obint More...

Functions
obint *	obint_create_default (uint64_t num_digits)
	Default constructor for obint. More...
ob_hash_t	obint_hash (const obj *to_hash)
	Hash function for obint. More...
int8_t	obint_compare (const obj *a, const obj *b)
	Compares two instances of obint. More...
int8_t	obint_compare_magnitudes (const obint *a, const obint *b)
	Compares magnitudes of two instances of obint. More...
void	obint_display (const obj *to_print)
	Descriptor for an instance of obint, prints relevant information about the class to stderr. More...
void	obint_destroy (obj *to_dealloc)
	Destructor for obint. More...
obint *	obint_add_unsigned (const obint *a, const obint *b)
	Creates a new integer as a result of addition between two obints with sign value ignored. More...
obint *	obint_subtract_unsigned (const obint *a, const obint *b)
	Creates a new integer as a result of subtraction between two obints with sign ignored. More...
obint *	obint_multiply_unsigned (const obint *a, const obint *b)
	Creates a new integer as a result of multiplication between two obints with sign ignored. More...
obint *	obint_reduce (const obint *a, const obint *b, const obint *approx, uint8_t quotient)
	Creates a new integer as a result of divison or modulus between two obints with sign ignored. More...
uint64_t	obint_most_sig (const obint *a)
	Returns the index where the most significant non-zero digit occurs, or zero if there are no non-zero digits. More...
void	obint_split (const obint *a, uint64_t i, obint **b1, obint **b0)
	Splits the obint into two obint instances at given index. More...
void	obint_shift (obint *a, uint64_t m)
	Shifts the obint the given number of digits to the left, in place, essentially unsigned multiplication by 10^m. More...
int64_t	obint_magnitude (const obint *a)
	Returns the unsigned value of the obint. More...
void	obint_set_max_digits (uint8_t digits)
	Sets the number of digits operated on in a primitive from 1 to 17. More...

Detailed Description

obint Private Interface

Author

theck

Function Documentation

obint* obint_add_unsigned	(	const obint *	a,
		const obint *	b
	)

Creates a new integer as a result of addition between two obints with sign value ignored.

Parameters

a	A non-NULL pointer to type obint
b	A non-NULL pointer to type obint

Returns

An instance of obint, which may or may not have proper sign

int8_t obint_compare	(	const obj *	a,
		const obj *	b
	)

Compares two instances of obint.

Parameters

a	A non-NULL obj pointer to type obint
b	A non-NULL obj pointer to type obint

Return values

OB_LESS_THAN	obj a is less than b
OB_GREATER_THAN	obj a is greater than b
OB_EQUAL_TO	obj a is equal to b

int8_t obint_compare_magnitudes	(	const obint *	a,
		const obint *	b
	)

Compares magnitudes of two instances of obint.

Parameters

a	A non-NULL pointer to type obint
b	A non-NULL pointer to type obint

Return values

OB_LESS_THAN	Magnitude of a a is less than b
OB_GREATER_THAN	Magnitude of a is greater than to b
OB_EQUAL_TO	Magnitude of a is equal to b

obint* obint_create_default

(

uint64_t

num_digits)

Default constructor for obint.

Parameters

num_digits

Approximate number of digits required to store the entire, always overestimate to ensure enough space is reserved

Returns

An instance of class obint

Warning

All public constructors should call this constructor and intialize individual members as needed, so that all base data is initialized properly.

void obint_destroy

(

obj *

to_dealloc)

Destructor for obint.

Parameters

to_dealloc

An obj pointer to an instance of obint with reference count of 0

Warning

Do not call manually, release will call automatically when the instances reference count drops to 0!

void obint_display

(

const obj *

to_print)

Descriptor for an instance of obint, prints relevant information about the class to stderr.

Parameters

to_print

A non-NULL obj pointer to an instance of type obint

ob_hash_t obint_hash

(

const obj *

to_hash)

Hash function for obint.

Parameters

to_hash

An obj pointer to an instance of obint

Returns

Key value (hash) for the given obj pointer to a obint

int64_t obint_magnitude

(

const obint *

a)

Returns the unsigned value of the obint.

Parameters

a	A non-NULL pointer to type obint

Returns

a positive int64_t representing the value of the argument obint

uint64_t obint_most_sig

(

const obint *

a)

Returns the index where the most significant non-zero digit occurs, or zero if there are no non-zero digits.

Parameters

a	A non-NULL pointer to type obint

Returns

An integer index where the most significant non-zero digit in a can be found

obint* obint_multiply_unsigned	(	const obint *	a,
		const obint *	b
	)

Creates a new integer as a result of multiplication between two obints with sign ignored.

Parameters

a	A non-NULL pointer to type obint
b	A non-NULL pointer to type obint

Returns

An instance of obint, which may or may not have proper sign

Multiplication performed using the Karatsuba multiplcation algorithm

obint* obint_reduce	(	const obint *	a,
		const obint *	b,
		const obint *	approx,
		uint8_t	quotient
	)

Creates a new integer as a result of divison or modulus between two obints with sign ignored.

Parameters

a	A non-NULL pointer to type obint
b	A non-NULL pointer to type obint
approx	A non-NULL pointer to type obint used to accumulate a quotient value
quotient	A boolean value, 0 indicates that a remainder should be returned, non-zero indicates a quotient should be returned

Returns

An instance of obint, which may or may not have proper sign

void obint_set_max_digits

(

uint8_t

digits)

Sets the number of digits operated on in a primitive from 1 to 17.

Parameters

digits

An integer between 2 and 17 inclusive

Warning

If digits does not fall in the 2 to 17 inclusive range nothing is done

The default value of 17 is most efficient, this method exists for testing purposes only!

void obint_shift	(	obint *	a,
		uint64_t	m
	)

Shifts the obint the given number of digits to the left, in place, essentially unsigned multiplication by 10^m.

int

Parameters

a	A non-NULL pointer to type obint
m	Number of digits to shift

void obint_split	(	const obint *	a,
		uint64_t	i,
		obint **	b1,
		obint **	b0
	)

Splits the obint into two obint instances at given index.

Parameters

a	A non-NULL pointer to type obint to be split
i	The integer index where the split occurs, where a-digits[i] is placed in the most significant section of the split
b1	A reference to a pointer to type obint, used to return the most significant section of the obint being split
b0	A reference to a pointer to type obint, used to return the least significant section of the obint being split

If index i extends beyond the bounds of a then b1 is set to point to a 0 obint and b2 is set to point to a copy of a. a is treated as unsigned for this operation

obint* obint_subtract_unsigned	(	const obint *	a,
		const obint *	b
	)

Creates a new integer as a result of subtraction between two obints with sign ignored.

Parameters

a	A non-NULL pointer to type obint, larger or equal to b
b	A non-NULL pointer to type obint, smaller or equal to a

Returns

An instance of obint, which may or may not have proper sign

Warning

Proper results guaranteed only for a >= b, a < b will not work and probably will cause segmentation faults