Struct sp_arithmetic::biguint::BigUint

pub struct BigUint { /* private fields */ }

Simple wrapper around an infinitely large integer, represented as limbs of Single.

Implementations

impl BigUint

pub fn with_capacity(size: usize) -> Self

Create a new instance with size limbs. This prevents any number with zero limbs to be created.

The behavior of the type is undefined with zero limbs.

pub fn from_limbs(limbs: &[Single]) -> Self

Raw constructor from custom limbs. If limbs is empty, Zero::zero() implementation is used.

pub fn len(&self) -> usize

Number of limbs.

pub fn get(&self, index: usize) -> Single

A naive getter for limb at index. Note that the order is lsb -> msb.

Panics

This panics if index is out of range.

pub fn checked_get(&self, index: usize) -> Option<Single>

A naive getter for limb at index. Note that the order is lsb -> msb.

pub fn set(&mut self, index: usize, value: Single)

A naive setter for limb at index. Note that the order is lsb -> msb.

Panics

This panics if index is out of range.

pub fn lsb(&self) -> Single

returns the least significant limb of the number.

Panics

While the constructor of the type prevents this, this can panic if self has no digits.

pub fn msb(&self) -> Single

returns the most significant limb of the number.

Panics

While the constructor of the type prevents this, this can panic if self has no digits.

pub fn lstrip(&mut self)

Strips zeros from the left side (the most significant limbs) of self, if any.

pub fn lpad(&mut self, size: usize)

Zero-pad self from left to reach size limbs. Will not make any difference if self is already bigger than size limbs.

pub fn add(self, other: &Self) -> Self

Adds self with other. self and other do not have to have any particular size. Given that the n = max{size(self), size(other)}, it will produce a number with n + 1 limbs.

This function does not strip the output and returns the original allocated n + 1 limbs. The caller may strip the output if desired.

Taken from “The Art of Computer Programming” by D.E. Knuth, vol 2, chapter 4.

pub fn sub(self, other: &Self) -> Result<Self, Self>

Subtracts other from self. self and other do not have to have any particular size. Given that the n = max{size(self), size(other)}, it will produce a number of size n.

If other is bigger than self, Err(B - borrow) is returned.

Taken from “The Art of Computer Programming” by D.E. Knuth, vol 2, chapter 4.

pub fn mul(self, other: &Self) -> Self

Multiplies n-limb number self with m-limb number other.

The resulting number will always have n + m limbs.

This function does not strip the output and returns the original allocated n + m limbs. The caller may strip the output if desired.

Taken from “The Art of Computer Programming” by D.E. Knuth, vol 2, chapter 4.

pub fn div_unit(self, other: Single) -> Self

Divides self by a single limb other. This can be used in cases where the original division cannot work due to the divisor (other) being just one limb.

Invariant: other cannot be zero.

pub fn div(self, other: &Self, rem: bool) -> Option<(Self, Self)>

Divides an n + m limb self by a n limb other. The result is a m + 1 limb quotient and a n limb remainder, if enabled by passing true in rem argument, both in the form of an option’s Ok.

• requires other to be stripped and have no leading zeros.
• requires self to be stripped and have no leading zeros.
• requires other to have at least two limbs.
• requires self to have a greater length compared to other.

All arguments are examined without being stripped for the above conditions. If any of the above fails, None is returned.`

Taken from “The Art of Computer Programming” by D.E. Knuth, vol 2, chapter 4.

Trait Implementations

impl Add<BigUint> for BigUint

type Output = Self

The resulting type after applying the + operator.

fn add(self, rhs: Self) -> Self::Output

Performs the + operation.

impl Clone for BigUint

fn clone(&self) -> BigUint

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for BigUint

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for BigUint

fn default() -> BigUint

Returns the “default value” for a type.

impl From<u128> for BigUint

fn from(a: u128) -> Self

Performs the conversion.

impl From<u16> for BigUint

fn from(a: u16) -> Self

Performs the conversion.

impl From<u32> for BigUint

fn from(a: u32) -> Self

Performs the conversion.

impl From<u64> for BigUint

fn from(a: Double) -> Self

Performs the conversion.

impl From<u8> for BigUint

fn from(a: u8) -> Self

Performs the conversion.

impl Mul<BigUint> for BigUint

type Output = Self

The resulting type after applying the * operator.

fn mul(self, rhs: Self) -> Self::Output

Performs the * operation.

impl One for BigUint

fn one() -> Self

Returns the multiplicative identity element of Self, 1.

fn set_one(&mut self)

Sets self to the multiplicative identity element of Self, 1.

fn is_one(&self) -> bool where
    Self: PartialEq<Self>, 

Returns true if self is equal to the multiplicative identity.

impl Ord for BigUint

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

impl PartialEq<BigUint> for BigUint

fn eq(&self, other: &Self) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialOrd<BigUint> for BigUint

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl Sub<BigUint> for BigUint

type Output = Self

The resulting type after applying the - operator.

fn sub(self, rhs: Self) -> Self::Output

Performs the - operation.

impl TryFrom<BigUint> for u128

type Error = &'static str

The type returned in the event of a conversion error.

fn try_from(value: BigUint) -> Result<u128, Self::Error>

Performs the conversion.

impl TryFrom<BigUint> for u64

type Error = &'static str

The type returned in the event of a conversion error.

fn try_from(value: BigUint) -> Result<u64, Self::Error>

Performs the conversion.

impl Zero for BigUint

fn zero() -> Self

Returns the additive identity element of Self, 0.

fn is_zero(&self) -> bool

Returns true if self is equal to the additive identity.

fn set_zero(&mut self)

Sets self to the additive identity element of Self, 0.

impl Eq for BigUint