Struct Poly 

pub struct Poly<K> { /* private fields */ }

A polynomial, with coefficients in K.

Implementations

impl<K> Poly<K>

pub fn degree(&self) -> u32

The degree of this polynomial.

Technically, this is only an upper bound on the degree, because this method does not inspect the coefficients of a polynomial to check if they’re non-zero.

Because of this, it’s possible that two polynomials considered equal have different degrees.

For that behavior, see Self::degree_exact.

pub fn required(&self) -> NonZeroU32

Return the number of evaluation points required to recover this polynomial.

In other words, Self::degree + 1.

pub fn constant(&self) -> &K

Return the constant value of this polynomial.

I.e. the first coefficient.

pub fn translate<L>(&self, f: impl Fn(&K) -> L) -> Poly<L>

Translate the coefficients of this polynomial.

This applies some kind of map to each coefficient, creating a new polynomial.

pub fn eval<R>(&self, r: &R) -> K

where K: Space<R>,

Evaluate a polynomial at a particular point.

For

p(X) := a_0 + a_1 X + a_2 X^2 + ...

this returns:

a_0 + a_1 r + a_2 r^2 + ...

This can work for any type which can multiply the coefficients of this polynomial.

For example, if you have a polynomial consistent of elements of a group, you can evaluate it using a scalar over that group.

pub fn eval_msm<R: Ring>(&self, r: &R) -> K

where K: Space<R>,

Like Self::eval, but using Space::msm.

This method uses more scratch space, and requires cloning values of type R more, but should be better if Space::msm has a better algorithm for K.

impl<K: Random> Poly<K>

pub fn new(rng: impl CryptoRngCore, degree: u32) -> Self

pub fn new_with_constant( rng: impl CryptoRngCore, degree: u32, constant: K, ) -> Self

Returns a new scalar polynomial with a particular value for the constant coefficient.

This does the same thing as Poly::new otherwise.

impl<K: Additive> Poly<K>

pub fn degree_exact(&self) -> u32

Like Self::degree, but checking for zero coefficients.

This method is slower, but reports exact results in case there are zeros.

This will return 0 for a polynomial with no coefficients.

impl<G: CryptoGroup> Poly<G>

pub fn commit(p: Poly<G::Scalar>) -> Self

Commit to a polynomial of scalars, producing a polynomial of group elements.

Trait Implementations

impl<'a, K: Additive> Add<&'a Poly<K>> for Poly<K>

type Output = Poly<K>

The resulting type after applying the + operator.

fn add(self, rhs: &'a Poly<K>) -> Self::Output

Performs the + operation.

impl<'a, K: Additive> AddAssign<&'a Poly<K>> for Poly<K>

fn add_assign(&mut self, rhs: &'a Poly<K>)

Performs the += operation.

impl<K: Additive> Additive for Poly<K>

fn zero() -> Self

The neutral element for addition.

fn double(&mut self)

Add an element to itself.

fn scale(&self, bits_le: &[u64]) -> Self

Scale this number by a positive integer.

impl<K: Clone> Clone for Poly<K>

fn clone(&self) -> Poly<K>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<K: Debug> Debug for Poly<K>

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

Formats the value using the given formatter.

impl<K: EncodeSize> EncodeSize for Poly<K>

fn encode_size(&self) -> usize

Returns the encoded size of this value (in bytes).

impl<'a, R, K: Space<R>> Mul<&'a R> for Poly<K>

type Output = Poly<K>

The resulting type after applying the * operator.

fn mul(self, rhs: &'a R) -> Self::Output

Performs the * operation.

impl<'a, R, K: Space<R>> MulAssign<&'a R> for Poly<K>

fn mul_assign(&mut self, rhs: &'a R)

Performs the *= operation.

impl<K: Additive> Neg for Poly<K>

type Output = Poly<K>

The resulting type after applying the - operator.

fn neg(self) -> Self::Output

Performs the unary - operation.

impl<K: Additive> PartialEq for Poly<K>

An equality test taking into account high 0 coefficients.

Without this behavior, the additive test suite does not past, because x - x may result in a polynomial with extra 0 coefficients.

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<K: Read> Read for Poly<K>

type Cfg = (RangeCfg<NonZero<u32>>, <K as Read>::Cfg)

The Cfg type parameter allows passing configuration during the read process. This is crucial for safely decoding untrusted data, for example, by providing size limits for collections or strings.

fn read_cfg(buf: &mut impl Buf, cfg: &Self::Cfg) -> Result<Self, Error>

Reads a value from the buffer using the provided configuration cfg.

impl<R: Sync, K: Space<R>> Space<R> for Poly<K>

Available on crate feature std only.

fn msm(polys: &[Self], scalars: &[R], concurrency: usize) -> Self

Calculate sum_i points[i] * scalars[i].

impl<'a, K: Additive> Sub<&'a Poly<K>> for Poly<K>

type Output = Poly<K>

The resulting type after applying the - operator.

fn sub(self, rhs: &'a Poly<K>) -> Self::Output

Performs the - operation.

impl<'a, K: Additive> SubAssign<&'a Poly<K>> for Poly<K>

fn sub_assign(&mut self, rhs: &'a Poly<K>)

Performs the -= operation.

impl<K: Write> Write for Poly<K>

fn write(&self, buf: &mut impl BufMut)

Writes the binary representation of self to the provided buffer buf.

impl<K: Additive> Eq for Poly<K>

impl<K: Additive> Object for Poly<K>