Enum halo2_middleware::expression::Expression

pub enum Expression<F, V: Variable> {
    Constant(F),
    Var(V),
    Negated(Box<Expression<F, V>>),
    Sum(Box<Expression<F, V>>, Box<Expression<F, V>>),
    Product(Box<Expression<F, V>>, Box<Expression<F, V>>),
}

Low-degree expression representing an identity that must hold over the committed columns.

Variants

Constant(F)

This is a constant polynomial

Var(V)

This is a variable

Negated(Box<Expression<F, V>>)

This is a negated polynomial

Sum(Box<Expression<F, V>>, Box<Expression<F, V>>)

This is the sum of two polynomials

Product(Box<Expression<F, V>>, Box<Expression<F, V>>)

This is the product of two polynomials

Implementations

impl<F: Field, V: Variable> Expression<F, V>

pub fn evaluate<T>( &self, constant: &impl Fn(F) -> T, var: &impl Fn(V) -> T, negated: &impl Fn(T) -> T, sum: &impl Fn(T, T) -> T, product: &impl Fn(T, T) -> T ) -> T

Evaluate the polynomial using the provided closures to perform the operations.

pub fn identifier(&self) -> String

Identifier for this expression. Expressions with identical identifiers do the same calculation (but the expressions don’t need to be exactly equal in how they are composed e.g. 1 + 2 and 2 + 1 can have the same identifier).

pub fn degree(&self) -> usize

Compute the degree of this polynomial

pub fn complexity(&self) -> usize

Approximate the computational complexity of this expression.

Trait Implementations

impl<F: Field, V: Variable> Add for Expression<F, V>

type Output = Expression<F, V>

The resulting type after applying the + operator.

fn add(self, rhs: Expression<F, V>) -> Expression<F, V>

Performs the + operation.

impl<F: Clone, V: Clone + Variable> Clone for Expression<F, V>

fn clone(&self) -> Expression<F, V>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<F: Debug, V: Debug + Variable> Debug for Expression<F, V>

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

Formats the value using the given formatter.

impl<F: Field, V: Variable> Mul<F> for Expression<F, V>

type Output = Expression<F, V>

The resulting type after applying the * operator.

fn mul(self, rhs: F) -> Expression<F, V>

Performs the * operation.

impl<F: Field, V: Variable> Mul for Expression<F, V>

type Output = Expression<F, V>

The resulting type after applying the * operator.

fn mul(self, rhs: Expression<F, V>) -> Expression<F, V>

Performs the * operation.

impl<F: Field, V: Variable> Neg for Expression<F, V>

type Output = Expression<F, V>

The resulting type after applying the - operator.

fn neg(self) -> Self::Output

Performs the unary - operation.

impl<F: PartialEq, V: PartialEq + Variable> PartialEq for Expression<F, V>

fn eq(&self, other: &Expression<F, V>) -> 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 !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<F: Field, V: Variable> Product for Expression<F, V>

fn product<I: Iterator<Item = Self>>(iter: I) -> Self

Method which takes an iterator and generates Self from the elements by multiplying the items.

impl<F: Field, V: Variable> Sub for Expression<F, V>

type Output = Expression<F, V>

The resulting type after applying the - operator.

fn sub(self, rhs: Expression<F, V>) -> Expression<F, V>

Performs the - operation.

impl<F: Field, V: Variable> Sum for Expression<F, V>

fn sum<I: Iterator<Item = Self>>(iter: I) -> Self

Method which takes an iterator and generates Self from the elements by “summing up” the items.

impl<F: Eq, V: Eq + Variable> Eq for Expression<F, V>

impl<F, V: Variable> StructuralPartialEq for Expression<F, V>