Enum SymbolicExpr

pub enum SymbolicExpr {
    Input(usize),
    Var(usize),
    Const(usize, BigUint, usize),
    Add(Box<SymbolicExpr>, Box<SymbolicExpr>),
    Sub(Box<SymbolicExpr>, Box<SymbolicExpr>),
    Mul(Box<SymbolicExpr>, Box<SymbolicExpr>),
    Div(Box<SymbolicExpr>, Box<SymbolicExpr>),
    IntAdd(Box<SymbolicExpr>, isize),
    IntMul(Box<SymbolicExpr>, isize),
    Select(usize, Box<SymbolicExpr>, Box<SymbolicExpr>),
}

Example: If there are 4 inputs (x1, y1, x2, y2), and one intermediate variable lambda, Mul(Var(0), Var(0)) - Input(0) - Input(2) => lambda * lambda - x1 - x2

Variants

Input(usize)

Var(usize)

Const(usize, BigUint, usize)

Add(Box<SymbolicExpr>, Box<SymbolicExpr>)

Sub(Box<SymbolicExpr>, Box<SymbolicExpr>)

Mul(Box<SymbolicExpr>, Box<SymbolicExpr>)

Div(Box<SymbolicExpr>, Box<SymbolicExpr>)

IntAdd(Box<SymbolicExpr>, isize)

IntMul(Box<SymbolicExpr>, isize)

Select(usize, Box<SymbolicExpr>, Box<SymbolicExpr>)

Implementations

impl SymbolicExpr

pub fn constraint_limb_max_abs( &self, limb_bits: usize, num_limbs: usize, ) -> usize

Returns the maximum possible size, in bits, of each limb in self.expr. This is already tracked in FieldVariable. However when auto saving in FieldVariable::div, we need to know it from the SymbolicExpr only. self should be a constraint expr.

pub fn constraint_carry_bits_with_pq( &self, prime: &BigUint, limb_bits: usize, num_limbs: usize, proper_max: &BigUint, ) -> usize

Returns the maximum possible size, in bits, of each carry in self.expr - q * p. self should be a constraint expr.

The cached value proper_max should equal 2^{limb_bits * num_limbs} - 1.

pub fn expr_limbs(&self, num_limbs: usize) -> usize

Returns the number of limbs needed to represent the expression. The parameter num_limbs is the number of limbs of a canonical field element.

pub fn constraint_limbs( &self, prime: &BigUint, limb_bits: usize, num_limbs: usize, proper_max: &BigUint, ) -> (usize, usize)

Let q be such that self.expr = q * p. Returns (q_limbs, carry_limbs) where q_limbs is the number of limbs in q and carry_limbs is the number of limbs in the carry of the constraint self.expr - q * p = 0. self should be a constraint expression.

The cached value proper_max should equal 2^{limb_bits * num_limbs} - 1.

pub fn evaluate_bigint( &self, inputs: &[BigInt], variables: &[BigInt], flags: &[bool], ) -> BigInt

Used in trace gen to compute `q``. self should be a constraint expression.

pub fn evaluate_overflow_isize( &self, inputs: &[OverflowInt<isize>], variables: &[OverflowInt<isize>], constants: &[OverflowInt<isize>], flags: &[bool], ) -> OverflowInt<isize>

Used in trace gen to compute carries. self should be a constraint expression.

pub fn evaluate_overflow_expr<AB: AirBuilder>( &self, inputs: &[OverflowInt<AB::Expr>], variables: &[OverflowInt<AB::Expr>], constants: &[OverflowInt<AB::Expr>], flags: &[AB::Var], ) -> OverflowInt<AB::Expr>

Used in AIR eval. self should be a constraint expression.

pub fn compute( &self, inputs: &[BigUint], variables: &[BigUint], flags: &[bool], prime: &BigUint, ) -> BigUint

Result will be within [0, prime). self should be a compute expression. Note that division by zero will panic.

Trait Implementations

impl Add<&SymbolicExpr> for SymbolicExpr

type Output = SymbolicExpr

The resulting type after applying the + operator.

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

Performs the + operation.

impl Add<SymbolicExpr> for &SymbolicExpr

type Output = SymbolicExpr

The resulting type after applying the + operator.

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

Performs the + operation.

impl Add for &SymbolicExpr

type Output = SymbolicExpr

The resulting type after applying the + operator.

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

Performs the + operation.

impl Add for SymbolicExpr

type Output = SymbolicExpr

The resulting type after applying the + operator.

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

Performs the + operation.

impl Clone for SymbolicExpr

fn clone(&self) -> SymbolicExpr

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for SymbolicExpr

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

Formats the value using the given formatter.

impl Display for SymbolicExpr

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

Formats the value using the given formatter.

impl Div<&SymbolicExpr> for SymbolicExpr

type Output = SymbolicExpr

The resulting type after applying the / operator.

fn div(self, rhs: &SymbolicExpr) -> Self::Output

Performs the / operation.

impl Div<SymbolicExpr> for &SymbolicExpr

type Output = SymbolicExpr

The resulting type after applying the / operator.

fn div(self, rhs: SymbolicExpr) -> Self::Output

Performs the / operation.

impl Div for &SymbolicExpr

type Output = SymbolicExpr

The resulting type after applying the / operator.

fn div(self, rhs: &SymbolicExpr) -> Self::Output

Performs the / operation.

impl Div for SymbolicExpr

type Output = SymbolicExpr

The resulting type after applying the / operator.

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

Performs the / operation.

impl Mul<&SymbolicExpr> for SymbolicExpr

type Output = SymbolicExpr

The resulting type after applying the * operator.

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

Performs the * operation.

impl Mul<SymbolicExpr> for &SymbolicExpr

type Output = SymbolicExpr

The resulting type after applying the * operator.

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

Performs the * operation.

impl Mul for &SymbolicExpr

type Output = SymbolicExpr

The resulting type after applying the * operator.

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

Performs the * operation.

impl Mul for SymbolicExpr

type Output = SymbolicExpr

The resulting type after applying the * operator.

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

Performs the * operation.

impl PartialEq for SymbolicExpr

fn eq(&self, other: &SymbolicExpr) -> 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 Sub<&SymbolicExpr> for SymbolicExpr

type Output = SymbolicExpr

The resulting type after applying the - operator.

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

Performs the - operation.

impl Sub<SymbolicExpr> for &SymbolicExpr

type Output = SymbolicExpr

The resulting type after applying the - operator.

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

Performs the - operation.

impl Sub for &SymbolicExpr

type Output = SymbolicExpr

The resulting type after applying the - operator.

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

Performs the - operation.

impl Sub for SymbolicExpr

type Output = SymbolicExpr

The resulting type after applying the - operator.

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

Performs the - operation.

impl StructuralPartialEq for SymbolicExpr