Struct Env

pub struct Env<C: ArrabbiataCurve>
where
    C::BaseField: PrimeField,
{
    pub a: BigInt,
    pub idx_var: usize,
    pub idx_var_next_row: usize,
    pub constraints: Vec<E<C::ScalarField>>,
}

Fields

a: BigInt

The parameter a is the coefficients of the elliptic curve in affine coordinates.

idx_var: usize

idx_var_next_row: usize

constraints: Vec<E<C::ScalarField>>

Implementations

impl<C: ArrabbiataCurve> Env<C>

where C::BaseField: PrimeField,

pub fn new() -> Self

impl<C: ArrabbiataCurve> Env<C>

where C::BaseField: PrimeField,

pub fn get_all_constraints_for_verifier(&self) -> Vec<E<C::ScalarField>>

Get all the constraints for the verifier circuit, only.

The following gadgets are used in the verifier circuit:

• Instruction::PoseidonFullRound and Instruction::PoseidonSpongeAbsorb to verify the challenges and the public IO.
• Instruction::EllipticCurveScaling and Instruction::EllipticCurveAddition to accumulate the commitments

pub fn get_all_constraints(&self) -> Vec<E<C::ScalarField>>

Get all the constraints for the verifier circuit and the application.

pub fn get_all_constraints_indexed_by_gadget( &self, ) -> HashMap<Gadget, Vec<E<C::ScalarField>>>

Trait Implementations

impl<C: Clone + ArrabbiataCurve> Clone for Env<C>

where C::BaseField: PrimeField, C::ScalarField: Clone,

fn clone(&self) -> Env<C>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<C: Debug + ArrabbiataCurve> Debug for Env<C>

where C::BaseField: PrimeField, C::ScalarField: Debug,

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

Formats the value using the given formatter.

impl<C: ArrabbiataCurve> Default for Env<C>

where C::BaseField: PrimeField,

fn default() -> Self

Returns the “default value” for a type.

impl<C: ArrabbiataCurve> InterpreterEnv for Env<C>

where C::BaseField: PrimeField,

An environment to build constraints. The constraint environment is mostly useful when we want to perform a Nova proof. The constraint environment must be instantiated only once, at the last step of the computation.

fn write_column( &mut self, pos: Self::Position, v: Self::Variable, ) -> Self::Variable

Return the corresponding expression regarding the selected column

unsafe fn inverse( &mut self, pos: Self::Position, x: Self::Variable, ) -> Self::Variable

Inverse of a variable

Safety

Zero is not allowed as an input.

fn double_ec_point( &mut self, pos_x: Self::Position, pos_y: Self::Position, x1: Self::Variable, y1: Self::Variable, ) -> (Self::Variable, Self::Variable)

Double the elliptic curve point given by the affine coordinates (x1, y1) and save the result in the registers pos_x and pos_y.

type Position = (Column, CurrOrNext)

type Variable = Operations<ExprInner<Operations<ConstantExprInner<<C as AffineRepr>::ScalarField, ChallengeTerm>>, Column>>

The variable should be seen as a certain object that can be built by multiplying and adding, i.e. the variable can be seen as a solution to a polynomial. When instantiating as expressions - “constraints” - it defines multivariate polynomials.

fn allocate(&mut self) -> Self::Position

Allocate a new variable in the circuit for the current row

fn allocate_next_row(&mut self) -> Self::Position

Allocate a new variable in the circuit for the next row

fn read_position(&self, pos: Self::Position) -> Self::Variable

Return the corresponding variable at the given position

fn constant(&self, value: BigInt) -> Self::Variable

fn add_constraint(&mut self, constraint: Self::Variable)

fn constrain_boolean(&mut self, x: Self::Variable)

fn assert_zero(&mut self, x: Self::Variable)

Assert that the variable is zero

fn assert_equal(&mut self, x: Self::Variable, y: Self::Variable)

Assert that the two variables are equal

unsafe fn bitmask_be( &mut self, _x: &Self::Variable, _highest_bit: u32, _lowest_bit: u32, pos: Self::Position, ) -> Self::Variable

Flagged as unsafe as it does require an additional range check

fn square(&mut self, pos: Self::Position, x: Self::Variable) -> Self::Variable

Compute the square a field element

fn fetch_input(&mut self, pos: Self::Position) -> Self::Variable

Fetch an input of the application

fn reset(&mut self)

Reset the environment to build the next row

fn coin_folding_combiner(&mut self, pos: Self::Position) -> Self::Variable

Return the folding combiner

fn load_poseidon_state( &mut self, pos: Self::Position, _i: usize, ) -> Self::Variable

Load the state of the Poseidon hash function into the environment

unsafe fn save_poseidon_state(&mut self, _x: Self::Variable, _i: usize)

Save the state of poseidon into the environment

fn get_poseidon_round_constant(&self, round: usize, i: usize) -> Self::Variable

Return the Poseidon round constants as a constant.

fn get_poseidon_mds_matrix(&mut self, i: usize, j: usize) -> Self::Variable

Return the requested MDS matrix coefficient

unsafe fn fetch_value_to_absorb( &mut self, pos: Self::Position, ) -> Self::Variable

Load the value to absorb at the current step at the position given by pos.

unsafe fn load_temporary_accumulators( &mut self, pos_x: Self::Position, pos_y: Self::Position, _side: Side, ) -> (Self::Variable, Self::Variable)

Load the affine coordinates of the elliptic curve point currently saved in the temporary accumulators. Temporary accumulators could be seen as a CPU cache, an intermediate storage between the RAM (random access memory) and the CPU registers (memory cells that are constrained).

unsafe fn save_temporary_accumulators( &mut self, _x: Self::Variable, _y: Self::Variable, _side: Side, )

Save temporary accumulators into the environment

unsafe fn is_same_ec_point( &mut self, pos: Self::Position, _x1: Self::Variable, _y1: Self::Variable, _x2: Self::Variable, _y2: Self::Variable, ) -> Self::Variable

Check if the points given by (x1, y1) and (x2, y2) are equals.

fn zero(&self) -> Self::Variable

Build the constant zero

fn one(&self) -> Self::Variable

Build the constant one

fn compute_lambda( &mut self, pos: Self::Position, is_same_point: Self::Variable, x1: Self::Variable, y1: Self::Variable, x2: Self::Variable, y2: Self::Variable, ) -> Self::Variable

Compute the coefficient λ used in the elliptic curve addition. If the two points are the same, the λ is computed as follows:

fn compute_x5(&self, x: Self::Variable) -> Self::Variable

Compute the x^5 of the given variable