Module utils

Utility functions for converting between different types of field elements.

Modules

fs

Module for reading parameters for Halo2 proving system from the file system.

halo2

Helper functions for raw halo2 operations to unify slight differences in API for halo2-axiom and halo2-pse

Traits

BigPrimeField

Helper trait to convert to and from a BigPrimeField by converting a list of u64 digits

CurveAffineExt

ScalarField

Helper trait to represent a field element that can be converted into u64 limbs.

Functions

bigint_to_fe

Converts an immutable reference to BigInt to a BigPrimeField.

biguint_to_fe

Converts an immutable reference to BigUint to a BigPrimeField.

bit_length

Returns the number of bits needed to represent the value of x.

compose

Computes the value of an integer by passing as input a Vec of its limb values and the bit_len (bit length) used.

decompose

Decomposes an immutable reference to a BigPrimeField element into number_of_limbs limbs of bit_len bits each and returns a Vec of BigPrimeField represented by those limbs.

decompose_bigint

Decomposes an immutable reference to a BigInt into num_limbs limbs of bit_len bits each and returns a Vec of BigPrimeField represented by those limbs.

decompose_bigint_option

Decomposes an immutable reference to a BigInt into num_limbs limbs of bit_len bits each and returns a Vec of BigPrimeField represented by those limbs wrapped in Value.

decompose_biguint

Decomposes an immutable reference to a BigUint into num_limbs limbs of bit_len bits each and returns a Vec of BigPrimeField represented by those limbs.

decompose_fe_to_u64_limbs

Decomposes an immutable reference to a ScalarField element into number_of_limbs limbs of bit_len bits each and returns a Vec of u64 represented by those limbs.

fe_to_bigint

Converts a BigPrimeField element into a BigInt element by sending fe in [0, F::modulus()) to

fe_to_biguint

Converts an immutable reference to an PrimeField element into a BigUint element.

log2_ceil

Returns the ceiling of the base 2 logarithm of x.

modulus

Returns the modulus of BigPrimeField.

power_of_two

Returns the BigPrimeField element of 2ⁿ.

value_to_option

Wraps the internal value of value in an Option. If the value is None, then the function returns None.