Module halo2_base::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
• testing
  Utilities for testing

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.