1//! This module implements the R1CS equivalent of `ark_bandersnatch`.
  2//!
  3//! It implements field variables for `crate::Fq`,
  4//! and group variables for `crate::Projective`.
  5//!
  6//! The field underlying these constraints is `crate::Fq`.
  7//!
  8//! # Examples
  9//!
 10//! One can perform standard algebraic operations on `FqVar`:
 11//!
 12//! ```
 13//! # fn main() -> Result<(), ark_relations::r1cs::SynthesisError> {
 14//! use ark_std::UniformRand;
 15//! use ark_relations::r1cs::*;
 16//! use ark_r1cs_std::prelude::*;
 17//! use ark_ed_on_bls12_381_bandersnatch::{*, constraints::*};
 18//!
 19//! let cs = ConstraintSystem::<Fq>::new_ref();
 20//! // This rng is just for test purposes; do not use it
 21//! // in real applications.
 22//! let mut rng = ark_std::test_rng();
 23//!
 24//! // Generate some random `Fq` elements.
 25//! let a_native = Fq::rand(&mut rng);
 26//! let b_native = Fq::rand(&mut rng);
 27//!
 28//! // Allocate `a_native` and `b_native` as witness variables in `cs`.
 29//! let a = FqVar::new_witness(ark_relations::ns!(cs, "generate_a"), || Ok(a_native))?;
 30//! let b = FqVar::new_witness(ark_relations::ns!(cs, "generate_b"), || Ok(b_native))?;
 31//!
 32//! // Allocate `a_native` and `b_native` as constants in `cs`. This does not add any
 33//! // constraints or variables.
 34//! let a_const = FqVar::new_constant(ark_relations::ns!(cs, "a_as_constant"), a_native)?;
 35//! let b_const = FqVar::new_constant(ark_relations::ns!(cs, "b_as_constant"), b_native)?;
 36//!
 37//! let one = FqVar::one();
 38//! let zero = FqVar::zero();
 39//!
 40//! // Sanity check one + one = two
 41//! let two = &one + &one + &zero;
 42//! two.enforce_equal(&one.double()?)?;
 43//!
 44//! assert!(cs.is_satisfied()?);
 45//!
 46//! // Check that the value of &a + &b is correct.
 47//! assert_eq!((&a + &b).value()?, a_native + &b_native);
 48//!
 49//! // Check that the value of &a * &b is correct.
 50//! assert_eq!((&a * &b).value()?, a_native * &b_native);
 51//!
 52//! // Check that operations on variables and constants are equivalent.
 53//! (&a + &b).enforce_equal(&(&a_const + &b_const))?;
 54//! assert!(cs.is_satisfied()?);
 55//! # Ok(())
 56//! # }
 57//! ```
 58//!
 59//! One can also perform standard algebraic operations on `EdwardsVar`:
 60//!
 61//! ```
 62//! # fn main() -> Result<(), ark_relations::r1cs::SynthesisError> {
 63//! # use ark_std::UniformRand;
 64//! # use ark_relations::r1cs::*;
 65//! # use ark_r1cs_std::prelude::*;
 66//! # use ark_ed_on_bls12_381_bandersnatch::{*, constraints::*};
 67//!
 68//! # let cs = ConstraintSystem::<Fq>::new_ref();
 69//! # let mut rng = ark_std::test_rng();
 70//!
 71//! // Generate some random `Edwards` elements.
 72//! let a_native = EdwardsProjective::rand(&mut rng);
 73//! let b_native = EdwardsProjective::rand(&mut rng);
 74//!
 75//! // Allocate `a_native` and `b_native` as witness variables in `cs`.
 76//! let a = EdwardsVar::new_witness(ark_relations::ns!(cs, "a"), || Ok(a_native))?;
 77//! let b = EdwardsVar::new_witness(ark_relations::ns!(cs, "b"), || Ok(b_native))?;
 78//!
 79//! // Allocate `a_native` and `b_native` as constants in `cs`. This does not add any
 80//! // constraints or variables.
 81//! let a_const = EdwardsVar::new_constant(ark_relations::ns!(cs, "a_as_constant"), a_native)?;
 82//! let b_const = EdwardsVar::new_constant(ark_relations::ns!(cs, "b_as_constant"), b_native)?;
 83//!
 84//! // This returns the identity of `Edwards`.
 85//! let zero = EdwardsVar::zero();
 86//!
 87//! // Sanity check one + one = two
 88//! let two_a = &a + &a + &zero;
 89//! two_a.enforce_equal(&a.double()?)?;
 90//!
 91//! assert!(cs.is_satisfied()?);
 92//!
 93//! // Check that the value of &a + &b is correct.
 94//! assert_eq!((&a + &b).value()?, a_native + &b_native);
 95//!
 96//! // Check that operations on variables and constants are equivalent.
 97//! (&a + &b).enforce_equal(&(&a_const + &b_const))?;
 98//! assert!(cs.is_satisfied()?);
 99//! # Ok(())
100//! # }
101//! ```
102
103mod curves;
104mod fields;
105
106pub use curves::*;
107pub use fields::*;