Require Neg, Sub, SubAssign ops on AffineRepr (arkworks-rs#756)

* Require `Neg`, `Sub`, `SubAssign` ops on `AffineRepr`

* Update CHANGELOG

Author: Pratyush

CHANGELOG.md

@@ -16,6 +16,7 @@
         - Make `windowed_mul` a private method of `BatchMulPreprocessing`.
         - Rename `get_mul_window_size` to `compute_window_size` and make it private.
 - [\#748](https://github.com/arkworks-rs/algebra/pull/748) (`ark-ff`) Add `FromStr` for `BigInteger`.
+- [\#756](https://github.com/arkworks-rs/algebra/pull/756) (`ark-ec`) Require `Neg`, `Sub`, `SubAssign` ops on `AffineRepr`.
 
 ### Features
 

ec/src/lib.rs

@@ -14,9 +14,6 @@
 )]
 #![doc = include_str!("../README.md")]
 
-#[macro_use]
-extern crate derivative;
-
 #[macro_use]
 extern crate ark_std;
 
@@ -28,7 +25,7 @@ use ark_serialize::{CanonicalDeserialize, CanonicalSerialize};
 use ark_std::{
     fmt::{Debug, Display},
     hash::Hash,
-    ops::{Add, AddAssign, Mul, MulAssign},
+    ops::{Add, AddAssign, Mul, MulAssign, Neg, Sub, SubAssign},
     vec::Vec,
 };
 pub use scalar_mul::{variable_base::VariableBaseMSM, ScalarMul};
@@ -82,8 +79,8 @@ pub trait CurveGroup:
     PrimeGroup
     + Add<Self::Affine, Output = Self>
     + AddAssign<Self::Affine>
-    // + for<'a> Add<&'a Self::Affine, Output = Self>
-    // + for<'a> AddAssign<&'a Self::Affine>
+    + Sub<Self::Affine, Output = Self>
+    + SubAssign<Self::Affine>
     + VariableBaseMSM
     + ScalarMul<MulBase = Self::Affine>
     + From<Self::Affine>
@@ -138,12 +135,17 @@ pub trait AffineRepr:
     + Debug
     + Display
     + Zeroize
+    + Neg
     + From<<Self as AffineRepr>::Group>
     + Into<<Self as AffineRepr>::Group>
     + Add<Self, Output = Self::Group>
     + for<'a> Add<&'a Self, Output = Self::Group>
     + Add<Self::Group, Output = Self::Group>
     + for<'a> Add<&'a Self::Group, Output = Self::Group>
+    + Sub<Self, Output = Self::Group>
+    + for<'a> Sub<&'a Self, Output = Self::Group>
+    + Sub<Self::Group, Output = Self::Group>
+    + for<'a> Sub<&'a Self::Group, Output = Self::Group>
     + Mul<Self::ScalarField, Output = Self::Group>
     + for<'a> Mul<&'a Self::ScalarField, Output = Self::Group>
 {

ec/src/models/bls12/g1.rs

@@ -5,6 +5,7 @@ use crate::{
 };
 use ark_serialize::{CanonicalDeserialize, CanonicalSerialize};
 use ark_std::vec::Vec;
+use derivative::Derivative;
 
 pub type G1Affine<P> = Affine<<P as Bls12Config>::G1Config>;
 pub type G1Projective<P> = Projective<<P as Bls12Config>::G1Config>;

ec/src/models/bls12/g2.rs

@@ -1,6 +1,7 @@
 use ark_ff::{AdditiveGroup, BitIteratorBE, Field, Fp2};
 use ark_serialize::{CanonicalDeserialize, CanonicalSerialize};
 use ark_std::{vec::Vec, One};
+use derivative::Derivative;
 
 use crate::{
     bls12::{Bls12Config, TwistType},

ec/src/models/bls12/mod.rs

@@ -12,7 +12,8 @@ use ark_ff::{
     },
     BitIteratorBE, CyclotomicMultSubgroup, Field, PrimeField,
 };
-use ark_std::{marker::PhantomData, vec::Vec};
+use ark_std::{cfg_chunks_mut, marker::PhantomData, vec::Vec};
+use derivative::Derivative;
 use num_traits::{One, Zero};
 
 #[cfg(feature = "parallel")]

ec/src/models/bn/g1.rs

@@ -5,6 +5,7 @@ use crate::{
 };
 use ark_serialize::{CanonicalDeserialize, CanonicalSerialize};
 use ark_std::vec::Vec;
+use derivative::Derivative;
 
 pub type G1Affine<P> = Affine<<P as BnConfig>::G1Config>;
 pub type G1Projective<P> = Projective<<P as BnConfig>::G1Config>;

ec/src/models/bn/g2.rs

@@ -4,6 +4,7 @@ use ark_ff::{
 };
 use ark_serialize::{CanonicalDeserialize, CanonicalSerialize};
 use ark_std::vec::Vec;
+use derivative::Derivative;
 use num_traits::One;
 
 use crate::{

ec/src/models/bn/mod.rs

@@ -11,7 +11,8 @@ use ark_ff::{
     },
     CyclotomicMultSubgroup,
 };
-use ark_std::{marker::PhantomData, vec::Vec};
+use ark_std::{cfg_chunks_mut, marker::PhantomData, vec::Vec};
+use derivative::Derivative;
 use itertools::Itertools;
 use num_traits::One;
 

ec/src/models/bw6/g1.rs

@@ -5,6 +5,7 @@ use crate::{
 };
 use ark_serialize::{CanonicalDeserialize, CanonicalSerialize};
 use ark_std::vec::Vec;
+use derivative::Derivative;
 
 pub type G1Affine<P> = Affine<<P as BW6Config>::G1Config>;
 pub type G1Projective<P> = Projective<<P as BW6Config>::G1Config>;

ec/src/models/bw6/g2.rs

@@ -1,6 +1,7 @@
 use ark_ff::{AdditiveGroup, BitIteratorBE, Field};
 use ark_serialize::{CanonicalDeserialize, CanonicalSerialize};
 use ark_std::vec::Vec;
+use derivative::Derivative;
 use num_traits::One;
 
 use crate::{

ec/src/models/bw6/mod.rs

@@ -10,6 +10,8 @@ use ark_ff::{
     },
     BitIteratorBE, CyclotomicMultSubgroup,
 };
+use ark_std::cfg_chunks_mut;
+use derivative::Derivative;
 use itertools::Itertools;
 use num_traits::One;
 

ec/src/models/mnt4/g1.rs

@@ -6,6 +6,7 @@ use crate::{
 use ark_ff::Fp2;
 use ark_serialize::{CanonicalDeserialize, CanonicalSerialize};
 use ark_std::vec::Vec;
+use derivative::Derivative;
 
 pub type G1Affine<P> = Affine<<P as MNT4Config>::G1Config>;
 pub type G1Projective<P> = Projective<<P as MNT4Config>::G1Config>;

ec/src/models/mnt4/g2.rs

@@ -8,7 +8,8 @@ use crate::{
 };
 use ark_ff::fields::{Field, Fp2};
 use ark_serialize::{CanonicalDeserialize, CanonicalSerialize};
-use ark_std::vec::Vec;
+use ark_std::{vec, vec::Vec};
+use derivative::Derivative;
 use num_traits::One;
 
 pub type G2Affine<P> = Affine<<P as MNT4Config>::G2Config>;

ec/src/models/mnt4/mod.rs

@@ -7,6 +7,7 @@ use ark_ff::{
     fp4::{Fp4, Fp4Config},
     AdditiveGroup, CyclotomicMultSubgroup, Field, PrimeField,
 };
+use derivative::Derivative;
 use itertools::Itertools;
 use num_traits::{One, Zero};
 
@@ -52,7 +53,7 @@ pub trait MNT4Config: 'static + Sized {
             .zip_eq(b)
             .map(|(a, b)| (a.into(), b.into()))
             .collect::<Vec<_>>();
-        let result = cfg_into_iter!(pairs)
+        let result = ark_std::cfg_into_iter!(pairs)
             .map(|(a, b)| MNT4::<Self>::ate_miller_loop(&a, &b))
             .product();
         MillerLoopOutput(result)

ec/src/models/mnt6/g1.rs

@@ -6,6 +6,7 @@ use crate::{
 use ark_ff::Fp3;
 use ark_serialize::{CanonicalDeserialize, CanonicalSerialize};
 use ark_std::vec::Vec;
+use derivative::Derivative;
 
 pub type G1Affine<P> = Affine<<P as MNT6Config>::G1Config>;
 pub type G1Projective<P> = Projective<<P as MNT6Config>::G1Config>;

ec/src/models/mnt6/g2.rs

@@ -7,6 +7,7 @@ use crate::{
 use ark_ff::fields::{Field, Fp3};
 use ark_serialize::{CanonicalDeserialize, CanonicalSerialize};
 use ark_std::{ops::Neg, vec::Vec};
+use derivative::Derivative;
 use num_traits::One;
 
 pub type G2Affine<P> = Affine<<P as MNT6Config>::G2Config>;

ec/src/models/mnt6/mod.rs

@@ -7,6 +7,7 @@ use ark_ff::{
     fp6_2over3::{Fp6, Fp6Config},
     AdditiveGroup, CyclotomicMultSubgroup, Field, PrimeField,
 };
+use derivative::Derivative;
 use itertools::Itertools;
 use num_traits::{One, Zero};
 
@@ -53,7 +54,7 @@ pub trait MNT6Config: 'static + Sized {
             .zip_eq(b)
             .map(|(a, b)| (a.into(), b.into()))
             .collect::<Vec<_>>();
-        let result = cfg_into_iter!(pairs)
+        let result = ark_std::cfg_into_iter!(pairs)
             .map(|(a, b)| MNT6::<Self>::ate_miller_loop(&a, &b))
             .product();
         MillerLoopOutput(result)

ec/src/models/short_weierstrass/affine.rs

@@ -16,6 +16,7 @@ use ark_std::{
 
 use ark_ff::{fields::Field, AdditiveGroup, PrimeField, ToConstraintField, UniformRand};
 
+use derivative::Derivative;
 use zeroize::Zeroize;
 
 use super::{Projective, SWCurveConfig, SWFlags};
@@ -301,6 +302,20 @@ impl<P: SWCurveConfig, T: Borrow<Self>> Sub<T> for Affine<P> {
     }
 }
 
+impl<P: SWCurveConfig> Sub<Projective<P>> for Affine<P> {
+    type Output = Projective<P>;
+    fn sub(self, other: Projective<P>) -> Projective<P> {
+        other - self
+    }
+}
+
+impl<'a, P: SWCurveConfig> Sub<&'a Projective<P>> for Affine<P> {
+    type Output = Projective<P>;
+    fn sub(self, other: &'a Projective<P>) -> Projective<P> {
+        *other - self
+    }
+}
+
 impl<P: SWCurveConfig> Default for Affine<P> {
     #[inline]
     fn default() -> Self {

ec/src/models/short_weierstrass/group.rs

@@ -17,6 +17,7 @@ use ark_std::{
 
 use ark_ff::{fields::Field, AdditiveGroup, PrimeField, ToConstraintField, UniformRand};
 
+use derivative::Derivative;
 use zeroize::Zeroize;
 
 #[cfg(feature = "parallel")]

ec/src/models/twisted_edwards/affine.rs

@@ -12,6 +12,7 @@ use ark_std::{
     },
     vec::Vec,
 };
+use derivative::Derivative;
 use num_traits::{One, Zero};
 use zeroize::Zeroize;
 
@@ -251,6 +252,20 @@ impl<P: TECurveConfig, T: Borrow<Self>> Sub<T> for Affine<P> {
     }
 }
 
+impl<P: TECurveConfig> Sub<Projective<P>> for Affine<P> {
+    type Output = Projective<P>;
+    fn sub(self, other: Projective<P>) -> Projective<P> {
+        other - self
+    }
+}
+
+impl<'a, P: TECurveConfig> Sub<&'a Projective<P>> for Affine<P> {
+    type Output = Projective<P>;
+    fn sub(self, other: &'a Projective<P>) -> Projective<P> {
+        *other - self
+    }
+}
+
 impl<P: TECurveConfig> Default for Affine<P> {
     #[inline]
     fn default() -> Self {

ec/src/models/twisted_edwards/group.rs

@@ -17,6 +17,7 @@ use ark_std::{
 
 use ark_ff::{fields::Field, AdditiveGroup, PrimeField, ToConstraintField, UniformRand};
 
+use derivative::Derivative;
 use zeroize::Zeroize;
 
 #[cfg(feature = "parallel")]

ec/src/pairing.rs

@@ -14,6 +14,7 @@ use ark_std::{
     vec::Vec,
     UniformRand, Zero,
 };
+use derivative::Derivative;
 use zeroize::Zeroize;
 
 use crate::{AffineRepr, CurveGroup, PrimeGroup, VariableBaseMSM};

ec/src/scalar_mul/variable_base/mod.rs

@@ -1,5 +1,5 @@
 use ark_ff::{prelude::*, PrimeField};
-use ark_std::{borrow::Borrow, iterable::Iterable, vec::Vec};
+use ark_std::{borrow::Borrow, cfg_into_iter, iterable::Iterable, vec::Vec};
 
 #[cfg(feature = "parallel")]
 use rayon::prelude::*;