Update trait impl w/ feedback

ec/src/lib.rs

@@ -311,6 +311,8 @@ pub fn prepare_g2<E: PairingEngine>(g: impl Into<E::G2Affine>) -> E::G2Prepared
 }
 
 /// A cycle of pairing-friendly elliptic curves.
+/// TODO: remove this once dependencies are
+/// updated with new curve cycle traits
 pub trait CycleEngine: Sized + 'static + Copy + Debug + Sync + Send
 where
  <Self::E2 as PairingEngine>::G1Projective: MulAssign<<Self::E1 as PairingEngine>::Fq>,
@@ -323,12 +325,34 @@ where
  >;
 }
 
-/// A cycle of elliptic curves, unopinionated
-pub trait SimpleCycleEngine: Sized + 'static + Copy + Debug + Sync + Send
+pub trait CurveCycle 
 where
  <Self::E1 as AffineCurve>::Projective: MulAssign<<Self::E2 as AffineCurve>::BaseField>,
  <Self::E2 as AffineCurve>::Projective: MulAssign<<Self::E1 as AffineCurve>::BaseField>,
 {
- type E1: AffineCurve;
+ // Maybe these constraints are too tight and could cause rust's constraint solver
+ // error out due to cycles (heh); we remove the
+ // bounds on the associated types if that's the case.
+ type E1: AffineCurve<
+ BaseField = <Self::E2 as AffineCurve>::ScalarField,
+ ScalarField = <Self::E2 as AffineCurve>::BaseField,
+ >;
  type E2: AffineCurve;
 }
+
+pub trait PairingFriendlyCycle: CurveCycle {
+ // add whatever extra bounds are necessary.
+ type Engine1: PairingEngine<
+ G1Affine = Self::E1,
+ G1Projective = <Self::E1 as AffineCurve>::Projective,
+ Fq = <Self::E1 as AffineCurve>::BaseField,
+ Fr = <Self::E1 as AffineCurve>::ScalarField,
+ >;
+
+ type Engine2: PairingEngine<
+ G2Affine = Self::E2,
+ G2Projective = <Self::E2 as AffineCurve>::Projective,
+ Fq = <Self::E2 as AffineCurve>::BaseField,
+ Fr = <Self::E2 as AffineCurve>::ScalarField,
+ >;
+}