[#1793] Add minimal FFAInterpreterEnv

msm/src/ffa/interpreter.rs

@@ -0,0 +1,17 @@
+use ark_ff::PrimeField;
+
+pub trait FFAInterpreterEnv<Fp: PrimeField> {
+    type Position;
+
+    type Variable: Clone
+        + std::ops::Add<Self::Variable, Output = Self::Variable>
+        + std::ops::Sub<Self::Variable, Output = Self::Variable>
+        + std::ops::Mul<Self::Variable, Output = Self::Variable>
+        + std::fmt::Debug;
+
+    fn add_constraint(&mut self, cst: Self::Variable);
+
+    fn copy(&mut self, x: &Self::Variable, position: Self::Position) -> Self::Variable;
+
+    fn constant(value: Fp) -> Self::Variable;
+}

msm/src/ffa/mod.rs

@@ -1,4 +1,4 @@
 pub mod columns;
 pub mod constraint;
-//pub mod interpreter;
+pub mod interpreter;
 pub mod witness;