From b617d217a18c70eeeb667aa56c3fb7058748db55 Mon Sep 17 00:00:00 2001
From: Pratyush Mishra <pratyushmishra@berkeley.edu>
Date: Mon, 12 Aug 2019 18:05:24 -0700
Subject: [PATCH] Move ConstraintVar to r1cs-core

---
 r1cs-std/src/fields/fp.rs         |  14 +-
 r1cs-std/src/fields/fp2.rs        |   4 +-
 r1cs-std/src/fields/fp6_3over2.rs |   3 +-
 r1cs-std/src/lib.rs               | 288 +-----------------------------
 4 files changed, 9 insertions(+), 300 deletions(-)

diff --git a/r1cs-std/src/fields/fp.rs b/r1cs-std/src/fields/fp.rs
index b78204a..fc6403d 100644
--- a/r1cs-std/src/fields/fp.rs
+++ b/r1cs-std/src/fields/fp.rs
@@ -1,20 +1,12 @@
 use algebra::{bytes::ToBytes, FpParameters, PrimeField};
-use r1cs_core::{ConstraintSystem, LinearCombination, SynthesisError};
+use r1cs_core::{ConstraintSystem, LinearCombination, SynthesisError, ConstraintVar::{self, *}};
 
 use std::borrow::Borrow;
 
-use super::FieldGadget;
-use crate::{
-    boolean::{AllocatedBit, Boolean},
-    uint8::UInt8,
-};
-
+use crate::boolean::AllocatedBit;
+use crate::Assignment;
 use crate::prelude::*;
 
-use crate::{
-    Assignment,
-    ConstraintVar::{self, *},
-};
 
 #[derive(Debug)]
 pub struct FpGadget<F: PrimeField> {
diff --git a/r1cs-std/src/fields/fp2.rs b/r1cs-std/src/fields/fp2.rs
index ebf2ec9..26e8a08 100644
--- a/r1cs-std/src/fields/fp2.rs
+++ b/r1cs-std/src/fields/fp2.rs
@@ -2,12 +2,12 @@ use algebra::{
     fields::{Fp2, Fp2Parameters},
     Field, PrimeField,
 };
-use r1cs_core::{ConstraintSystem, SynthesisError};
+use r1cs_core::{ConstraintSystem, SynthesisError, ConstraintVar};
 use std::{borrow::Borrow, marker::PhantomData};
 
 use crate::fields::fp::FpGadget;
 use crate::prelude::*;
-use crate::{Assignment, ConstraintVar};
+use crate::Assignment;
 
 #[derive(Derivative)]
 #[derivative(Debug(bound = "P: Fp2Parameters, ConstraintF: PrimeField"))]
diff --git a/r1cs-std/src/fields/fp6_3over2.rs b/r1cs-std/src/fields/fp6_3over2.rs
index 22c15cb..01f3600 100644
--- a/r1cs-std/src/fields/fp6_3over2.rs
+++ b/r1cs-std/src/fields/fp6_3over2.rs
@@ -5,11 +5,10 @@ use algebra::{
     },
     PrimeField,
 };
-use r1cs_core::{ConstraintSystem, SynthesisError};
+use r1cs_core::{ConstraintSystem, SynthesisError, ConstraintVar};
 use std::{borrow::Borrow, marker::PhantomData};
 
 use crate::prelude::*;
-use crate::ConstraintVar;
 use crate::Assignment;
 
 type Fp2Gadget<P, ConstraintF> = super::fp2::Fp2Gadget<<P as Fp6Parameters>::Fp2Params, ConstraintF>;
diff --git a/r1cs-std/src/lib.rs b/r1cs-std/src/lib.rs
index d60bc96..fc35d68 100644
--- a/r1cs-std/src/lib.rs
+++ b/r1cs-std/src/lib.rs
@@ -38,11 +38,6 @@ extern crate algebra;
 #[macro_use]
 extern crate derivative;
 
-use crate::ConstraintVar::*;
-use algebra::Field;
-use r1cs_core::{LinearCombination, SynthesisError, Variable};
-use std::ops::{Add, AddAssign, Mul, MulAssign, Neg, Sub};
-
 pub mod test_constraint_system;
 
 pub mod bits;
@@ -69,291 +64,14 @@ pub mod prelude {
 }
 
 pub trait Assignment<T> {
-    fn get(self) -> Result<T, SynthesisError>;
+    fn get(self) -> Result<T, r1cs_core::SynthesisError>;
 }
 
 impl<T> Assignment<T> for Option<T> {
-    fn get(self) -> Result<T, SynthesisError> {
+    fn get(self) -> Result<T, r1cs_core::SynthesisError> {
         match self {
             Some(v) => Ok(v),
-            None => Err(SynthesisError::AssignmentMissing),
-        }
-    }
-}
-
-#[derive(Clone, Debug)]
-pub enum ConstraintVar<F: Field> {
-    LC(LinearCombination<F>),
-    Var(Variable),
-}
-
-impl<F: Field> From<Variable> for ConstraintVar<F> {
-    #[inline]
-    fn from(var: Variable) -> Self {
-        Var(var)
-    }
-}
-
-impl<F: Field> From<(F, Variable)> for ConstraintVar<F> {
-    #[inline]
-    fn from(coeff_var: (F, Variable)) -> Self {
-        LC(coeff_var.into())
-    }
-}
-
-impl<F: Field> From<(F, LinearCombination<F>)> for ConstraintVar<F> {
-    #[inline]
-    fn from((coeff, mut lc): (F, LinearCombination<F>)) -> Self {
-        lc *= coeff;
-        LC(lc)
-    }
-}
-
-impl<F: Field> From<(F, ConstraintVar<F>)> for ConstraintVar<F> {
-    #[inline]
-    fn from((coeff, var): (F, ConstraintVar<F>)) -> Self {
-        match var {
-            LC(lc) => (coeff, lc).into(),
-            Var(var) => (coeff, var).into(),
-        }
-    }
-}
-
-impl<F: Field> ConstraintVar<F> {
-    #[inline]
-    pub fn zero() -> Self {
-        LC(LinearCombination::zero())
-    }
-
-    pub fn negate_in_place(&mut self) {
-        match self {
-            LC(ref mut lc) => lc.negate_in_place(),
-            Var(var) => *self = (-F::one(), *var).into(),
-        }
-    }
-
-    pub fn double_in_place(&mut self) {
-        match self {
-            LC(lc) => lc.double_in_place(),
-            Var(var) => *self = (F::one().double(), *var).into(),
+            None => Err(r1cs_core::SynthesisError::AssignmentMissing),
         }
     }
 }
-
-impl<F: Field> Add<LinearCombination<F>> for ConstraintVar<F> {
-    type Output = LinearCombination<F>;
-
-    #[inline]
-    fn add(self, other_lc: LinearCombination<F>) -> LinearCombination<F> {
-        match self {
-            LC(lc) => other_lc + lc,
-            Var(var) => other_lc + var,
-        }
-    }
-}
-
-impl<F: Field> Sub<LinearCombination<F>> for ConstraintVar<F> {
-    type Output = LinearCombination<F>;
-
-    #[inline]
-    fn sub(self, other_lc: LinearCombination<F>) -> LinearCombination<F> {
-        let result = match self {
-            LC(lc) => other_lc - lc,
-            Var(var) => other_lc - var,
-        };
-        -result
-    }
-}
-
-impl<F: Field> Add<LinearCombination<F>> for &ConstraintVar<F> {
-    type Output = LinearCombination<F>;
-
-    #[inline]
-    fn add(self, other_lc: LinearCombination<F>) -> LinearCombination<F> {
-        match self {
-            LC(lc) => other_lc + lc,
-            Var(var) => other_lc + *var,
-        }
-    }
-}
-
-impl<F: Field> Sub<LinearCombination<F>> for &ConstraintVar<F> {
-    type Output = LinearCombination<F>;
-
-    #[inline]
-    fn sub(self, other_lc: LinearCombination<F>) -> LinearCombination<F> {
-        let result = match self {
-            LC(lc) => other_lc - lc,
-            Var(var) => other_lc - *var,
-        };
-        -result
-    }
-}
-
-impl<F: Field> Add<(F, Variable)> for ConstraintVar<F> {
-    type Output = Self;
-
-    #[inline]
-    fn add(self, var: (F, Variable)) -> Self {
-        let lc = match self {
-            LC(lc) => lc + var,
-            Var(var2) => LinearCombination::from(var2) + var,
-        };
-        LC(lc)
-    }
-}
-
-impl<F: Field> AddAssign<(F, Variable)> for ConstraintVar<F> {
-    #[inline]
-    fn add_assign(&mut self, var: (F, Variable)) {
-        match self {
-            LC(ref mut lc) => *lc += var,
-            Var(var2) => *self = LC(LinearCombination::from(*var2) + var),
-        };
-    }
-}
-
-impl<F: Field> Neg for ConstraintVar<F> {
-    type Output = Self;
-
-    #[inline]
-    fn neg(mut self) -> Self {
-        self.negate_in_place();
-        self
-    }
-}
-
-impl<F: Field> Mul<F> for ConstraintVar<F> {
-    type Output = Self;
-
-    #[inline]
-    fn mul(self, scalar: F) -> Self {
-        match self {
-            LC(lc) => LC(lc * scalar),
-            Var(var) => (scalar, var).into(),
-        }
-    }
-}
-
-impl<F: Field> MulAssign<F> for ConstraintVar<F> {
-    #[inline]
-    fn mul_assign(&mut self, scalar: F) {
-        match self {
-            LC(lc) => *lc *= scalar,
-            Var(var) => *self = (scalar, *var).into(),
-        }
-    }
-}
-
-impl<F: Field> Sub<(F, Variable)> for ConstraintVar<F> {
-    type Output = Self;
-
-    #[inline]
-    fn sub(self, (coeff, var): (F, Variable)) -> Self {
-        self + (-coeff, var)
-    }
-}
-
-impl<F: Field> Add<Variable> for ConstraintVar<F> {
-    type Output = Self;
-
-    fn add(self, other: Variable) -> Self {
-        self + (F::one(), other)
-    }
-}
-
-impl<F: Field> Sub<Variable> for ConstraintVar<F> {
-    type Output = Self;
-
-    #[inline]
-    fn sub(self, other: Variable) -> Self {
-        self - (F::one(), other)
-    }
-}
-
-impl<'a, F: Field> Add<&'a Self> for ConstraintVar<F> {
-    type Output = Self;
-
-    #[inline]
-    fn add(self, other: &'a Self) -> Self {
-        let lc = match self {
-            LC(lc2) => lc2,
-            Var(var) => var.into(),
-        };
-        let lc2 = match other {
-            LC(lc2) => lc + lc2,
-            Var(var) => lc + *var,
-        };
-        LC(lc2)
-    }
-}
-
-impl<'a, F: Field> Sub<&'a Self> for ConstraintVar<F> {
-    type Output = Self;
-
-    #[inline]
-    fn sub(self, other: &'a Self) -> Self {
-        let lc = match self {
-            LC(lc2) => lc2,
-            Var(var) => var.into(),
-        };
-        let lc2 = match other {
-            LC(lc2) => lc - lc2,
-            Var(var) => lc - *var,
-        };
-        LC(lc2)
-    }
-}
-
-impl<F: Field> Add<&ConstraintVar<F>> for &ConstraintVar<F> {
-    type Output = ConstraintVar<F>;
-
-    #[inline]
-    fn add(self, other: &ConstraintVar<F>) -> Self::Output {
-        (ConstraintVar::zero() + self) + other
-    }
-}
-
-impl<F: Field> Sub<&ConstraintVar<F>> for &ConstraintVar<F> {
-    type Output = ConstraintVar<F>;
-
-    #[inline]
-    fn sub(self, other: &ConstraintVar<F>) -> Self::Output {
-        (ConstraintVar::zero() + self) - other
-    }
-}
-
-impl<'a, F: Field> Add<(F, &'a Self)> for ConstraintVar<F> {
-    type Output = Self;
-
-    #[inline]
-    fn add(self, (coeff, other): (F, &'a Self)) -> Self {
-        let mut lc = match self {
-            LC(lc2) => lc2,
-            Var(var) => LinearCombination::zero() + var,
-        };
-
-        lc = match other {
-            LC(lc2) => lc + (coeff, lc2),
-            Var(var) => lc + (coeff, *var),
-        };
-        LC(lc)
-    }
-}
-
-impl<'a, F: Field> Sub<(F, &'a Self)> for ConstraintVar<F> {
-    type Output = Self;
-
-    #[inline]
-    fn sub(self, (coeff, other): (F, &'a Self)) -> Self {
-        let mut lc = match self {
-            LC(lc2) => lc2,
-            Var(var) => LinearCombination::zero() + var,
-        };
-        lc = match other {
-            LC(lc2) => lc - (coeff, lc2),
-            Var(var) => lc - (coeff, *var),
-        };
-        LC(lc)
-    }
-}