Cleanups and clippy fixes

src/circuit/gadget/ecc/chip.rs

@@ -103,7 +103,7 @@ pub struct EccConfig {
 }
 
 /// A chip implementing EccInstructions
-#[derive(Debug)]
+#[derive(Clone, Debug)]
 pub struct EccChip<C: CurveAffine> {
     pub config: EccConfig,
     pub loaded: EccLoaded<C>,

src/circuit/gadget/ecc/chip/mul.rs

@@ -1,5 +1,6 @@
 use super::{add, double, util, CellValue, EccConfig, EccPoint};
 use crate::constants::NUM_COMPLETE_BITS;
+use std::ops::Deref;
 
 use ff::PrimeField;
 use halo2::{
@@ -55,8 +56,7 @@ pub(super) fn create_gate<F: FieldExt>(
     // y_{A,i+1} = (λ_{1,i+1} + λ_{2,i+1})
     //           * (x_{A,i+1} - (λ_{1,i+1}^2 - x_{A,i+1} - x_{P,i+1})) / 2
     let y_a_next = (lambda1_next.clone() + lambda2_next)
-        * (x_a_next.clone()
-            - (lambda1_next.clone() * lambda1_next - x_a_next.clone() - x_p_next.clone()))
+        * (x_a_next.clone() - (lambda1_next.clone() * lambda1_next - x_a_next.clone() - x_p_next))
         * F::TWO_INV;
 
     // λ_{1,i}⋅(x_{A,i} − x_{P,i}) − y_{A,i} + (2k_i - 1) y_{P,i} = 0
@@ -158,7 +158,7 @@ pub(super) fn assign_region<C: CurveAffine>(
 
     // Bits used in incomplete addition. k_{254} to k_{4} inclusive
     let incomplete_range = 0..(C::Scalar::NUM_BITS as usize - 1 - NUM_COMPLETE_BITS);
-    let k_incomplete = &k_bits[incomplete_range.clone()];
+    let k_incomplete = &k_bits[incomplete_range];
     let k_incomplete_hi = &k_incomplete[..k_incomplete.len() / 2];
     let k_incomplete_lo = &k_incomplete[k_incomplete.len() / 2..];
 
@@ -183,8 +183,7 @@ pub(super) fn assign_region<C: CurveAffine>(
         offset + 1,
         hi_columns,
         k_incomplete_hi,
-        z,
-        (acc.x.clone(), acc.y.value),
+        (X(acc.x.clone()), Y(acc.y.value), ZValue(z)),
     )?;
 
     // Double-and-add (incomplete addition) for the `lo` half of the scalar decomposition
@@ -195,8 +194,7 @@ pub(super) fn assign_region<C: CurveAffine>(
         offset + 1,
         lo_columns,
         k_incomplete_lo,
-        z,
-        (x, y_a),
+        (x, y_a, z),
     )?;
 
     // Move from incomplete addition to complete addition
@@ -219,8 +217,8 @@ pub(super) fn assign_region<C: CurveAffine>(
             &config.perm_sum,
         )?;
         EccPoint {
-            x,
-            y: CellValue::<C::Base>::new(y_a_cell, y_a),
+            x: x.0,
+            y: CellValue::<C::Base>::new(y_a_cell, *y_a),
         }
     };
 
@@ -332,7 +330,7 @@ pub(super) fn assign_region<C: CurveAffine>(
         };
 
         // Return the result of the final complete addition as `[scalar]B`
-        add::assign_region::<C>(&p, &acc, k_0_row + offset, region, config.clone())
+        add::assign_region::<C>(&p, &acc, k_0_row + offset, region, config)
     } else {
         // If `k_0` is 1, simply return `Acc`
         Ok(acc)
@@ -347,6 +345,36 @@ struct IncompleteColumns {
     lambda: (Column<Advice>, Column<Advice>),
 }
 
+#[derive(Clone, Debug)]
+struct X<F: FieldExt>(CellValue<F>);
+impl<F: FieldExt> Deref for X<F> {
+    type Target = CellValue<F>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+#[derive(Copy, Clone, Debug)]
+struct Y<F: FieldExt>(Option<F>);
+impl<F: FieldExt> Deref for Y<F> {
+    type Target = Option<F>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+#[derive(Clone, Debug)]
+struct ZValue<F: FieldExt>(CellValue<F>);
+impl<F: FieldExt> Deref for ZValue<F> {
+    type Target = CellValue<F>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
 // We perform incomplete addition on all but the last three bits of the
 // decomposed scalar.
 // We split the bits in the incomplete addition range into "hi" and "lo"
@@ -360,13 +388,12 @@ fn add_incomplete<C: CurveAffine>(
     offset: usize,
     columns: IncompleteColumns,
     bits: &[bool],
-    starting_z: CellValue<C::Base>,
-    acc: (CellValue<C::Base>, Option<C::Base>),
-) -> Result<(CellValue<C::Base>, Option<C::Base>, CellValue<C::Base>), Error> {
+    acc: (X<C::Base>, Y<C::Base>, ZValue<C::Base>),
+) -> Result<(X<C::Base>, Y<C::Base>, ZValue<C::Base>), Error> {
     // Initialise the running `z` sum for the scalar bits.
-    let mut z_val = starting_z.value.unwrap();
+    let mut z_val = acc.2.value.unwrap();
     let mut z_cell = region.assign_advice(|| "starting z", columns.z, offset, || Ok(z_val))?;
-    region.constrain_equal(&config.perm_sum, z_cell, starting_z.cell)?;
+    region.constrain_equal(&config.perm_sum, z_cell, acc.2.cell)?;
 
     let offset = offset + 1;
 
@@ -379,7 +406,7 @@ fn add_incomplete<C: CurveAffine>(
         || x_a.ok_or(Error::SynthesisError),
     )?;
     region.constrain_equal(&config.perm_sum, x_a_cell, acc.0.cell)?;
-    let mut y_a = acc.1;
+    let mut y_a = *acc.1;
 
     // Enable `q_mul` on all but the last row of the incomplete range.
     for row in 1..(bits.len() - 1) {
@@ -461,9 +488,9 @@ fn add_incomplete<C: CurveAffine>(
         )?;
     }
     Ok((
-        CellValue::<C::Base>::new(x_a_cell, x_a),
-        y_a,
-        CellValue::<C::Base>::new(z_cell, Some(z_val)),
+        X(CellValue::<C::Base>::new(x_a_cell, x_a)),
+        Y(y_a),
+        ZValue(CellValue::<C::Base>::new(z_cell, Some(z_val))),
     ))
 }