Simplify implementation of addmany.

src/circuit/boolean.rs

@@ -367,6 +367,13 @@ pub enum Boolean {
 }
 
 impl Boolean {
+    pub fn is_constant(&self) -> bool {
+        match *self {
+            Boolean::Constant(_) => true,
+            _ => false
+        }
+    }
+
     pub fn enforce_equal<E, CS>(
         mut cs: CS,
         a: &Self,

src/circuit/uint32.rs

@@ -418,25 +418,9 @@ impl UInt32 {
             // the linear combination
             let mut coeff = E::Fr::one();
             for bit in &op.bits {
-                match bit {
-                    &Boolean::Is(ref bit) => {
-                        all_constants = false;
+                lc = lc + &bit.lc(CS::one(), coeff);
 
-                        // Add coeff * bit
-                        lc = lc + (coeff, bit.get_variable());
-                    },
-                    &Boolean::Not(ref bit) => {
-                        all_constants = false;
-
-                        // Add coeff * (1 - bit) = coeff * ONE - coeff * bit
-                        lc = lc + (coeff, CS::one()) - (coeff, bit.get_variable());
-                    },
-                    &Boolean::Constant(bit) => {
-                        if bit {
-                            lc = lc + (coeff, CS::one());
-                        }
-                    }
-                }
+                all_constants &= bit.is_constant();
 
                 coeff.double();
             }