Use built-in iteration functions more

crypto-primitives/src/crh/bowe_hopwood/mod.rs

@@ -144,9 +144,9 @@ impl FixedLengthCRH for BoweHopwoodPedersenCRH
                         }
                         encoded
                     })
-                    .reduce(|| G::zero(), |a, b| a + &b)
+                    .reduce(G::zero, |a, b| a + &b)
             })
-            .reduce(|| G::zero(), |a, b| a + &b);
+            .reduce(G::zero, |a, b| a + &b);
         end_timer!(eval_time);
 
         Ok(result)

crypto-primitives/src/crh/pedersen/mod.rs

@@ -111,7 +111,7 @@ impl FixedLengthCRH for PedersenCRH {
                 }
                 encoded
             })
-            .reduce(|| G::zero(), |a, b| a + &b);
+            .reduce(G::zero, |a, b| a + &b);
         end_timer!(eval_time);
 
         Ok(result)

r1cs-std/src/bits/boolean.rs

@@ -586,7 +586,7 @@ impl Boolean {
                 // This is part of a run of ones.
                 current_run.push(a.clone());
             } else {
-                if current_run.len() > 0 {
+                if !current_run.is_empty() {
                     // This is the start of a run of zeros, but we need
                     // to k-ary AND against `last_run` first.
 

r1cs-std/src/fields/mod.rs

@@ -405,7 +405,7 @@ mod test {
         assert_eq!(a_inv.get_value().unwrap(), a_native.inverse().unwrap());
         // a * a * a = a^3
         let bits = BitIterator::new([0x3])
-            .map(|bit| Boolean::constant(bit))
+            .map(Boolean::constant)
             .collect::<Vec<_>>();
         assert_eq!(
             a_native * &(a_native * &a_native),

r1cs-std/src/lib.rs

@@ -71,9 +71,6 @@ pub trait Assignment {
 
 impl<T> Assignment<T> for Option<T> {
     fn get(self) -> Result<T, r1cs_core::SynthesisError> {
-        match self {
-            Some(v) => Ok(v),
-            None => Err(r1cs_core::SynthesisError::AssignmentMissing),
-        }
+        self.ok_or_else(|| { r1cs_core::SynthesisError::AssignmentMissing })
     }
 }