From 53a51eb4dc5945f07b6c3a3923ab074edacd95c9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fran=C3=A7ois=20Garillot?= <francois@garillot.net>
Date: Mon, 2 Dec 2019 07:28:49 -0800
Subject: [PATCH] Use built-in iteration functions more

---
 crypto-primitives/src/crh/bowe_hopwood/mod.rs | 4 ++--
 crypto-primitives/src/crh/pedersen/mod.rs     | 2 +-
 r1cs-std/src/bits/boolean.rs                  | 2 +-
 r1cs-std/src/fields/mod.rs                    | 2 +-
 r1cs-std/src/lib.rs                           | 5 +----
 5 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/crypto-primitives/src/crh/bowe_hopwood/mod.rs b/crypto-primitives/src/crh/bowe_hopwood/mod.rs
index 8820600..61a21bf 100644
--- a/crypto-primitives/src/crh/bowe_hopwood/mod.rs
+++ b/crypto-primitives/src/crh/bowe_hopwood/mod.rs
@@ -144,9 +144,9 @@ impl<G: Group, W: PedersenWindow> FixedLengthCRH for BoweHopwoodPedersenCRH<G, W
                         }
                         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)
diff --git a/crypto-primitives/src/crh/pedersen/mod.rs b/crypto-primitives/src/crh/pedersen/mod.rs
index 6dbc731..4d37df3 100644
--- a/crypto-primitives/src/crh/pedersen/mod.rs
+++ b/crypto-primitives/src/crh/pedersen/mod.rs
@@ -111,7 +111,7 @@ impl<G: Group, W: PedersenWindow> FixedLengthCRH for PedersenCRH<G, W> {
                 }
                 encoded
             })
-            .reduce(|| G::zero(), |a, b| a + &b);
+            .reduce(G::zero, |a, b| a + &b);
         end_timer!(eval_time);
 
         Ok(result)
diff --git a/r1cs-std/src/bits/boolean.rs b/r1cs-std/src/bits/boolean.rs
index 5d2edac..33697ea 100644
--- a/r1cs-std/src/bits/boolean.rs
+++ b/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.
 
diff --git a/r1cs-std/src/fields/mod.rs b/r1cs-std/src/fields/mod.rs
index 271c1d2..e3204d3 100644
--- a/r1cs-std/src/fields/mod.rs
+++ b/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),
diff --git a/r1cs-std/src/lib.rs b/r1cs-std/src/lib.rs
index 1f500ca..775aca0 100644
--- a/r1cs-std/src/lib.rs
+++ b/r1cs-std/src/lib.rs
@@ -71,9 +71,6 @@ pub trait Assignment<T> {
 
 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 })
     }
 }