From a63e14f4ded078d6bf262ba0b3f47026bdd7f7c0 Mon Sep 17 00:00:00 2001
From: Jordan Rose <jrose@signal.org>
Date: Mon, 13 Mar 2023 20:42:01 -0700
Subject: [PATCH] Use ok_or_else instead of ok_or in serde decoding (#382)

Serde errors are not simple enums; they format a full error string
from their arguments. It's worth not doing that up front.
---
 src/edwards.rs   | 6 +++---
 src/ristretto.rs | 6 +++---
 src/scalar.rs    | 2 +-
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/edwards.rs b/src/edwards.rs
index 06ce8ce5d..29c936126 100644
--- a/src/edwards.rs
+++ b/src/edwards.rs
@@ -288,11 +288,11 @@ impl<'de> Deserialize<'de> for EdwardsPoint {
                 for i in 0..32 {
                     bytes[i] = seq
                         .next_element()?
-                        .ok_or(serde::de::Error::invalid_length(i, &"expected 32 bytes"))?;
+                        .ok_or_else(|| serde::de::Error::invalid_length(i, &"expected 32 bytes"))?;
                 }
                 CompressedEdwardsY(bytes)
                     .decompress()
-                    .ok_or(serde::de::Error::custom("decompression failed"))
+                    .ok_or_else(|| serde::de::Error::custom("decompression failed"))
             }
         }
 
@@ -323,7 +323,7 @@ impl<'de> Deserialize<'de> for CompressedEdwardsY {
                 for i in 0..32 {
                     bytes[i] = seq
                         .next_element()?
-                        .ok_or(serde::de::Error::invalid_length(i, &"expected 32 bytes"))?;
+                        .ok_or_else(|| serde::de::Error::invalid_length(i, &"expected 32 bytes"))?;
                 }
                 Ok(CompressedEdwardsY(bytes))
             }
diff --git a/src/ristretto.rs b/src/ristretto.rs
index 95e30d41d..705bb91d4 100644
--- a/src/ristretto.rs
+++ b/src/ristretto.rs
@@ -409,11 +409,11 @@ impl<'de> Deserialize<'de> for RistrettoPoint {
                 for i in 0..32 {
                     bytes[i] = seq
                         .next_element()?
-                        .ok_or(serde::de::Error::invalid_length(i, &"expected 32 bytes"))?;
+                        .ok_or_else(|| serde::de::Error::invalid_length(i, &"expected 32 bytes"))?;
                 }
                 CompressedRistretto(bytes)
                     .decompress()
-                    .ok_or(serde::de::Error::custom("decompression failed"))
+                    .ok_or_else(|| serde::de::Error::custom("decompression failed"))
             }
         }
 
@@ -444,7 +444,7 @@ impl<'de> Deserialize<'de> for CompressedRistretto {
                 for i in 0..32 {
                     bytes[i] = seq
                         .next_element()?
-                        .ok_or(serde::de::Error::invalid_length(i, &"expected 32 bytes"))?;
+                        .ok_or_else(|| serde::de::Error::invalid_length(i, &"expected 32 bytes"))?;
                 }
                 Ok(CompressedRistretto(bytes))
             }
diff --git a/src/scalar.rs b/src/scalar.rs
index 58c71e4d9..f76d97962 100644
--- a/src/scalar.rs
+++ b/src/scalar.rs
@@ -478,7 +478,7 @@ impl<'de> Deserialize<'de> for Scalar {
                 for i in 0..32 {
                     bytes[i] = seq
                         .next_element()?
-                        .ok_or(serde::de::Error::invalid_length(i, &"expected 32 bytes"))?;
+                        .ok_or_else(|| serde::de::Error::invalid_length(i, &"expected 32 bytes"))?;
                 }
                 Option::from(Scalar::from_canonical_bytes(bytes))
                     .ok_or_else(|| serde::de::Error::custom(&"scalar was not canonically encoded"))