From bc20c5826b3755bbcaf8555b748aa4da32d024b6 Mon Sep 17 00:00:00 2001
From: Jack Grigg <jack@electriccoin.co>
Date: Tue, 1 Jun 2021 23:31:00 +0100
Subject: [PATCH] Migrate to ff 0.10.0

---
 Cargo.toml       |  9 +++++----
 src/fields/fp.rs | 46 ++++++++++++++++++++++++++--------------------
 src/fields/fq.rs | 46 ++++++++++++++++++++++++++--------------------
 3 files changed, 57 insertions(+), 44 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index bdb9213..c0571f5 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -39,12 +39,13 @@ harness = false
 
 [dependencies]
 subtle = "2.3"
-ff = "0.9"
-group = "0.9"
+ff = "0.10"
+group = "0.10"
 rand = "0.8"
 blake2b_simd = "0.5"
 lazy_static = "1.4.0"
 static_assertions = "1.1.0"
 
-# Temporary workaround for https://github.com/myrrlyn/funty/issues/3
-funty = "=1.1.0"
+[features]
+default = ["bits"]
+bits = ["ff/bits"]
diff --git a/src/fields/fp.rs b/src/fields/fp.rs
index 406d76c..d72b0ee 100644
--- a/src/fields/fp.rs
+++ b/src/fields/fp.rs
@@ -1,11 +1,13 @@
 use core::convert::TryInto;
 use core::fmt;
 use core::ops::{Add, Mul, Neg, Sub};
-use ff::FieldBits;
 use lazy_static::lazy_static;
 use rand::RngCore;
 use subtle::{Choice, ConditionallySelectable, ConstantTimeEq, CtOption};
 
+#[cfg(feature = "bits")]
+use ff::{FieldBits, PrimeFieldBits};
+
 use crate::arithmetic::{adc, mac, sbb, FieldExt, Group, SqrtTables};
 
 /// This represents an element of $\mathbb{F}_p$ where
@@ -529,15 +531,8 @@ impl ff::Field for Fp {
     }
 }
 
-#[cfg(not(target_pointer_width = "64"))]
-type ReprBits = [u32; 8];
-
-#[cfg(target_pointer_width = "64")]
-type ReprBits = [u64; 4];
-
 impl ff::PrimeField for Fp {
     type Repr = [u8; 32];
-    type ReprBits = ReprBits;
 
     const NUM_BITS: u32 = 255;
     const CAPACITY: u32 = 254;
@@ -551,6 +546,29 @@ impl ff::PrimeField for Fp {
         self.to_bytes()
     }
 
+    fn is_odd(&self) -> bool {
+        self.to_bytes()[0] & 1 == 1
+    }
+
+    fn multiplicative_generator() -> Self {
+        GENERATOR
+    }
+
+    fn root_of_unity() -> Self {
+        Self::ROOT_OF_UNITY
+    }
+}
+
+#[cfg(all(feature = "bits", not(target_pointer_width = "64")))]
+type ReprBits = [u32; 8];
+
+#[cfg(all(feature = "bits", target_pointer_width = "64"))]
+type ReprBits = [u64; 4];
+
+#[cfg(feature = "bits")]
+impl PrimeFieldBits for Fp {
+    type ReprBits = ReprBits;
+
     fn to_le_bits(&self) -> FieldBits<Self::ReprBits> {
         let bytes = self.to_bytes();
 
@@ -577,10 +595,6 @@ impl ff::PrimeField for Fp {
         FieldBits::new(limbs)
     }
 
-    fn is_odd(&self) -> bool {
-        self.to_bytes()[0] & 1 == 1
-    }
-
     fn char_le_bits() -> FieldBits<Self::ReprBits> {
         #[cfg(not(target_pointer_width = "64"))]
         {
@@ -590,14 +604,6 @@ impl ff::PrimeField for Fp {
         #[cfg(target_pointer_width = "64")]
         FieldBits::new(MODULUS.0)
     }
-
-    fn multiplicative_generator() -> Self {
-        GENERATOR
-    }
-
-    fn root_of_unity() -> Self {
-        Self::ROOT_OF_UNITY
-    }
 }
 
 lazy_static! {
diff --git a/src/fields/fq.rs b/src/fields/fq.rs
index cc8954a..3bf0b1f 100644
--- a/src/fields/fq.rs
+++ b/src/fields/fq.rs
@@ -1,11 +1,13 @@
 use core::convert::TryInto;
 use core::fmt;
 use core::ops::{Add, Mul, Neg, Sub};
-use ff::FieldBits;
 use lazy_static::lazy_static;
 use rand::RngCore;
 use subtle::{Choice, ConditionallySelectable, ConstantTimeEq, CtOption};
 
+#[cfg(feature = "bits")]
+use ff::{FieldBits, PrimeFieldBits};
+
 use crate::arithmetic::{adc, mac, sbb, FieldExt, Group, SqrtTables};
 
 /// This represents an element of $\mathbb{F}_q$ where
@@ -529,15 +531,8 @@ impl ff::Field for Fq {
     }
 }
 
-#[cfg(not(target_pointer_width = "64"))]
-type ReprBits = [u32; 8];
-
-#[cfg(target_pointer_width = "64")]
-type ReprBits = [u64; 4];
-
 impl ff::PrimeField for Fq {
     type Repr = [u8; 32];
-    type ReprBits = ReprBits;
 
     const NUM_BITS: u32 = 255;
     const CAPACITY: u32 = 254;
@@ -551,6 +546,29 @@ impl ff::PrimeField for Fq {
         self.to_bytes()
     }
 
+    fn is_odd(&self) -> bool {
+        self.to_bytes()[0] & 1 == 1
+    }
+
+    fn multiplicative_generator() -> Self {
+        GENERATOR
+    }
+
+    fn root_of_unity() -> Self {
+        Self::ROOT_OF_UNITY
+    }
+}
+
+#[cfg(all(feature = "bits", not(target_pointer_width = "64")))]
+type ReprBits = [u32; 8];
+
+#[cfg(all(feature = "bits", target_pointer_width = "64"))]
+type ReprBits = [u64; 4];
+
+#[cfg(feature = "bits")]
+impl PrimeFieldBits for Fq {
+    type ReprBits = ReprBits;
+
     fn to_le_bits(&self) -> FieldBits<Self::ReprBits> {
         let bytes = self.to_bytes();
 
@@ -577,10 +595,6 @@ impl ff::PrimeField for Fq {
         FieldBits::new(limbs)
     }
 
-    fn is_odd(&self) -> bool {
-        self.to_bytes()[0] & 1 == 1
-    }
-
     fn char_le_bits() -> FieldBits<Self::ReprBits> {
         #[cfg(not(target_pointer_width = "64"))]
         {
@@ -590,14 +604,6 @@ impl ff::PrimeField for Fq {
         #[cfg(target_pointer_width = "64")]
         FieldBits::new(MODULUS.0)
     }
-
-    fn multiplicative_generator() -> Self {
-        GENERATOR
-    }
-
-    fn root_of_unity() -> Self {
-        Self::ROOT_OF_UNITY
-    }
 }
 
 lazy_static! {