Move pedersen_hash() to go with the other Sapling hash functions, for now

zebra-chain/src/commitments/sapling.rs

@@ -55,8 +55,6 @@ pub fn pedersen_hash_to_point(domain: [u8; 8], M: &BitVec<Lsb0, u8>) -> jubjub::
     /// ⟨Mᵢ⟩
     ///
     /// Σ j={0,k-1}: (1 - 2x₂)⋅(1 + x₀ + 2x₁)⋅2^(4⋅j)
-    // XXX: Are internal functions doc'd?
-    //
     // This is less efficient than it could be so that it can match the math
     // closely.
     fn M_i(segment: &BitSlice<Lsb0, u8>) -> jubjub::Fr {
@@ -115,6 +113,14 @@ pub fn pedersen_hash_to_point(domain: [u8; 8], M: &BitVec<Lsb0, u8>) -> jubjub::
     result
 }
 
+/// Pedersen Hash Function
+///
+/// https://zips.z.cash/protocol/protocol.pdf#concretepedersenhash
+#[allow(non_snake_case)]
+pub fn pedersen_hash(domain: [u8; 8], M: &BitVec<Lsb0, u8>) -> jubjub::Fq {
+    jubjub::AffinePoint::from(pedersen_hash_to_point(domain, M)).get_u()
+}
+
 /// Mixing Pedersen Hash Function
 ///
 /// Used to compute ρ from a note commitment and its position in the note

zebra-chain/src/treestate/note_commitment_tree.rs

@@ -20,18 +20,10 @@ use bitvec::prelude::*;
 use proptest_derive::Arbitrary;
 
 use crate::{
-    commitments::sapling::pedersen_hash_to_point,
+    commitments::sapling::pedersen_hash,
     serialization::{SerializationError, ZcashDeserialize, ZcashSerialize},
 };
 
-/// Pedersen Hash Function
-///
-/// https://zips.z.cash/protocol/protocol.pdf#concretepedersenhash
-#[allow(non_snake_case)]
-fn pedersen_hash(domain: [u8; 8], M: &BitVec<Lsb0, u8>) -> jubjub::Fq {
-    jubjub::AffinePoint::from(pedersen_hash_to_point(domain, M)).get_u()
-}
-
 /// MerkleCRH^Sapling Hash Function
 ///
 /// MerkleCRH^Sapling(layer, left, right) := PedersenHash(“Zcash_PH”, l || left ||right)