style(genesis_block): Avoid mutable tx variablk

Co-authored-by: Alan Szepieniec <[email protected]>

src/models/blockchain/block/mod.rs

@@ -324,25 +324,15 @@ impl Block {
     }
 
     pub fn genesis_block(network: Network) -> Self {
-        let mut genesis_mutator_set = MutatorSetAccumulator::default();
-        let mut ms_update = MutatorSetUpdate::default();
-
         let premine_distribution = Self::premine_distribution(network);
         let total_premine_amount = premine_distribution
             .iter()
             .map(|(_receiving_address, amount)| *amount)
             .sum();
 
-        let mut genesis_txk = TransactionKernel {
-            inputs: vec![],
-            outputs: vec![],
-            fee: NeptuneCoins::new(0),
-            timestamp: network.launch_date(),
-            public_announcements: vec![],
-            coinbase: Some(total_premine_amount),
-            mutator_set_hash: MutatorSetAccumulator::default().hash(),
-        };
-
+        let mut ms_update = MutatorSetUpdate::default();
+        let mut genesis_mutator_set = MutatorSetAccumulator::default();
+        let mut genesis_tx_outputs = vec![];
         for ((receiving_address, _amount), utxo) in premine_distribution
             .iter()
             .zip(Self::premine_utxos(network))
@@ -359,9 +349,19 @@ impl Block {
             genesis_mutator_set.add(&addition_record);
 
             // Add pre-mine UTXO + commitment to coinbase transaction
-            genesis_txk.outputs.push(addition_record)
+            genesis_tx_outputs.push(addition_record)
         }
 
+        let genesis_txk = TransactionKernel {
+            inputs: vec![],
+            outputs: genesis_tx_outputs,
+            fee: NeptuneCoins::new(0),
+            timestamp: network.launch_date(),
+            public_announcements: vec![],
+            coinbase: Some(total_premine_amount),
+            mutator_set_hash: MutatorSetAccumulator::default().hash(),
+        };
+
         let body: BlockBody = BlockBody {
             transaction_kernel: genesis_txk,
             mutator_set_accumulator: genesis_mutator_set.clone(),

src/models/blockchain/transaction/transaction_kernel.rs

@@ -38,16 +38,17 @@ pub fn pseudorandom_public_announcement(seed: [u8; 32]) -> PublicAnnouncement {
 pub struct TransactionKernel {
     pub inputs: Vec<RemovalRecord>,
 
-    // `outputs` contains the commitments (addition records) that go into the AOCL
+    /// `outputs` contains the commitments (addition records) that go into the AOCL
     pub outputs: Vec<AdditionRecord>,
 
     pub public_announcements: Vec<PublicAnnouncement>,
     pub fee: NeptuneCoins,
     pub coinbase: Option<NeptuneCoins>,
 
-    // number of milliseconds since unix epoch
+    /// number of milliseconds since unix epoch
     pub timestamp: Timestamp,
 
+    /// mutator set hash *prior* to updating mutator set with this transaction.
     pub mutator_set_hash: Digest,
 }