Rename TxHash to Hash and move into its own module

Reason: we'll need hashes for more than just transactions

abc/hash.nim

@@ -0,0 +1,16 @@
+import std/hashes except Hash
+import pkg/nimcrypto
+
+type
+  Hash* = distinct MDigest[256]
+
+func `==`*(a, b: Hash): bool {.borrow.}
+
+func hash*(bytes: openArray[byte]): Hash =
+  Hash(sha256.digest(bytes))
+
+func toBytes*(hash: Hash): array[32, byte] =
+  MDigest[256](hash).data
+
+func hash*(hash: Hash): hashes.Hash =
+  hashes.hash(hash.toBytes)

abc/transactions.nim

@@ -5,9 +5,11 @@ import pkg/stint
 import pkg/questionable
 import ./keys
 import ./helpers
+import ./hash
 
 export stint
 export keys
+export hash
 
 type
   Transaction* = object
@@ -16,14 +18,11 @@ type
     validator: PublicKey
     signature: Signature
   TxInput* = tuple
-    txHash: TxHash
+    transaction: Hash
     owner: PublicKey
   TxOutput* = tuple
     owner: PublicKey
     value: UInt256
-  TxHash* = distinct MDigest[256]
-
-func `==`*(a, b: TxHash): bool {.borrow.}
 
 func init*(_: type Transaction,
            inputs: openArray[TxInput],
@@ -57,9 +56,6 @@ func validator*(transaction: Transaction): PublicKey =
 func add*(transaction: var Transaction, signature: Signature) =
   transaction.signature = aggregate(transaction.signature, signature)
 
-func toBytes*(hash: TxHash): array[32, byte] =
-  MDigest[256](hash).data
-
 func toBytes*(transaction: Transaction): seq[byte] =
   result.add(transaction.inputs.len.uint8)
   for (txHash, owner) in transaction.inputs:
@@ -71,8 +67,8 @@ func toBytes*(transaction: Transaction): seq[byte] =
     result.add(value.toBytes)
   result.add(transaction.validator.toBytes)
 
-func hash*(transaction: Transaction): TxHash =
-  TxHash(sha256.digest(transaction.toBytes))
+func hash*(transaction: Transaction): Hash =
+  hash(transaction.toBytes)
 
 func sign*(key: PrivateKey, transaction: var Transaction) =
   transaction.add(key.sign(transaction.hash.toBytes))

abc/txstore.nim

@@ -1,17 +1,13 @@
 import std/tables
-import std/hashes
 import ./transactions
 
 type
   TxStore* = object
-    genesis: TxHash
-    transactions: Table[TxHash, Transaction]
+    genesis: Hash
+    transactions: Table[Hash, Transaction]
 
 export transactions
 
-func hash(h: TxHash): Hash =
-  h.toBytes.hash
-
 func add*(store: var TxStore, transactions: varargs[Transaction]) =
   for transaction in transactions:
     store.transactions[transaction.hash] = transaction
@@ -20,11 +16,11 @@ func init*(_: type TxStore, genesis: Transaction): TxStore =
   result.genesis = genesis.hash
   result.add(genesis)
 
-func genesis*(store: TxStore): TxHash =
+func genesis*(store: TxStore): Hash =
   store.genesis
 
-func hasTx*(store: TxStore, hash: TxHash): bool =
+func hasTx*(store: TxStore, hash: Hash): bool =
   store.transactions.hasKey(hash)
 
-func `[]`*(store: TxStore, hash: TxHash): Transaction =
+func `[]`*(store: TxStore, hash: Hash): Transaction =
   store.transactions[hash]

abc/txvalidation.nim

@@ -13,14 +13,14 @@ func checkValue(store: TxStore, transaction: Transaction): bool =
 
   valueIn == valueOut
 
-func hasValidTx*(store: TxStore, hash: TxHash): bool =
-  if hash == store.genesis:
+func hasValidTx*(store: TxStore, txHash: Hash): bool =
+  if txHash == store.genesis:
     return true
 
-  if not store.hasTx(hash):
+  if not store.hasTx(txHash):
     return false
 
-  let transaction = store[hash]
+  let transaction = store[txHash]
 
   if not transaction.hasValidSignature:
     return false