Add field persistence for Slot primitive type.

lib/wallet/src/Cardano/Wallet/DB/Sqlite/Types.hs

@@ -52,7 +52,9 @@ import Cardano.Wallet.Primitive.Types
     ( EpochNo (..)
     , FeePolicy
     , PoolMetadataSource (..)
+    , Slot
     , WalletId (..)
+    , WithOrigin (..)
     , isValidEpochNo
     , unsafeEpochNo
     , unsafeToPMS
@@ -139,6 +141,8 @@ import qualified Cardano.Wallet.Primitive.Types.Coin as Coin
 import qualified Data.Aeson as Aeson
 import qualified Data.ByteString as BS
 import qualified Data.ByteString.Lazy as BL
+import Data.Int
+    ( Int64 )
 import qualified Data.Text as T
 import qualified Data.Text.Encoding as T
 
@@ -748,3 +752,16 @@ instance PersistField BlockHeight where
 
 instance PersistFieldSql BlockHeight where
     sqlType _ = sqlType (Proxy @Word32)
+
+instance PersistField Slot where
+    toPersistValue Origin = toPersistValue ((-1) :: Int64)
+    toPersistValue (At s) = toPersistValue (fromIntegral $ unSlotNo s :: Int64)
+    fromPersistValue v = case fromPersistValue v of
+        Right (PersistInt64 x)
+            | x < (-1) -> Left "Slot must be positive or -1"
+            | x == (-1) -> Right Origin
+            | otherwise -> Right . At . SlotNo . fromIntegral $ x
+        _ -> Left "Slot must be an Int64"
+
+instance PersistFieldSql Slot where
+    sqlType _ = sqlType (Proxy @Int64)