Safe Haskell	Safe-Inferred
Language	Haskell2010

Database.Persist.Monad.Internal.SqlTransaction

Synopsis

newtype SqlTransaction m a = UnsafeSqlTransaction {
- unSqlTransaction :: ReaderT SqlTransactionEnv m a
}
data SqlTransactionEnv = SqlTransactionEnv {
- sqlBackend :: SqlBackend
- ignoreCatch :: SomeException -> Bool
}
runSqlTransaction :: MonadUnliftIO m => SqlTransactionEnv -> SqlTransaction m a -> m a
catchSqlTransaction :: (MonadUnliftIO m, Exception e) => SqlTransaction m a -> (e -> SqlTransaction m a) -> SqlTransaction m a

Documentation

newtype SqlTransaction m a Source #

The monad that tracks transaction state.

Conceptually equivalent to SqlPersistT, but restricts IO operations, for two reasons:

Forking a thread that uses the same SqlBackend as the current thread causes Bad Things to happen.
Transactions may need to be retried, in which case IO operations in a transaction are required to be rerunnable.

You shouldn't need to explicitly use this type; your functions should only declare the MonadSqlQuery constraint.

Constructors

UnsafeSqlTransaction
Fields unSqlTransaction :: ReaderT SqlTransactionEnv m a

Instances

Instances details

MonadRerunnableTrans SqlTransaction Source #
Instance details Defined in Database.Persist.Monad.Internal.SqlTransaction Methods rerunnableLift :: Monad m => m a -> SqlTransaction m a Source #
MonadFix m => MonadFix (SqlTransaction m) Source #
Instance details Defined in Database.Persist.Monad.Internal.SqlTransaction Methods mfix :: (a -> SqlTransaction m a) -> SqlTransaction m a #
(TypeError ('Text "Cannot run arbitrary IO actions within a transaction. If the IO action is rerunnable, use rerunnableIO") :: Constraint, Monad m) => MonadIO (SqlTransaction m) Source #
Instance details Defined in Database.Persist.Monad.Internal.SqlTransaction Methods liftIO :: IO a -> SqlTransaction m a #
Applicative m => Applicative (SqlTransaction m) Source #
Instance details Defined in Database.Persist.Monad.Internal.SqlTransaction Methods pure :: a -> SqlTransaction m a # (<>) :: SqlTransaction m (a -> b) -> SqlTransaction m a -> SqlTransaction m b # liftA2 :: (a -> b -> c) -> SqlTransaction m a -> SqlTransaction m b -> SqlTransaction m c # (>) :: SqlTransaction m a -> SqlTransaction m b -> SqlTransaction m b # (<*) :: SqlTransaction m a -> SqlTransaction m b -> SqlTransaction m a #
Functor m => Functor (SqlTransaction m) Source #
Instance details Defined in Database.Persist.Monad.Internal.SqlTransaction Methods fmap :: (a -> b) -> SqlTransaction m a -> SqlTransaction m b # (<$) :: a -> SqlTransaction m b -> SqlTransaction m a #
Monad m => Monad (SqlTransaction m) Source #
Instance details Defined in Database.Persist.Monad.Internal.SqlTransaction Methods (>>=) :: SqlTransaction m a -> (a -> SqlTransaction m b) -> SqlTransaction m b # (>>) :: SqlTransaction m a -> SqlTransaction m b -> SqlTransaction m b # return :: a -> SqlTransaction m a #
MonadRerunnableIO m => MonadRerunnableIO (SqlTransaction m) Source #
Instance details Defined in Database.Persist.Monad.Internal.SqlTransaction Methods rerunnableIO :: IO a -> SqlTransaction m a Source #
(MonadSqlQuery m, MonadUnliftIO m) => MonadSqlQuery (SqlTransaction m) Source #
Instance details Defined in Database.Persist.Monad.Internal.SqlTransaction Associated Types type TransactionM (SqlTransaction m) :: Type -> Type Source # Methods runQueryRep :: Typeable record => SqlQueryRep record a -> SqlTransaction m a Source # withTransaction :: TransactionM (SqlTransaction m) a -> SqlTransaction m a Source #
type TransactionM (SqlTransaction m) Source #
Instance details Defined in Database.Persist.Monad.Internal.SqlTransaction type TransactionM (SqlTransaction m) = TransactionM m

data SqlTransactionEnv Source #

Constructors

SqlTransactionEnv
Fields sqlBackend :: SqlBackend ignoreCatch :: SomeException -> Bool

runSqlTransaction :: MonadUnliftIO m => SqlTransactionEnv -> SqlTransaction m a -> m a Source #

catchSqlTransaction :: (MonadUnliftIO m, Exception e) => SqlTransaction m a -> (e -> SqlTransaction m a) -> SqlTransaction m a Source #

Like normal catch, except ignores errors specified by ignoreCatch.