Safe Haskell	None
Language	Haskell2010

Database.PostgreSQL.Tx.Squeal.Internal

Contents

Disclaimer
- Internals

Synopsis

newtype SquealConnection = UnsafeSquealConnection {
- unsafeGetLibPQConnection :: IO Connection
}
newtype SquealTxM' (db :: SchemasType) r a = SquealTxM {
- fromSquealTxM :: TxM r a
}
type SquealTxM (db :: SchemasType) a = forall r. SquealEnv r => SquealTxM' db r a
type SquealM a = forall r. SquealEnv r => TxM r a
type SquealEnv r = TxEnv SquealConnection r :: Constraint
mkSquealConnection :: Connection -> SquealConnection
fromSquealException :: SquealException -> TxException
unsafeSquealIOTxM :: PQ db db IO a -> SquealTxM db a
unsafeSquealIOTxM1 :: (x1 -> PQ db db IO a) -> x1 -> SquealTxM db a
unsafeSquealIOTxM2 :: (x1 -> x2 -> PQ db db IO a) -> x1 -> x2 -> SquealTxM db a
unsafeSquealIOTxM3 :: (x1 -> x2 -> x3 -> PQ db db IO a) -> x1 -> x2 -> x3 -> SquealTxM db a
unsafeRunSquealTransaction :: forall r a. SquealEnv r => (forall db. PQ db db IO a -> PQ db db IO a) -> r -> TxM r a -> IO a
transactionallyRetry' :: (MonadUnliftIO m, MonadPQ db m, Exception e) => TransactionMode -> (e -> Bool) -> m a -> m a

Disclaimer

Changes to this module will not be reflected in the library's version updates.

Internals

newtype SquealConnection Source #

Used in the SquealEnv to specify the Connection to use. Should produce the same Connection if called multiple times in the same transaction. Usually you will want to use mkSquealConnection to get one.

Since: 0.2.0.0

Constructors

UnsafeSquealConnection
Fields unsafeGetLibPQConnection :: IO Connection

newtype SquealTxM' (db :: SchemasType) r a Source #

A newtype wrapper around TxM which includes the squeal SchemasType parameter db. This is used only as type information. You can easily convert TxM to and from SquealTxM' by using the SquealTxM' constructor and fromSquealTxM function, respectively.

In practice, you will likely prefer to use the SquealTxM type alias as it includes the SquealEnv constraint on r.

Since: 0.2.0.0

Constructors

SquealTxM
Fields fromSquealTxM :: TxM r a Convert a `SquealTxM'` to a `TxM`. Since: 0.2.0.0

Instances

Instances details

Monad (SquealTxM' db r) Source #
Instance details Defined in Database.PostgreSQL.Tx.Squeal.Internal Methods (>>=) :: SquealTxM' db r a -> (a -> SquealTxM' db r b) -> SquealTxM' db r b # (>>) :: SquealTxM' db r a -> SquealTxM' db r b -> SquealTxM' db r b # return :: a -> SquealTxM' db r a #
Functor (SquealTxM' db r) Source #
Instance details Defined in Database.PostgreSQL.Tx.Squeal.Internal Methods fmap :: (a -> b) -> SquealTxM' db r a -> SquealTxM' db r b # (<$) :: a -> SquealTxM' db r b -> SquealTxM' db r a #
Applicative (SquealTxM' db r) Source #
Instance details Defined in Database.PostgreSQL.Tx.Squeal.Internal Methods pure :: a -> SquealTxM' db r a # (<>) :: SquealTxM' db r (a -> b) -> SquealTxM' db r a -> SquealTxM' db r b # liftA2 :: (a -> b -> c) -> SquealTxM' db r a -> SquealTxM' db r b -> SquealTxM' db r c # (>) :: SquealTxM' db r a -> SquealTxM' db r b -> SquealTxM' db r b # (<*) :: SquealTxM' db r a -> SquealTxM' db r b -> SquealTxM' db r a #
(TypeError ('Text "MonadIO is banned in SquealTxM'; use 'SquealTxM . unsafeRunIOInTxM' if you are sure this is safe IO") :: Constraint) => MonadIO (SquealTxM' db r) Source #	The `SquealTxM'` monad discourages performing arbitrary `IO` within a transaction, so this instance generates a type error when client code tries to call `liftIO`. Note that we specialize this instance for `SquealTxM'` rather than derive it via newtype so we can provide a better error message. Since: 0.2.0.0
Instance details Defined in Database.PostgreSQL.Tx.Squeal.Internal Methods liftIO :: IO a -> SquealTxM' db r a #

type SquealTxM (db :: SchemasType) a = forall r. SquealEnv r => SquealTxM' db r a Source #

Alias for SquealTxM' but has the SquealEnv constraint applied to r.

Since: 0.2.0.0

type SquealM a = forall r. SquealEnv r => TxM r a Source #

Monad type alias for running squeal-postgresql via postgresql-tx.

Since: 0.2.0.0

type SquealEnv r = TxEnv SquealConnection r :: Constraint Source #

Runtime environment needed to run squeal-postgresql via postgresql-tx.

Since: 0.2.0.0

mkSquealConnection :: Connection -> SquealConnection Source #

Construct a SquealConnection from a Connection.

Since: 0.2.0.0

fromSquealException :: SquealException -> TxException Source #

unsafeSquealIOTxM :: PQ db db IO a -> SquealTxM db a Source #

unsafeSquealIOTxM1 :: (x1 -> PQ db db IO a) -> x1 -> SquealTxM db a Source #

unsafeSquealIOTxM2 :: (x1 -> x2 -> PQ db db IO a) -> x1 -> x2 -> SquealTxM db a Source #

unsafeSquealIOTxM3 :: (x1 -> x2 -> x3 -> PQ db db IO a) -> x1 -> x2 -> x3 -> SquealTxM db a Source #

unsafeRunSquealTransaction :: forall r a. SquealEnv r => (forall db. PQ db db IO a -> PQ db db IO a) -> r -> TxM r a -> IO a Source #

transactionallyRetry' :: (MonadUnliftIO m, MonadPQ db m, Exception e) => TransactionMode -> (e -> Bool) -> m a -> m a Source #

A variant of transactionallyRetry which takes a predicate for determining when to retry instead of only doing so on serialization_failure.