Database.PostgreSQL.Tx

Documentation

data TxM a

Instances

Monad TxM

Defined in Database.PostgreSQL.Tx

Methods

(>>=) :: TxM a -> (a -> TxM b) -> TxM b

(>>) :: TxM a -> TxM b -> TxM b

return :: a -> TxM a

fail :: String -> TxM a

Functor TxM

Defined in Database.PostgreSQL.Tx

Methods

fmap :: (a -> b) -> TxM a -> TxM b

(<$) :: a -> TxM b -> TxM a

Applicative TxM

Defined in Database.PostgreSQL.Tx

Methods

pure :: a -> TxM a

(<*>) :: TxM (a -> b) -> TxM a -> TxM b

liftA2 :: (a -> b -> c) -> TxM a -> TxM b -> TxM c

(*>) :: TxM a -> TxM b -> TxM b

(<*) :: TxM a -> TxM b -> TxM a

(TypeError (Text "MonadIO is banned in TxM; use 'unsafeRunIOInTxM' if you are sure this is safe IO") :: Constraint) => MonadIO TxM

Defined in Database.PostgreSQL.Tx

Methods

liftIO :: IO a -> TxM a

UnsafeTx IO TxM

Defined in Database.PostgreSQL.Tx

Methods

unsafeIOTx :: IO a -> TxM a

Tx (ReaderT r TxM)

Defined in Database.PostgreSQL.Tx

Associated Types

type TxEnv (ReaderT r TxM) :: Type

Methods

tx :: TxEnv (ReaderT r TxM) -> ReaderT r TxM a -> TxM a

type TxEnv (ReaderT r TxM)

Defined in Database.PostgreSQL.Tx

type TxEnv (ReaderT r TxM) = r

unsafeRunIOInTxM :: IO a -> TxM a

class Tx (f :: * -> *) where

Type class for converting an f to TxM given a TxEnv.

Associated Types

type TxEnv f :: *

The runtime environment needed to convert f to TxM.

Methods

tx :: TxEnv f -> f a -> TxM a

Converts an f to a TxM.

Instances

Tx (ReaderT r TxM)

Defined in Database.PostgreSQL.Tx

Associated Types

type TxEnv (ReaderT r TxM) :: Type

Methods

tx :: TxEnv (ReaderT r TxM) -> ReaderT r TxM a -> TxM a

class UnsafeTx (io :: * -> *) (t :: * -> *) | t -> io where

Promote an unsafe io action to a safe t transaction (will be some form of TxM).

Methods

unsafeIOTx :: io a -> t a

Converts an io action to a t, which will be some form of TxM.

Instances

UnsafeTx IO TxM

Defined in Database.PostgreSQL.Tx

Methods

unsafeIOTx :: IO a -> TxM a

UnsafeTx io t => UnsafeTx (ReaderT r io) (ReaderT r t)

Defined in Database.PostgreSQL.Tx

Methods

unsafeIOTx :: ReaderT r io a -> ReaderT r t a

unsafeReaderIOTx :: UnsafeTx (ReaderT r io) (ReaderT r t) => (r -> io a) -> ReaderT r t a

Promotes an unsafe io function to some ReaderT over TxM.