postgresql-tx-0.2.0.0: A safe transaction monad for use with various PostgreSQL Haskell libraries.
Safe HaskellNone
LanguageHaskell2010

Database.PostgreSQL.Tx.HEnv

Synopsis

Documentation

data family HEnv (l :: [*]) infixr 2 Source #

Glorified hlist used to construct ad hoc tx runtime environments.

Instances

Instances details
Select a xs => TxEnv a (HEnv xs) Source #

TxEnv instance for HEnv; selects the first a in the HEnv and makes it available via the runtime environment.

Since: 0.2.0.0

Instance details

Defined in Database.PostgreSQL.Tx.HEnv

Methods

lookupTxEnv :: HEnv xs -> a Source #

data HEnv ('[] :: [Type]) Source # 
Instance details

Defined in Database.PostgreSQL.Tx.HEnv

data HEnv ('[] :: [Type]) = Nil
data HEnv (x ': xs) Source # 
Instance details

Defined in Database.PostgreSQL.Tx.HEnv

data HEnv (x ': xs) = x `Cons` (HEnv xs)

singleton :: a -> HEnv '[a] Source #

Construct an HEnv containing a single value.

Since: 0.2.0.0

fromTuple :: FromTuple i o => i -> HEnv o Source #

Construct an HEnv from the given tuple i. Instances support tuples of up to 16 elements.

Since: 0.2.0.0