valiant-fused-effects

fused-effects adapter for valiant.

Provides a Valiant effect, a ValiantPoolC carrier (built on ReaderC Pool), and Has (Reader Pool) sig m-constrained smart constructors.

Quick start

import Control.Carrier.Lift (runM)
import Valiant (newPool, defaultPoolConfig, poolConnString)
import Valiant.FusedEffects

myApp :: (Has (Reader Pool) sig m, MonadIO m) => m [User]
myApp = do
  users <- fetchAllF listUsers ()
  pure users

main :: IO ()
main = do
  pool <- newPool defaultPoolConfig { poolConnString = "postgres://..." }
  users <- runM . runValiantPool pool $ myApp
  print users

What you get

• Effect: data Valiant
• Carrier: type ValiantPoolC m = ReaderC Pool m with runValiantPool :: Pool -> ValiantPoolC m a -> m a
• Query operations: fetchOneF, fetchAllF, fetchScalarF, fetchOneOrThrowF, fetchExistsF
• Command operations: executeF, executeReturningF, executeBatchF
• Transactions: withTransactionF
• Raw access: withConnectionF

See the valiant tutorial for Statement definitions and the valiant prepare workflow.