Safe Haskell	None
Language	Haskell2010

Bluefin.Eff

Contents

Synopsis

data Eff (es :: Effects) a
runPureEff :: (forall (es :: Effects). Eff es a) -> a
runEff :: (forall (e :: Effects) (es :: Effects). IOE e -> Eff (e :& es) a) -> IO a
withMonadIO :: forall (e :: Effects) (es :: Effects) r. e :> es => IOE e -> (forall (m :: Type -> Type). MonadIO m => m r) -> Eff es r
withMonadFail :: forall (e :: Effects) (es :: Effects) r. e :> es => Exception String e -> (forall (m :: Type -> Type). MonadFail m => m r) -> Eff es r
data Effects
class (es1 :: Effects) :> (es2 :: Effects)
type (:&) = 'Union

`Eff` monad

data Eff (es :: Effects) a Source #

Instances details

Applicative (Eff es)
Instance details Defined in Bluefin.Internal Methods pure :: a -> Eff es a # (<>) :: Eff es (a -> b) -> Eff es a -> Eff es b # liftA2 :: (a -> b -> c) -> Eff es a -> Eff es b -> Eff es c # (>) :: Eff es a -> Eff es b -> Eff es b # (<*) :: Eff es a -> Eff es b -> Eff es a #
Functor (Eff es)
Instance details Defined in Bluefin.Internal Methods fmap :: (a -> b) -> Eff es a -> Eff es b # (<$) :: a -> Eff es b -> Eff es a #
Monad (Eff es)
Instance details Defined in Bluefin.Internal Methods (>>=) :: Eff es a -> (a -> Eff es b) -> Eff es b # (>>) :: Eff es a -> Eff es b -> Eff es b # return :: a -> Eff es a #

Run an `Eff`

runPureEff :: (forall (es :: Effects). Eff es a) -> a Source #

Run an Eff that doesn't contain any unhandled effects.

Arguments

:: (forall (e :: Effects) (es :: Effects). IOE e -> Eff (e :& es) a)
-> IO a	͘

Run an Eff whose only unhandled effect is IO.

>>> runEff $ \io -> do
      effIO io (putStrLn "Hello world!")
Hello, world!

See Bluefin.Eff.IO for the most direct way of doing I/O in Bluefin. If you really want to use MonadIO you can use withMonadIO.

Arguments

:: forall (e :: Effects) (es :: Effects) r. e :> es
=> IOE e
-> (forall (m :: Type -> Type). MonadIO m => m r)	`MonadIO` operation
-> Eff es r	`MonadIO` operation run in `Eff`

Run MonadIO operations in Eff.

>>> runEff $ \io -> withMonadIO io $ liftIO $ do
      putStrLn "Hello world!"
Hello, world!

Arguments

:: forall (e :: Effects) (es :: Effects) r. e :> es
=> Exception String e	`Exception` to `throw` on `fail`
-> (forall (m :: Type -> Type). MonadFail m => m r)	`MonadFail` operation
-> Eff es r	`MonadFail` operation run in `Eff`

Run MonadFail operations in Eff.

>>> runPureEff $ try $ \e ->
      when (2 > 1) $
        withMonadFail e (fail "2 was bigger than 1")
Left "2 was bigger than 1"

class (es1 :: Effects) :> (es2 :: Effects) Source #

Effect subset constraint

Instances details

e :> e	A set of effects `e` is a subset of itself
Instance details Defined in Bluefin.Internal
e :> (e :& es)	`e` is a subset of a larger set `e :& es`
Instance details Defined in Bluefin.Internal
e :> es => e :> (x :& es)	If `e` is subset of `es` then `e` is a subset of a larger set, `x :& es`
Instance details Defined in Bluefin.Internal

type (:&) = 'Union infixr 9 Source #

type (:&) :: Effects -> Effects -> Effects

Union of effects