Control.Monad.Freer.Coroutine

An effect to compose functions with the ability to yield.

Using http://okmij.org/ftp/Haskell/extensible/Eff1.hs as a starting point.

Yield Control

data Yield a b c

A type representing a yielding of control.

Type variables have following meaning:

a

The current type.

b

The input to the continuation function.

c

The output of the continuation.

Constructors

Yield a (b -> c)

Instances

Functor (Yield a b)

Defined in Control.Monad.Freer.Coroutine

Methods

fmap :: (a0 -> b0) -> Yield a b a0 -> Yield a b b0

(<$) :: a0 -> Yield a b b0 -> Yield a b a0

yield :: Member (Yield a b) effs => a -> (b -> c) -> Eff effs c

Lifts a value and a function into the Coroutine effect.

Handle Yield Effect

data Status effs a b r

Represents status of a coroutine.

Constructors

Done r

Coroutine is done with a result value of type r.

Continue a (b -> Eff effs (Status effs a b r))

Reporting a value of the type a, and resuming with the value of type b, possibly ending with a value of type x.

runC :: Eff (Yield a b ': effs) r -> Eff effs (Status effs a b r)

Launch a coroutine and report its status.

interposeC :: Member (Yield a b) effs => Eff effs r -> Eff effs (Status effs a b r)

Launch a coroutine and report its status, without handling (removing) Yield from the typelist. This is useful for reducing nested coroutines.

replyC :: Yield a b c -> (c -> Eff effs (Status effs a b r)) -> Eff effs (Status effs a b r)

Reply to a coroutine effect by returning the Continue constructor.