Control.Eff.Operational

Operational Monad (https://wiki.haskell.org/Operational) implemented with extensible effects.

Documentation

data Program instr v

Lift values to an effect. You can think this is a generalization of Lift.

Constructors

forall a . Program (instr a) (a -> v)

Instances

Functor (Program instr)

Typeable ((* -> *) -> * -> *) Program

singleton :: (Typeable instr, Member (Program instr) r) => instr a -> Eff r a

Lift a value to a monad.

runProgram :: Typeable f => (forall x. f x -> Eff r x) -> Eff (Program f :> r) a -> Eff r a

Convert values using given interpreter to effects.

Usage

See Example for an example of defining data using GADTs and implementing interpreters from the data to effects.

To use the interpreter, see below or consult the tests.

main :: IO ()
main = do
    putStrLn . fst . run . runMonoidWriter . evalState ["foo","bar"] $ runProgram adventPure prog
    runLift $ runProgram adventIO prog