Control.Eff.Choose

Nondeterministic choice effect

Documentation

newtype Choose a

Non-determinism (choice)

choose lst non-deterministically chooses one value from the lst choose [] thus corresponds to failure Unlike Reader, Choose is not a GADT because the type of values returned in response to a (Choose a) request is just a, without any constraints.

Constructors

Choose [a]

Instances

(MonadBase m m, SetMember (* -> *) (Lift *) (Lift * m) r, MonadBaseControl m (Eff r)) => MonadBaseControl m (Eff ((:) (* -> *) Choose r))

Associated Types

type StM (Eff (((* -> *) ': Choose) r) :: * -> *) a :: *

Methods

liftBaseWith :: (RunInBase (Eff (((* -> *) ': Choose) r)) m -> m a) -> Eff (((* -> *) ': Choose) r) a

restoreM :: StM (Eff (((* -> *) ': Choose) r)) a -> Eff (((* -> *) ': Choose) r) a

type StM (Eff ((:) (* -> *) Choose r)) a

type StM (Eff ((:) (* -> *) Choose r)) a = StM (Eff r) [a]

choose :: Member Choose r => [a] -> Eff r a

choose lst non-deterministically chooses one value from the lst choose [] thus corresponds to failure

makeChoice :: forall a r. Eff (Choose ': r) a -> Eff r [a]

Run a nondeterministic effect, returning all values.

mzero' :: Member Choose r => Eff r a

MonadPlus-like operators are expressible via choose

mplus' :: Member Choose r => Eff r a -> Eff r a -> Eff r a

MonadPlus-like operators are expressible via choose

Orphan instances

Member Choose r => Alternative (Eff r)

MonadPlus-like operators are expressible via choose

Methods

empty :: Eff r a

(<|>) :: Eff r a -> Eff r a -> Eff r a

some :: Eff r a -> Eff r [a]

many :: Eff r a -> Eff r [a]

Member Choose r => MonadPlus (Eff r)

Methods

mzero :: Eff r a

mplus :: Eff r a -> Eff r a -> Eff r a