Control.Effects.List

Documentation

data NonDeterministic

Instances

Monad m => MonadEffect1 NonDeterministic (ListT m)

Methods

effect1 :: EffectCon1 NonDeterministic a => proxy NonDeterministic -> EffectMsg1 NonDeterministic a -> ListT m (EffectRes1 NonDeterministic a)

type EffectRes1 NonDeterministic

type EffectRes1 NonDeterministic = Identity

type EffectMsg1 NonDeterministic

type EffectMsg1 NonDeterministic = []

type EffectCon1 NonDeterministic a

type EffectCon1 NonDeterministic a = ()

choose :: MonadEffect1 NonDeterministic m => [a] -> m a

Runs the rest of the computation for every value in the list

deadEnd :: MonadEffect1 NonDeterministic m => m a

Signals that this branch of execution failed to produce a result.

evaluateToList :: Monad m => ListT m a -> m [a]

Execute all the effects and collect the result in a list. Note that this forces all the results, no matter which elements of the result list you end up actually using. For lazyer behavior use the other handlers.

traverseAllResults :: Monad m => (a -> m ()) -> ListT m a -> m ()

Given a function, apply it to all the results.

foldAllResults :: Monad m => (r -> a -> m r) -> r -> ListT m a -> m r

Given a folding function, fold over every result. If you want to terminate eary, use the foldWithEarlyTermination instead.

foldWithEarlyTermination :: Monad m => (r -> a -> m (Maybe r)) -> r -> ListT m a -> m r

Same as foldAllResults but the folding function has the ability to terminate eary by returning Nothing.

evaluateNResults :: Monad m => Int -> ListT m a -> m [a]

Executes only the effects needed to produce the first n results.

evaluateOneResult :: Monad m => ListT m a -> m (Maybe a)

Executes only the effects needed to produce a single result.

module ListT