Copyright	(c) Eamon Olive 2020 (c) Louis Hyde 2020
License	AGPL-3
Maintainer	ejolive97@gmail.com
Stability	experimental
Safe Haskell	Safe
Language	Haskell2010

Control.Monad.Trans.Choice.Covariant

Description

Synopsis

data ChoiceT f m a
runChoiceT :: Monad m => (forall x. f x -> m x) -> ChoiceT f m a -> m a
mapChoiceT :: (forall x. m x -> n x) -> ChoiceT f m a -> ChoiceT f n a
runBacktrackableChoiceT :: forall f m a. Monad m => (forall x. f x -> m (Maybe x)) -> ChoiceT f m a -> m (Maybe a)

Documentation

data ChoiceT f m a Source #

Instances

MonadRWS r w s m => MonadRWS r w s (ChoiceT f m) Source #
Instance details Defined in Control.Monad.Trans.Choice.Covariant
MonadWriter w m => MonadWriter w (ChoiceT f m) Source #
Instance details Defined in Control.Monad.Trans.Choice.Covariant Methods writer :: (a, w) -> ChoiceT f m a # tell :: w -> ChoiceT f m () # listen :: ChoiceT f m a -> ChoiceT f m (a, w) # pass :: ChoiceT f m (a, w -> w) -> ChoiceT f m a #
MonadState s m => MonadState s (ChoiceT f m) Source #
Instance details Defined in Control.Monad.Trans.Choice.Covariant Methods get :: ChoiceT f m s # put :: s -> ChoiceT f m () # state :: (s -> (a, s)) -> ChoiceT f m a #
MonadReader r m => MonadReader r (ChoiceT f m) Source #
Instance details Defined in Control.Monad.Trans.Choice.Covariant Methods ask :: ChoiceT f m r # local :: (r -> r) -> ChoiceT f m a -> ChoiceT f m a # reader :: (r -> a) -> ChoiceT f m a #
MonadChoice f (ChoiceT f m) Source #
Instance details Defined in Control.Monad.Trans.Choice.Covariant Methods choose :: f a -> ChoiceT f m a Source #
MonadTrans (ChoiceT f) Source #
Instance details Defined in Control.Monad.Trans.Choice.Covariant Methods lift :: Monad m => m a -> ChoiceT f m a #
Monad (ChoiceT f m) Source #
Instance details Defined in Control.Monad.Trans.Choice.Covariant Methods (>>=) :: ChoiceT f m a -> (a -> ChoiceT f m b) -> ChoiceT f m b # (>>) :: ChoiceT f m a -> ChoiceT f m b -> ChoiceT f m b # return :: a -> ChoiceT f m a # fail :: String -> ChoiceT f m a #
Functor (ChoiceT f m) Source #
Instance details Defined in Control.Monad.Trans.Choice.Covariant Methods fmap :: (a -> b) -> ChoiceT f m a -> ChoiceT f m b # (<$) :: a -> ChoiceT f m b -> ChoiceT f m a #
Applicative (ChoiceT f m) Source #
Instance details Defined in Control.Monad.Trans.Choice.Covariant Methods pure :: a -> ChoiceT f m a # (<>) :: ChoiceT f m (a -> b) -> ChoiceT f m a -> ChoiceT f m b # liftA2 :: (a -> b -> c) -> ChoiceT f m a -> ChoiceT f m b -> ChoiceT f m c # (>) :: ChoiceT f m a -> ChoiceT f m b -> ChoiceT f m b # (<*) :: ChoiceT f m a -> ChoiceT f m b -> ChoiceT f m a #
MonadIO m => MonadIO (ChoiceT f m) Source #
Instance details Defined in Control.Monad.Trans.Choice.Covariant Methods liftIO :: IO a -> ChoiceT f m a #

runChoiceT :: Monad m => (forall x. f x -> m x) -> ChoiceT f m a -> m a Source #

mapChoiceT :: (forall x. m x -> n x) -> ChoiceT f m a -> ChoiceT f n a Source #

runBacktrackableChoiceT Source #

Arguments

:: Monad m
=> (forall x. f x -> m (Maybe x))	The selection function. If the result of the outputted computation is `Nothing` then `runBacktrackableChoiceT` will backtrack to the previous choice. Otherwise, the result is a `Just` then it will proceed like `runChoiceT`.
-> ChoiceT f m a	The choice structure to run
-> m (Maybe a)	The resulting computation. If the selection function backtracks on the first choice the result of the computation will be `Nothing`.

A variant of runChoiceT that allows for the selection function to output Nothing to represent the desire to potentially select a different option for the previous choice.