Safe Haskell	Safe-Inferred
Language	Haskell2010

Mini.Transformers.MaybeT

Contents

Description

Extend a monad with the ability to terminate a computation without a value

Synopsis

Type

newtype MaybeT m a Source #

A terminable transformer with inner monad m, return a

Constructors

Instances details

MonadTrans MaybeT Source #
Instance details Defined in Mini.Transformers.MaybeT Methods lift :: Monad m => m a -> MaybeT m a Source #
Monad m => Alternative (MaybeT m) Source #
Instance details Defined in Mini.Transformers.MaybeT Methods empty :: MaybeT m a # (<\|>) :: MaybeT m a -> MaybeT m a -> MaybeT m a # some :: MaybeT m a -> MaybeT m [a] # many :: MaybeT m a -> MaybeT m [a] #
Monad m => Applicative (MaybeT m) Source #
Instance details Defined in Mini.Transformers.MaybeT Methods pure :: a -> MaybeT m a # (<>) :: MaybeT m (a -> b) -> MaybeT m a -> MaybeT m b # liftA2 :: (a -> b -> c) -> MaybeT m a -> MaybeT m b -> MaybeT m c # (>) :: MaybeT m a -> MaybeT m b -> MaybeT m b # (<*) :: MaybeT m a -> MaybeT m b -> MaybeT m a #
Monad m => Functor (MaybeT m) Source #
Instance details Defined in Mini.Transformers.MaybeT Methods fmap :: (a -> b) -> MaybeT m a -> MaybeT m b # (<$) :: a -> MaybeT m b -> MaybeT m a #
Monad m => Monad (MaybeT m) Source #
Instance details Defined in Mini.Transformers.MaybeT Methods (>>=) :: MaybeT m a -> (a -> MaybeT m b) -> MaybeT m b # (>>) :: MaybeT m a -> MaybeT m b -> MaybeT m b # return :: a -> MaybeT m a #

Runner

Unwrap a MaybeT computation

Terminate the computation without a value

Run a computation and get its result