Control.Monad.Abort

Error monad transformer and monad type classes for raising errors and recovering from them.

Documentation

class (Applicative μ, Monad μ) => MonadAbort e μ | μ -> e where

Class of monads that support raising of errors.

Minimal complete definition

abort

Methods

abort :: e -> μ α

Raise an error.

    abort e >>= rest = abort e

Instances

MonadAbort SomeException IO

Methods

abort :: SomeException -> IO α

MonadAbort e μ => MonadAbort e (ListT μ)

Methods

abort :: e -> ListT μ α

MonadAbort e μ => MonadAbort e (MaybeT μ)

Methods

abort :: e -> MaybeT μ α

(Functor μ, Monad μ) => MonadAbort e (ExceptT e μ)

Methods

abort :: e -> ExceptT e μ α

(Functor μ, Monad μ, Error e) => MonadAbort e (ErrorT e μ)

Methods

abort :: e -> ErrorT e μ α

(MonadAbort e μ, Monoid w) => MonadAbort e (WriterT w μ)

Methods

abort :: e -> WriterT w μ α

(MonadAbort e μ, Monoid w) => MonadAbort e (WriterT w μ)

Methods

abort :: e -> WriterT w μ α

MonadAbort e μ => MonadAbort e (StateT s μ)

Methods

abort :: e -> StateT s μ α

MonadAbort e μ => MonadAbort e (StateT s μ)

Methods

abort :: e -> StateT s μ α

MonadAbort e μ => MonadAbort e (IdentityT * μ)

Methods

abort :: e -> IdentityT * μ α

(Functor μ, Monad μ) => MonadAbort e (AbortT e μ)

Methods

abort :: e -> AbortT e μ α

MonadAbort e μ => MonadAbort e (ReaderT * r μ)

Methods

abort :: e -> ReaderT * r μ α

MonadAbort e μ => MonadAbort e (ContT * r μ)

Methods

abort :: e -> ContT * r μ α

(MonadAbort e μ, Monoid w) => MonadAbort e (RWST r w s μ)

Methods

abort :: e -> RWST r w s μ α

(MonadAbort e μ, Monoid w) => MonadAbort e (RWST r w s μ)

Methods

abort :: e -> RWST r w s μ α

class MonadAbort e μ => MonadRecover e μ | μ -> e where

Class of monads that support recovery from errors.

Minimal complete definition

recover | evaluate

Methods

recover :: μ α -> (e -> μ α) -> μ α

recover m h recovers from errors raised in computation m using the provided error handler h. The default implementation is

  evaluate m >>= either h return

evaluate :: μ α -> μ (Either e α)

evaluate m runs computation m, returning Left e if it raised an error e. The default implementation is

   recover (Right <$> m) (return . Left)

Instances

MonadRecover SomeException IO

Methods

recover :: IO α -> (SomeException -> IO α) -> IO α

evaluate :: IO α -> IO (Either SomeException α)

MonadRecover e μ => MonadRecover e (ListT μ)

Methods

recover :: ListT μ α -> (e -> ListT μ α) -> ListT μ α

evaluate :: ListT μ α -> ListT μ (Either e α)

MonadRecover e μ => MonadRecover e (MaybeT μ)

Methods

recover :: MaybeT μ α -> (e -> MaybeT μ α) -> MaybeT μ α

evaluate :: MaybeT μ α -> MaybeT μ (Either e α)

(Functor μ, Monad μ) => MonadRecover e (ExceptT e μ)

Methods

recover :: ExceptT e μ α -> (e -> ExceptT e μ α) -> ExceptT e μ α

evaluate :: ExceptT e μ α -> ExceptT e μ (Either e α)

(Functor μ, Monad μ, Error e) => MonadRecover e (ErrorT e μ)

Methods

recover :: ErrorT e μ α -> (e -> ErrorT e μ α) -> ErrorT e μ α

evaluate :: ErrorT e μ α -> ErrorT e μ (Either e α)

(MonadRecover e μ, Monoid w) => MonadRecover e (WriterT w μ)

Methods

recover :: WriterT w μ α -> (e -> WriterT w μ α) -> WriterT w μ α

evaluate :: WriterT w μ α -> WriterT w μ (Either e α)

(MonadRecover e μ, Monoid w) => MonadRecover e (WriterT w μ)

Methods

recover :: WriterT w μ α -> (e -> WriterT w μ α) -> WriterT w μ α

evaluate :: WriterT w μ α -> WriterT w μ (Either e α)

MonadRecover e μ => MonadRecover e (StateT s μ)

Methods

recover :: StateT s μ α -> (e -> StateT s μ α) -> StateT s μ α

evaluate :: StateT s μ α -> StateT s μ (Either e α)

MonadRecover e μ => MonadRecover e (StateT s μ)

Methods

recover :: StateT s μ α -> (e -> StateT s μ α) -> StateT s μ α

evaluate :: StateT s μ α -> StateT s μ (Either e α)

MonadRecover e μ => MonadRecover e (IdentityT * μ)

Methods

recover :: IdentityT * μ α -> (e -> IdentityT * μ α) -> IdentityT * μ α

evaluate :: IdentityT * μ α -> IdentityT * μ (Either e α)

(Functor μ, Monad μ) => MonadRecover e (AbortT e μ)

Methods

recover :: AbortT e μ α -> (e -> AbortT e μ α) -> AbortT e μ α

evaluate :: AbortT e μ α -> AbortT e μ (Either e α)

MonadRecover e μ => MonadRecover e (ReaderT * r μ)

Methods

recover :: ReaderT * r μ α -> (e -> ReaderT * r μ α) -> ReaderT * r μ α

evaluate :: ReaderT * r μ α -> ReaderT * r μ (Either e α)

(MonadRecover e μ, Monoid w) => MonadRecover e (RWST r w s μ)

Methods

recover :: RWST r w s μ α -> (e -> RWST r w s μ α) -> RWST r w s μ α

evaluate :: RWST r w s μ α -> RWST r w s μ (Either e α)

(MonadRecover e μ, Monoid w) => MonadRecover e (RWST r w s μ)

Methods

recover :: RWST r w s μ α -> (e -> RWST r w s μ α) -> RWST r w s μ α

evaluate :: RWST r w s μ α -> RWST r w s μ (Either e α)

onError :: MonadRecover e μ => μ α -> (e -> μ β) -> μ α

Run an action on error, without recovering from it.

onError_ :: MonadRecover e μ => μ α -> μ β -> μ α

Run an action on error (ignoring the error value), without recovering from it.

type Abort e α = AbortT e Identity α

An alias for AbortT over Identity.

runAbort :: Abort e α -> Either e α

runAbortT specialized for Abort.

newtype AbortT e μ α :: * -> (* -> *) -> * -> *

A monad transformer that extends monad μ with the ability to raise errors of type e and to recover from them.

Constructors

AbortT

Fields

• runAbortT :: μ (Either e α)

Instances

MonadBase η μ => MonadBase η (AbortT e μ)

Methods

liftBase :: η α -> AbortT e μ α

MonadBaseControl η μ => MonadBaseControl η (AbortT e μ)

Associated Types

type StM (AbortT e μ :: * -> *) a :: *

Methods

liftBaseWith :: (RunInBase (AbortT e μ) η -> η a) -> AbortT e μ a

restoreM :: StM (AbortT e μ) a -> AbortT e μ a

(Functor μ, Monad μ) => MonadRecover e (AbortT e μ)

Methods

recover :: AbortT e μ α -> (e -> AbortT e μ α) -> AbortT e μ α

evaluate :: AbortT e μ α -> AbortT e μ (Either e α)

(Functor μ, Monad μ) => MonadAbort e (AbortT e μ)

Methods

abort :: e -> AbortT e μ α

MonadFinish f μ => MonadFinish f (AbortT e μ)

Methods

finish :: f -> AbortT e μ α

MonadTrans (AbortT e)

Methods

lift :: Monad m => m a -> AbortT e m a

MonadTransControl (AbortT e)

Associated Types

type StT (AbortT e :: (* -> *) -> * -> *) a :: *

Methods

liftWith :: Monad m => (Run (AbortT e) -> m a) -> AbortT e m a

restoreT :: Monad m => m (StT (AbortT e) a) -> AbortT e m a

BindTrans (AbortT e)

Methods

liftB :: Bind b => b a -> AbortT e b a

Monad μ => Monad (AbortT e μ)

Methods

(>>=) :: AbortT e μ a -> (a -> AbortT e μ b) -> AbortT e μ b

(>>) :: AbortT e μ a -> AbortT e μ b -> AbortT e μ b

return :: a -> AbortT e μ a

fail :: String -> AbortT e μ a

Functor μ => Functor (AbortT e μ)

Methods

fmap :: (a -> b) -> AbortT e μ a -> AbortT e μ b

(<$) :: a -> AbortT e μ b -> AbortT e μ a

MonadFix μ => MonadFix (AbortT e μ)

Methods

mfix :: (a -> AbortT e μ a) -> AbortT e μ a

MonadFail μ => MonadFail (AbortT f μ)

Methods

fail :: String -> AbortT f μ a

(Functor μ, Monad μ) => Applicative (AbortT e μ)

Methods

pure :: a -> AbortT e μ a

(<*>) :: AbortT e μ (a -> b) -> AbortT e μ a -> AbortT e μ b

(*>) :: AbortT e μ a -> AbortT e μ b -> AbortT e μ b

(<*) :: AbortT e μ a -> AbortT e μ b -> AbortT e μ a

Foldable μ => Foldable (AbortT e μ)

Methods

fold :: Monoid m => AbortT e μ m -> m

foldMap :: Monoid m => (a -> m) -> AbortT e μ a -> m

foldr :: (a -> b -> b) -> b -> AbortT e μ a -> b

foldr' :: (a -> b -> b) -> b -> AbortT e μ a -> b

foldl :: (b -> a -> b) -> b -> AbortT e μ a -> b

foldl' :: (b -> a -> b) -> b -> AbortT e μ a -> b

foldr1 :: (a -> a -> a) -> AbortT e μ a -> a

foldl1 :: (a -> a -> a) -> AbortT e μ a -> a

toList :: AbortT e μ a -> [a]

null :: AbortT e μ a -> Bool

length :: AbortT e μ a -> Int

elem :: Eq a => a -> AbortT e μ a -> Bool

maximum :: Ord a => AbortT e μ a -> a

minimum :: Ord a => AbortT e μ a -> a

sum :: Num a => AbortT e μ a -> a

product :: Num a => AbortT e μ a -> a

Traversable μ => Traversable (AbortT e μ)

Methods

traverse :: Applicative f => (a -> f b) -> AbortT e μ a -> f (AbortT e μ b)

sequenceA :: Applicative f => AbortT e μ (f a) -> f (AbortT e μ a)

mapM :: Monad m => (a -> m b) -> AbortT e μ a -> m (AbortT e μ b)

sequence :: Monad m => AbortT e μ (m a) -> m (AbortT e μ a)

(Eq f, Eq1 μ) => Eq1 (AbortT f μ)

Methods

liftEq :: (a -> b -> Bool) -> AbortT f μ a -> AbortT f μ b -> Bool

(Ord f, Ord1 μ) => Ord1 (AbortT f μ)

Methods

liftCompare :: (a -> b -> Ordering) -> AbortT f μ a -> AbortT f μ b -> Ordering

(Read f, Read1 μ) => Read1 (AbortT f μ)

Methods

liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (AbortT f μ a)

liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [AbortT f μ a]

(Show f, Show1 μ) => Show1 (AbortT f μ)

Methods

liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> AbortT f μ a -> ShowS

liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [AbortT f μ a] -> ShowS

MonadZip μ => MonadZip (AbortT f μ)

Methods

mzip :: AbortT f μ a -> AbortT f μ b -> AbortT f μ (a, b)

mzipWith :: (a -> b -> c) -> AbortT f μ a -> AbortT f μ b -> AbortT f μ c

munzip :: AbortT f μ (a, b) -> (AbortT f μ a, AbortT f μ b)

MonadIO μ => MonadIO (AbortT e μ)

Methods

liftIO :: IO a -> AbortT e μ a

Pointed μ => Pointed (AbortT e μ)

Methods

point :: a -> AbortT e μ a

(Functor μ, Monad μ) => Apply (AbortT e μ)

Methods

(<.>) :: AbortT e μ (a -> b) -> AbortT e μ a -> AbortT e μ b

(.>) :: AbortT e μ a -> AbortT e μ b -> AbortT e μ b

(<.) :: AbortT e μ a -> AbortT e μ b -> AbortT e μ a

(Functor μ, Monad μ) => Bind (AbortT e μ)

Methods

(>>-) :: AbortT e μ a -> (a -> AbortT e μ b) -> AbortT e μ b

join :: AbortT e μ (AbortT e μ a) -> AbortT e μ a

(Eq f, Eq1 μ, Eq α) => Eq (AbortT f μ α)

Methods

(==) :: AbortT f μ α -> AbortT f μ α -> Bool

(/=) :: AbortT f μ α -> AbortT f μ α -> Bool

(Ord f, Ord1 μ, Ord α) => Ord (AbortT f μ α)

Methods

compare :: AbortT f μ α -> AbortT f μ α -> Ordering

(<) :: AbortT f μ α -> AbortT f μ α -> Bool

(<=) :: AbortT f μ α -> AbortT f μ α -> Bool

(>) :: AbortT f μ α -> AbortT f μ α -> Bool

(>=) :: AbortT f μ α -> AbortT f μ α -> Bool

max :: AbortT f μ α -> AbortT f μ α -> AbortT f μ α

min :: AbortT f μ α -> AbortT f μ α -> AbortT f μ α

(Read f, Read1 μ, Read α) => Read (AbortT f μ α)

Methods

readsPrec :: Int -> ReadS (AbortT f μ α)

readList :: ReadS [AbortT f μ α]

readPrec :: ReadPrec (AbortT f μ α)

readListPrec :: ReadPrec [AbortT f μ α]

(Show f, Show1 μ, Show α) => Show (AbortT f μ α)

Methods

showsPrec :: Int -> AbortT f μ α -> ShowS

show :: AbortT f μ α -> String

showList :: [AbortT f μ α] -> ShowS

type StT (AbortT e) α

type StT (AbortT e) α = Either e α

type StM (AbortT e μ) α

type StM (AbortT e μ) α = ComposeSt (AbortT e) μ α

module Control.Monad

module Control.Monad.Fix

module Control.Monad.Trans