Safe Haskell	Safe
Language	Haskell98

Control.Proxy.Trans.Either

Contents

EitherP
Either operations
Symmetric monad

Description

This module provides the proxy transformer equivalent of EitherT.

Synopsis

EitherP

newtype EitherP e p a' a b' b m r Source #

The Either proxy transformer

Constructors

EitherP
Fields runEitherP :: p a' a b' b m (Either e r)

Instances

ProxyTrans (EitherP e) Source #
Methods liftP :: (Monad (p b c d e m), Channel p) => p b c d e m r -> EitherP e p b c d e m r Source # mapP :: (Monad (p b c d e m), Channel p) => (a -> p b c d e m r) -> a -> EitherP e p b c d e m r Source #
Channel p => Channel (EitherP e p) Source #
Methods idT :: Monad m => a' -> EitherP e p a' a a' a m r Source # (>->) :: Monad m => (b' -> EitherP e p a' a b' b m r) -> (c' -> EitherP e p b' b c' c m r) -> c' -> EitherP e p a' a c' c m r Source # (<-<) :: Monad m => (c' -> EitherP e p b' b c' c m r) -> (b' -> EitherP e p a' a b' b m r) -> c' -> EitherP e p a' a c' c m r Source #
MonadTrans (p a' a b' b) => MonadTrans (EitherP e p a' a b' b) Source #
Methods lift :: Monad m => m a -> EitherP e p a' a b' b m a #
MFunctor (p a' a b' b) => MFunctor (EitherP e p a' a b' b) Source #
Methods mapT :: (Monad m, Monad n) => (forall c. m c -> n c) -> EitherP e p a' a b' b m b -> EitherP e p a' a b' b n b Source #
Monad (p a' a b' b m) => Monad (EitherP e p a' a b' b m) Source #
Methods (>>=) :: EitherP e p a' a b' b m a -> (a -> EitherP e p a' a b' b m b) -> EitherP e p a' a b' b m b # (>>) :: EitherP e p a' a b' b m a -> EitherP e p a' a b' b m b -> EitherP e p a' a b' b m b # return :: a -> EitherP e p a' a b' b m a # fail :: String -> EitherP e p a' a b' b m a #
Monad (p a' a b' b m) => Functor (EitherP e p a' a b' b m) Source #
Methods fmap :: (a -> b) -> EitherP e p a' a b' b m a -> EitherP e p a' a b' b m b # (<$) :: a -> EitherP e p a' a b' b m b -> EitherP e p a' a b' b m a #
Monad (p a' a b' b m) => Applicative (EitherP e p a' a b' b m) Source #
Methods pure :: a -> EitherP e p a' a b' b m a # (<>) :: EitherP e p a' a b' b m (a -> b) -> EitherP e p a' a b' b m a -> EitherP e p a' a b' b m b # (>) :: EitherP e p a' a b' b m a -> EitherP e p a' a b' b m b -> EitherP e p a' a b' b m b # (<*) :: EitherP e p a' a b' b m a -> EitherP e p a' a b' b m b -> EitherP e p a' a b' b m a #
MonadIO (p a' a b' b m) => MonadIO (EitherP e p a' a b' b m) Source #
Methods liftIO :: IO a -> EitherP e p a' a b' b m a #
MonadPlus (p a' a b' b m) => Alternative (EitherP e p a' a b' b m) Source #
Methods empty :: EitherP e p a' a b' b m a # (<\|>) :: EitherP e p a' a b' b m a -> EitherP e p a' a b' b m a -> EitherP e p a' a b' b m a # some :: EitherP e p a' a b' b m a -> EitherP e p a' a b' b m [a] # many :: EitherP e p a' a b' b m a -> EitherP e p a' a b' b m [a] #
MonadPlus (p a' a b' b m) => MonadPlus (EitherP e p a' a b' b m) Source #
Methods mzero :: EitherP e p a' a b' b m a # mplus :: EitherP e p a' a b' b m a -> EitherP e p a' a b' b m a -> EitherP e p a' a b' b m a #

runEitherK :: (q -> EitherP e p a' a b' b m r) -> q -> p a' a b' b m (Either e r) Source #

Run an EitherP 'K'leisi arrow, returning either a Left or Right

Either operations

left :: Monad (p a' a b' b m) => e -> EitherP e p a' a b' b m r Source #

Abort the computation and return a Left result

right :: Monad (p a' a b' b m) => r -> EitherP e p a' a b' b m r Source #

Synonym for return

Symmetric monad

EitherP forms a second symmetric monad over the left type variable.

throw is symmetric to return

catch is symmetric to (>>=)

These two functions obey the monad laws:

catch m throw = m

catch (throw e) f = f e

catch (catch m f) g = catch m (\e -> catch (f e) g)

throw :: Monad (p a' a b' b m) => e -> EitherP e p a' a b' b m r Source #

Synonym for left

catch Source #

Arguments

:: Monad (p a' a b' b m)
=> EitherP e p a' a b' b m r	Original computation
-> (e -> EitherP f p a' a b' b m r)	Handler
-> EitherP f p a' a b' b m r	Handled computation

Resume from an aborted operation

handle Source #

Arguments

:: Monad (p a' a b' b m)
=> (e -> EitherP f p a' a b' b m r)	Handler
-> EitherP e p a' a b' b m r	Original computation
-> EitherP f p a' a b' b m r	Handled computation

catch with the arguments flipped