Safe Haskell	Safe
Language	Haskell2010

Control.Monad.Trans.MultiWriter

Contents

MultiWriterT
MonadMultiWriter class
run-functions
with-functions (single Writer)
with-functions (multiple Writers)
other functions

Description

The multi-valued version of mtl's Writer / WriterT / MonadWriter

Synopsis

MultiWriterT

newtype MultiWriterT x m a #

A Writer transformer monad patameterized by:

x - The list of types that can be written (Monoid instances).
m - The inner monad.

MultiWriterT corresponds to mtl's WriterT, but can contain a heterogenous list of types.

This heterogenous list is represented using Types.Data.List, i.e:

'[] - The empty list,
a ': b - A list where a is an arbitrary type and b is the rest list.

For example,

MultiWriterT '[Int, Bool] :: (* -> *) -> (* -> *)

is a Writer transformer containing the types [Int, Bool].

Constructors

MultiWriterT
Fields runMultiWriterTRaw :: StateT (HList x) m a

Instances

(Monad m, ContainsType a c, Monoid a) => MonadMultiWriter a (MultiWriterT c m) #
Methods mTell :: a -> MultiWriterT c m () #
MonadState s m => MonadState s (MultiWriterT c m) #
Methods get :: MultiWriterT c m s put :: s -> MultiWriterT c m () state :: (s -> (a, s)) -> MultiWriterT c m a
MonadWriter w m => MonadWriter w (MultiWriterT c m) #
Methods writer :: (a, w) -> MultiWriterT c m a tell :: w -> MultiWriterT c m () listen :: MultiWriterT c m a -> MultiWriterT c m (a, w) pass :: MultiWriterT c m (a, w -> w) -> MultiWriterT c m a
MonadBase b m => MonadBase b (MultiWriterT c m) #
Methods liftBase :: b α -> MultiWriterT c m α
MonadBaseControl b m => MonadBaseControl b (MultiWriterT c m) #
Associated Types type StM (MultiWriterT c m :: * -> ) a :: Methods liftBaseWith :: (RunInBase (MultiWriterT c m) b -> b a) -> MultiWriterT c m a restoreM :: StM (MultiWriterT c m) a -> MultiWriterT c m a
MonadTrans (MultiWriterT x) #
Methods lift :: Monad m => m a -> MultiWriterT x m a #
MonadTransControl (MultiWriterT c) #
Associated Types type StT (MultiWriterT c :: (* -> ) -> -> ) a :: Methods liftWith :: Monad m => (Run (MultiWriterT c) -> m a) -> MultiWriterT c m a restoreT :: Monad m => m (StT (MultiWriterT c) a) -> MultiWriterT c m a
Monad m => Monad (MultiWriterT x m) #
Methods (>>=) :: MultiWriterT x m a -> (a -> MultiWriterT x m b) -> MultiWriterT x m b # (>>) :: MultiWriterT x m a -> MultiWriterT x m b -> MultiWriterT x m b # return :: a -> MultiWriterT x m a # fail :: String -> MultiWriterT x m a #
Functor f => Functor (MultiWriterT x f) #
Methods fmap :: (a -> b) -> MultiWriterT x f a -> MultiWriterT x f b # (<$) :: a -> MultiWriterT x f b -> MultiWriterT x f a #
MonadFix m => MonadFix (MultiWriterT w m) #
Methods mfix :: (a -> MultiWriterT w m a) -> MultiWriterT w m a #
(Applicative m, Monad m) => Applicative (MultiWriterT x m) #
Methods pure :: a -> MultiWriterT x m a # (<>) :: MultiWriterT x m (a -> b) -> MultiWriterT x m a -> MultiWriterT x m b # (>) :: MultiWriterT x m a -> MultiWriterT x m b -> MultiWriterT x m b # (<*) :: MultiWriterT x m a -> MultiWriterT x m b -> MultiWriterT x m a #
MonadIO m => MonadIO (MultiWriterT c m) #
Methods liftIO :: IO a -> MultiWriterT c m a #
(Functor m, Applicative m, MonadPlus m) => Alternative (MultiWriterT c m) #
Methods empty :: MultiWriterT c m a # (<\|>) :: MultiWriterT c m a -> MultiWriterT c m a -> MultiWriterT c m a # some :: MultiWriterT c m a -> MultiWriterT c m [a] # many :: MultiWriterT c m a -> MultiWriterT c m [a] #
MonadPlus m => MonadPlus (MultiWriterT c m) #
Methods mzero :: MultiWriterT c m a # mplus :: MultiWriterT c m a -> MultiWriterT c m a -> MultiWriterT c m a #
type StT (MultiWriterT c) a #
type StT (MultiWriterT c) a = (a, HList c)
type StM (MultiWriterT c m) a #
type StM (MultiWriterT c m) a = ComposeSt (MultiWriterT c) m a

type MultiWriterTNull = MultiWriterT '[] #

A MultiWriter transformer carrying an empty state.

type MultiWriter x a = MultiWriterT x Identity a #

MonadMultiWriter class

class (Monad m, Monoid a) => MonadMultiWriter a m where #

Minimal complete definition

mTell

Methods

mTell :: a -> m () #

Instances

(MonadTrans t, Monad (t m), MonadMultiWriter a m) => MonadMultiWriter a (t m) #
Methods mTell :: a -> t m () #
(Monad m, ContainsType a c, Monoid a) => MonadMultiWriter a (MultiWriterT c m) #
Methods mTell :: a -> MultiWriterT c m () #
(Monad m, ContainsType a c, Monoid a) => MonadMultiWriter a (MultiWriterT c m) #
Methods mTell :: a -> MultiWriterT c m () #
(Monad m, ContainsType a w, Monoid a) => MonadMultiWriter a (MultiRWST r w s m) #
Methods mTell :: a -> MultiRWST r w s m () #
(Monad m, ContainsType a w, Monoid a) => MonadMultiWriter a (MultiRWST r w s m) #
Methods mTell :: a -> MultiRWST r w s m () #

run-functions

runMultiWriterT :: (Monoid (HList w), Functor m) => MultiWriterT w m a -> m (a, HList w) #

runMultiWriterTAW :: (Monoid (HList w), Functor m) => MultiWriterT w m a -> m (a, HList w) #

runMultiWriterTWA :: (Monoid (HList w), Monad m) => MultiWriterT w m a -> m (HList w, a) #

runMultiWriterTW :: (Monoid (HList w), Monad m) => MultiWriterT w m a -> m (HList w) #

runMultiWriterTNil :: Monad m => MultiWriterT '[] m a -> m a #

runMultiWriterTNil_ :: Functor m => MultiWriterT '[] m a -> m () #

with-functions (single Writer)

withMultiWriter :: (Monoid w, Monad m) => MultiWriterT (w ': ws) m a -> MultiWriterT ws m (a, w) #

withMultiWriterAW :: (Monoid w, Monad m) => MultiWriterT (w ': ws) m a -> MultiWriterT ws m (a, w) #

withMultiWriterWA :: (Monoid w, Monad m) => MultiWriterT (w ': ws) m a -> MultiWriterT ws m (w, a) #

withMultiWriterW :: (Monoid w, Monad m) => MultiWriterT (w ': ws) m a -> MultiWriterT ws m w #

with-functions (multiple Writers)

withMultiWriters :: forall w1 w2 m a. (Monoid (HList w1), Monad m, HInit w1) => MultiWriterT (Append w1 w2) m a -> MultiWriterT w2 m (a, HList w1) #

withMultiWritersAW :: forall w1 w2 m a. (Monoid (HList w1), Monad m, HInit w1) => MultiWriterT (Append w1 w2) m a -> MultiWriterT w2 m (a, HList w1) #

withMultiWritersWA :: forall w1 w2 m a. (Monoid (HList w1), Monad m, HInit w1) => MultiWriterT (Append w1 w2) m a -> MultiWriterT w2 m (HList w1, a) #

withMultiWritersW :: forall w1 w2 m a. (Monoid (HList w1), Monad m, HInit w1) => MultiWriterT (Append w1 w2) m a -> MultiWriterT w2 m (HList w1) #

other functions

mapMultiWriterT :: (m (a, HList w) -> m' (a', HList w)) -> MultiWriterT w m a -> MultiWriterT w m' a' #

Map both the return value and the state of a computation using the given function.

mGetRaw :: Monad m => MultiWriterT a m (HList a) #

A raw extractor of the contained HList (i.e. the complete state).

mPutRaw :: Monad m => HList s -> MultiWriterT s m () #