Control.Monad.Trans.MultiReader.Lazy

The multi-valued version of mtl's Reader / ReaderT

MultiReaderT

newtype MultiReaderT x m a

A Reader transformer monad patameterized by:

• x - The list of types constituting the environment / input (to be read),
• m - The inner monad.

MultiReaderT corresponds to mtl's ReaderT, 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,

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

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

Constructors

MultiReaderT

Fields

• runMultiReaderTRaw :: StateT (HList x) m a

Instances

MonadState s m => MonadState s (MultiReaderT c m)

Methods

get :: MultiReaderT c m s

put :: s -> MultiReaderT c m ()

state :: (s -> (a, s)) -> MultiReaderT c m a

MonadWriter w m => MonadWriter w (MultiReaderT c m)

Methods

writer :: (a, w) -> MultiReaderT c m a

tell :: w -> MultiReaderT c m ()

listen :: MultiReaderT c m a -> MultiReaderT c m (a, w)

pass :: MultiReaderT c m (a, w -> w) -> MultiReaderT c m a

MonadBase b m => MonadBase b (MultiReaderT r m)

Methods

liftBase :: b α -> MultiReaderT r m α

MonadBaseControl b m => MonadBaseControl b (MultiReaderT r m)

Associated Types

type StM (MultiReaderT r m :: * -> *) a :: *

Methods

liftBaseWith :: (RunInBase (MultiReaderT r m) b -> b a) -> MultiReaderT r m a

restoreM :: StM (MultiReaderT r m) a -> MultiReaderT r m a

(Monad m, ContainsType a c) => MonadMultiReader a (MultiReaderT c m)

Methods

mAsk :: MultiReaderT c m a

MonadTrans (MultiReaderT x)

Methods

lift :: Monad m => m a -> MultiReaderT x m a

MonadTransControl (MultiReaderT r)

Associated Types

type StT (MultiReaderT r :: (* -> *) -> * -> *) a :: *

Methods

liftWith :: Monad m => (Run (MultiReaderT r) -> m a) -> MultiReaderT r m a

restoreT :: Monad m => m (StT (MultiReaderT r) a) -> MultiReaderT r m a

Monad m => Monad (MultiReaderT x m)

Methods

(>>=) :: MultiReaderT x m a -> (a -> MultiReaderT x m b) -> MultiReaderT x m b

(>>) :: MultiReaderT x m a -> MultiReaderT x m b -> MultiReaderT x m b

return :: a -> MultiReaderT x m a

fail :: String -> MultiReaderT x m a

Functor f => Functor (MultiReaderT x f)

Methods

fmap :: (a -> b) -> MultiReaderT x f a -> MultiReaderT x f b

(<$) :: a -> MultiReaderT x f b -> MultiReaderT x f a

MonadFix m => MonadFix (MultiReaderT r m)

Methods

mfix :: (a -> MultiReaderT r m a) -> MultiReaderT r m a

(Applicative m, Monad m) => Applicative (MultiReaderT x m)

Methods

pure :: a -> MultiReaderT x m a

(<*>) :: MultiReaderT x m (a -> b) -> MultiReaderT x m a -> MultiReaderT x m b

(*>) :: MultiReaderT x m a -> MultiReaderT x m b -> MultiReaderT x m b

(<*) :: MultiReaderT x m a -> MultiReaderT x m b -> MultiReaderT x m a

MonadIO m => MonadIO (MultiReaderT c m)

Methods

liftIO :: IO a -> MultiReaderT c m a

(Functor m, Applicative m, MonadPlus m) => Alternative (MultiReaderT c m)

Methods

empty :: MultiReaderT c m a

(<|>) :: MultiReaderT c m a -> MultiReaderT c m a -> MultiReaderT c m a

some :: MultiReaderT c m a -> MultiReaderT c m [a]

many :: MultiReaderT c m a -> MultiReaderT c m [a]

MonadPlus m => MonadPlus (MultiReaderT c m)

Methods

mzero :: MultiReaderT c m a

mplus :: MultiReaderT c m a -> MultiReaderT c m a -> MultiReaderT c m a

type StT (MultiReaderT r) a

type StT (MultiReaderT r) a = (a, HList r)

type StM (MultiReaderT r m) a

type StM (MultiReaderT r m) a = ComposeSt (MultiReaderT r) m a

type MultiReaderTNull = MultiReaderT '[]

A MultiReader transformer carrying an empty state.

type MultiReader x = MultiReaderT x Identity

A reader monad parameterized by the list of types x of the environment / input to carry.

Similar to Reader r = ReaderT r Identity

MonadMultiReader class

class Monad m => MonadMultiReader a m where

All methods must be defined.

The idea is: Any monad stack is instance of MonadMultiReader a, iff the stack contains a MultiReaderT x with a element of x.

Minimal complete definition

mAsk

Methods

mAsk :: m a

Instances

(MonadTrans t, Monad (t m), MonadMultiReader a m) => MonadMultiReader a (t m)

Methods

mAsk :: t m a

(Monad m, ContainsType a c) => MonadMultiReader a (MultiReaderT c m)

Methods

mAsk :: MultiReaderT c m a

(Monad m, ContainsType a c) => MonadMultiReader a (MultiReaderT c m)

Methods

mAsk :: MultiReaderT c m a

(Monad m, ContainsType a r) => MonadMultiReader a (MultiRWST r w s m)

Methods

mAsk :: MultiRWST r w s m a

(Monad m, ContainsType a r) => MonadMultiReader a (MultiRWST r w s m)

Methods

mAsk :: MultiRWST r w s m a

run-functions

runMultiReaderT :: Monad m => HList r -> MultiReaderT r m a -> m a

runMultiReaderT_ :: Functor m => HList r -> MultiReaderT r m a -> m ()

runMultiReaderTNil :: Monad m => MultiReaderT '[] m a -> m a

runMultiReaderTNil_ :: Functor m => MultiReaderT '[] m a -> m ()

with-functions (single reader)

withMultiReader :: Monad m => r -> MultiReaderT (r ': rs) m a -> MultiReaderT rs m a

withMultiReader_ :: (Functor m, Monad m) => r -> MultiReaderT (r ': rs) m a -> MultiReaderT rs m ()

with-functions (multiple readers)

withMultiReaders :: Monad m => HList r1 -> MultiReaderT (Append r1 r2) m a -> MultiReaderT r2 m a

withMultiReaders_ :: (Functor m, Monad m) => HList r1 -> MultiReaderT (Append r1 r2) m a -> MultiReaderT r2 m ()

without-function (single reader)

withoutMultiReader :: Monad m => MultiReaderT rs m a -> MultiReaderT (r ': rs) m a

inflate-function (run ReaderT in MultiReaderT)

inflateReader :: (Monad m, ContainsType r rs) => ReaderT r m a -> MultiReaderT rs m a

other functions

mapMultiReaderT :: (m (a, HList w) -> m' (a', HList w)) -> MultiReaderT w m a -> MultiReaderT w m' a'

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

Note that there is a difference to mtl's ReaderT, where it is not possible to modify the environment.

mGetRaw :: Monad m => MultiReaderT a m (HList a)

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

mPutRaw :: Monad m => HList s -> MultiReaderT s m ()