DeepControl.Monad.Reader

Documentation

class Monad m => MonadReader r m | m -> r where

See examples in Control.Monad.Reader. Note, the partially applied function type (->) r is a simple reader monad. See the instance declaration below.

Minimal complete definition

(ask | reader), local

Methods

ask :: m r

Retrieves the monad environment.

local

Arguments

:: (r -> r)

The function to modify the environment.

-> m a

Reader to run in the modified environment.

-> m a

Executes a computation in a modified environment.

reader

Arguments

:: (r -> a)

The selector function to apply to the environment.

-> m a

Retrieves a function of the current environment.

Instances

MonadReader r m => MonadReader r (MaybeT m)

MonadReader r m => MonadReader r (ListT m)

MonadReader r m => MonadReader r (IdentityT m)

MonadReader r ((->) r)

MonadReader r (Reader r)

(Monoid w, MonadReader r m) => MonadReader r (WriterT w m)

(Monoid w, MonadReader r m) => MonadReader r (WriterT w m)

MonadReader r m => MonadReader r (StateT s m)

MonadReader r m => MonadReader r (StateT s m)

Monad m => MonadReader r (ReaderT r m)

MonadReader r m => MonadReader r (ExceptT e m)

(Error e, MonadReader r m) => MonadReader r (ErrorT e m)

MonadReader r' m => MonadReader r' (ContT r m)

Monoid w => MonadReader r (RWS r w s)

(Monad m, Monoid w) => MonadReader r (RWST r w s m)

(Monad m, Monoid w) => MonadReader r (RWST r w s m)

asks :: MonadReader r m => (r -> a) -> m a

newtype Reader r a

Constructors

Reader

Fields

runReader :: r -> a

Instances

MonadReader r (Reader r)

Monad (Reader r)

Functor (Reader r)

Applicative (Reader r)