Control.Monad.Ether.Reader.Class

See Control.Monad.Reader.Class.

Documentation

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

See MonadReader.

Minimal complete definition

(ask | reader), local

Methods

ask :: proxy tag -> m r

Retrieves the monad environment.

local

Arguments

:: proxy tag

-> (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

:: proxy tag

-> (r -> a)

The selector function to apply to the environment.

-> m a

Retrieves a function of the current environment.

Instances

(LiftLocal t, Monad (t m), MonadReader k tag r m) => MonadReader k tag r (t m)

(Monad m, (~) * r r') => MonadReader k tag r (ReaderT k tag r' m)

asks

Arguments

:: MonadReader tag r m

=> proxy tag

-> (r -> a)

The selector function to apply to the environment.

-> m a

Retrieves a function of the current environment.