Safe Haskell | None |
---|---|
Language | Haskell2010 |
Foundation.Monad.Reader
Contents
Description
The Reader monad transformer.
This is useful to keep a non-modifiable value in a context
- class Monad m => MonadReader m where
- type ReaderContext m
- ask :: m (ReaderContext m)
- data ReaderT r m a
- runReaderT :: ReaderT r m a -> r -> m a
MonadReader
class Monad m => MonadReader m where
Associated Types
type ReaderContext m
Methods
ask :: m (ReaderContext m)
Instances
Monad m => MonadReader (ReaderT r m) |
ReaderT
data ReaderT r m a
Reader Transformer
Instances
MonadTrans (ReaderT r) | |
Monad m => Monad (ReaderT r m) | |
Functor m => Functor (ReaderT r m) | |
Applicative m => Applicative (ReaderT r m) | |
MonadIO m => MonadIO (ReaderT r m) | |
MonadCatch m => MonadCatch (ReaderT r m) | |
MonadThrow m => MonadThrow (ReaderT r m) | |
MonadFailure m => MonadFailure (ReaderT r m) | |
Monad m => MonadReader (ReaderT r m) | |
type Failure (ReaderT r m) = Failure m | |
type ReaderContext (ReaderT r m) = r |
runReaderT :: ReaderT r m a -> r -> m a