Control.Monad.Context

This is just like Control.Monad.Reader.Class except you can access the context of any Reader in the monad stack instead of just the top one as long as the context types are different. If two or more readers in the stack have the same context type you get the context of the top one.

Documentation

class Monad m => Context x m where

Same as MonadReader but without functional dependency so the same monad can have multiple contexts with different types

Methods

context :: m x

Get the context in the Reader in the monad stack that has x context type. Analogous to ask.

push :: (x -> x) -> m a -> m a

Push new context in the Reader in the monad stack that has x context type. Analogous to local

Instances

Monad m => Context Connection (Connected m)

Monad m => Context MasterOrSlaveOk (Connected m)

Monad m => Context WriteMode (Connected m)

(Context x m, Error e) => Context x (ErrorT e m)

Context x m => Context x (ReaderT r m)

Monad m => Context x (ReaderT x m)