data-accessor-mtl-0.2.0.5: Use Accessor to access state in mtl State monad class
Safe HaskellSafe-Inferred
LanguageHaskell98

Data.Accessor.Monad.MTL.State

Description

Access helper functions in the State monad class

Synopsis

accessors in the form of actions in the state monad

set :: MonadState r m => T r a -> a -> m () Source #

get :: MonadState r m => T r a -> m a Source #

modify :: MonadState r m => T r a -> (a -> a) -> m () Source #

getAndModify :: MonadState r m => T r a -> (a -> a) -> m a Source #

Modify a record element and return its old value.

modifyAndGet :: MonadState r m => T r a -> (a -> a) -> m a Source #

Modify a record element and return its new value.

(%=) :: MonadState r m => T r a -> a -> m () infix 1 Source #

Infix variant of set.

(%:) :: MonadState r m => T r a -> (a -> a) -> m () infix 1 Source #

Infix variant of modify.

lift a state monadic accessor to an accessor of a parent record

lift :: MonadState r mr => T r s -> State s a -> mr a Source #

liftT :: (Monad m, MonadTrans t, MonadState r (t m)) => T r s -> StateT s m a -> t m a Source #