Control.Monad.Levels.RWS.Lazy

Note that the original definitions are used for the various reader, writer and state computations: as such, if there is (for example) another level that satisfies 'IsReader r' above the one that satisfies 'IsRWS r w s' in the stack, then calling ask will use the higher level.

Documentation

newtype RWST r w s m a :: * -> * -> * -> (* -> *) -> * -> *

A monad transformer adding reading an environment of type r, collecting an output of type w and updating a state of type s to an inner monad m.

Constructors

RWST

Fields

runRWST :: r -> s -> m (a, s, w)

Instances

(MonadTower m, Monoid w) => IsRWS r w s (RWST r w s m)

(MonadTower m, Monoid w) => IsReader r (RWST r w s m)

(MonadTower m, Monoid w) => IsState s (RWST r w s m)

(Monoid w, MonadTower m) => IsWriter w (RWST r w s m)

Monoid w => MonadTrans (RWST r w s)

(Monoid w, Functor m, MonadPlus m) => Alternative (RWST r w s m)

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

Functor m => Functor (RWST r w s m)

(Monoid w, MonadFix m) => MonadFix (RWST r w s m)

(Monoid w, MonadPlus m) => MonadPlus (RWST r w s m)

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

(Monoid w, MonadIO m) => MonadIO (RWST r w s m)

(Monoid w, MonadTower m) => MonadLevel_ (RWST r w s m)

(Monoid w, MonadTower m) => MonadTower_ (RWST r w s m)

type LowerMonad (RWST r w s m) = m

type WithLower_ (RWST r w s m) = AddIG

type AllowOtherValues (RWST r w s m) = True

type DefaultAllowConstraints (RWST r w s m) = True

type BaseMonad (RWST r w s m) = BaseMonad m

type InnerValue (RWST r w s m) a = (a, s, w)

module Control.Monad.Levels.RWS