Uncurried.StateT

newtype StateT :: Type -> (Type -> Type) -> Type -> Typenewtype StateT s m a

The state monad transformer, implemented as a newtype over RWSET. Note that it's not recommended to stack newtypes of RWSET together as it incurs an indeterminate performance penalty that would otherwise be solved by just using RWSET.

Constructors

• StateT (RWSET Unit Unit s Void m a)

Instances

• Functor (StateT s m)
• Apply (StateT s m)
• Applicative (StateT s m)
• Bind (StateT s m)
• Monad (StateT s m)
• (MonadEffect m) => MonadEffect (StateT s m)
• MonadRec (StateT s m)
• MonadState s (StateT s m)
• MonadTrans (StateT s)
• (Semigroup a) => Semigroup (StateT s m a)
• (Monoid a) => Monoid (StateT s m a)
• Lazy (StateT s m a)
• (MonadAsk r m) => MonadAsk r (StateT s m)
• (MonadRec m, MonadReader r m) => MonadReader r (StateT s m)
• (Monoid w, MonadTell w m) => MonadTell w (StateT s m)
• (Monoid w, MonadRec m, MonadWriter w m) => MonadWriter w (StateT s m)
• (MonadThrow e m) => MonadThrow e (StateT s m)
• (MonadRec m, MonadError e m) => MonadError e (StateT s m)

stateT :: forall s m a. Functor m => (s -> m (a /\ s)) -> StateT s m a

Construct a StateT given a function that treads through some state.

runStateT :: forall s m a. MonadRec m => s -> StateT s m a -> m (a /\ s)

Runs a computation inside of StateT.

evalStateT :: forall s m a. MonadRec m => s -> StateT s m a -> m a

Runs a computation inside of StateT, discarding the final state.

execStateT :: forall s m a. MonadRec m => s -> StateT s m a -> m s

Runs a computation inside of StateT, discarding the final result.

hoistStateT :: forall s m n a. (m ~> n) -> StateT s m a -> StateT s n a

Modifies the monadic context of a StateT.

mapStateT :: forall s m1 m2 a1 a2. MonadRec m1 => Functor m2 => (m1 (a1 /\ s) -> m2 (a2 /\ s)) -> StateT s m1 a1 -> StateT s m2 a2

Modifies the result type of a StateT.

withStateT :: forall s m a. (s -> s) -> StateT s m a -> StateT s m a

Modifies the state of a StateT.