Moduleadjunctions-4.4.4Haskell2010

Control.Monad.Representable.State

A generalized State monad, parameterized by a Representable functor. The representation of that functor serves as the state.

Synopsis

type State
value runState
value evalState
value execState
value mapState
newtype StateT
value stateT
value runStateT
value evalStateT
value execStateT
value mapStateT
value liftCallCC
value liftCallCC'
class MonadState

Packageadjunctions-4.4.4
Exports14
LanguageHaskell2010
LicenceBSD-2-Clause
SourceState.hs

typetype State (g :: Type -> Type) = StateT g Identity

Source#

A memoized state monad parameterized by a representable functor g, where the representatation of g, Rep g is the state to carry.

The return function leaves the state unchanged, while >>= uses the final state of the first computation as the initial state of the second.

valuerunState

:: Representable g
=> State g a
state-passing computation to execute
-> Rep g
initial state
-> (a, Rep g)
return value and final state

Source#

Unwrap a state monad computation as a function. (The inverse of state.)

valueevalState

:: Representable g
=> State g a
state-passing computation to execute
-> Rep g
initial value
-> a
return value of the state computation

Source#

Evaluate a state computation with the given initial state and return the final value, discarding the final state.

```
evalState m s = fst (runState m s)
```

valueexecState

:: Representable g
=> State g a
state-passing computation to execute
-> Rep g
initial value
-> Rep g
final state

Source#

Evaluate a state computation with the given initial state and return the final state, discarding the final value.

```
execState m s = snd (runState m s)
```

valuemapState

:: Functor g
=> (a, Rep g) -> (b, Rep g)
-> State g a
-> State g b

Source#

Map both the return value and final state of a computation using the given function.

runState (mapState f m) = f . runState m

newtypenewtype StateT (g :: Type -> Type) (m :: Type -> Type) a

Source#

A state transformer monad parameterized by:

g - A representable functor used to memoize results for a state Rep g
m - The inner monad.

The return function leaves the state unchanged, while >>= uses the final state of the first computation as the initial state of the second.

Constructors

StateT
- getStateT :: g (m (a, Rep g))

Instances12MonadReader, MonadState, MonadWriter, MonadFree, MonadTrans, BindTrans, …

(Representable g, MonadReader e m) => MonadReader e (StateT g m)Defined in adjunctions-4.4.4 · Control.Monad.Representable.State
(Representable g, Monad m, Rep g ~ s) => MonadState s (StateT g m)Defined in adjunctions-4.4.4 · Control.Monad.Representable.State
(Representable g, MonadWriter w m) => MonadWriter w (StateT g m)Defined in adjunctions-4.4.4 · Control.Monad.Representable.State
(Functor f, Representable g, MonadFree f m) => MonadFree f (StateT g m)Defined in adjunctions-4.4.4 · Control.Monad.Representable.State
Representable f => MonadTrans (StateT f)Defined in adjunctions-4.4.4 · Control.Monad.Representable.State
Representable f => BindTrans (StateT f)Defined in adjunctions-4.4.4 · Control.Monad.Representable.State
(Representable g, Monad m) => Monad (StateT g m)Defined in adjunctions-4.4.4 · Control.Monad.Representable.State
(Functor g, Functor m) => Functor (StateT g m)Defined in adjunctions-4.4.4 · Control.Monad.Representable.State
(Representable g, Functor m, Monad m) => Applicative (StateT g m)Defined in adjunctions-4.4.4 · Control.Monad.Representable.State
(Representable g, MonadCont m) => MonadCont (StateT g m)Defined in adjunctions-4.4.4 · Control.Monad.Representable.State
(Representable g, Bind m) => Apply (StateT g m)Defined in adjunctions-4.4.4 · Control.Monad.Representable.State
(Representable g, Bind m) => Bind (StateT g m)Defined in adjunctions-4.4.4 · Control.Monad.Representable.State

valuestateT :: Representable g => (Rep g -> m (a, Rep g)) -> StateT g m a

valuerunStateT :: Representable g => StateT g m a -> Rep g -> m (a, Rep g)

valueevalStateT :: (Representable g, Monad m) => StateT g m a -> Rep g -> m a

Source#

Evaluate a state computation with the given initial state and return the final value, discarding the final state.

evalStateT m s = liftM fst (runStateT m s)

valueexecStateT

:: (Representable g, Monad m)
=> StateT g m a
-> Rep g
-> m (Rep g)

Source#

Evaluate a state computation with the given initial state and return the final state, discarding the final value.

execStateT m s = liftM snd (runStateT m s)

valuemapStateT

:: Functor g
=> m (a, Rep g) -> n (b, Rep g)
-> StateT g m a
-> StateT g n b

valueliftCallCC

:: Representable g
=> (((a, Rep g) -> m (b, Rep g)) -> m (a, Rep g)) -> m (a, Rep g)
-> (a -> StateT g m b) -> StateT g m a
-> StateT g m a

Source#

Uniform lifting of a callCC operation to the new monad. This version rolls back to the original state on entering the continuation.

valueliftCallCC'

:: Representable g
=> (((a, Rep g) -> m (b, Rep g)) -> m (a, Rep g)) -> m (a, Rep g)
-> (a -> StateT g m b) -> StateT g m a
-> StateT g m a

Source#

In-situ lifting of a callCC operation to the new monad. This version uses the current state on entering the continuation. It does not satisfy the laws of a monad transformer.

classclass Monad m => MonadState s (m :: Type -> Type) | m -> s where

Source#

Minimal definition is either both of get and put or just state

Methods

get :: m s
Return the state from the internals of the monad.
put :: s -> m ()
Replace the state inside the monad.
state :: (s -> (a, s)) -> m a
Embed a simple state action into the monad.

Instances25MonadState, …

MonadState s m => MonadState s (CatchT m)Defined in exceptions-0.10.12 · Control.Monad.Catch.Pure
MonadState s m => MonadState s (Free m)Defined in free-5.2 · Control.Monad.Free
MonadState s m => MonadState s (Free m)Defined in free-5.2 · Control.Monad.Free.Ap
MonadState s m => MonadState s (F m)Defined in free-5.2 · Control.Monad.Free.Church
MonadState s m => MonadState s (IterT m)Defined in free-5.2 · Control.Monad.Trans.Iter
MonadState s m => MonadState s (MaybeT m)Defined in mtl-2.3.2 · Control.Monad.State.Class
Monad m => MonadState s (StateT s m)Defined in mtl-2.3.2 · Control.Monad.State.Class
Monad m => MonadState s (StateT s m)Defined in mtl-2.3.2 · Control.Monad.State.Class
MonadState s m => MonadState s (FT f m)Defined in free-5.2 · Control.Monad.Trans.Free.Church
MonadState s m => MonadState s (ExceptT e m)Defined in mtl-2.3.2 · Control.Monad.State.Class
MonadState s m => MonadState s (IdentityT m)Defined in mtl-2.3.2 · Control.Monad.State.Class
MonadState s m => MonadState s (ReaderT r m)Defined in mtl-2.3.2 · Control.Monad.State.Class
MonadState s m => MonadState s (SelectT r m)Defined in mtl-2.3.2 · Control.Monad.State.Class
(Representable g, Monad m, Rep g ~ s) => MonadState s (StateT g m)Defined in adjunctions-4.4.4 · Control.Monad.Representable.State
(Applicative f, MonadState s m) => MonadState s (FreeT f m)Defined in free-5.2 · Control.Monad.Trans.Free.Ap
(Functor f, MonadState s m) => MonadState s (FreeT f m)Defined in free-5.2 · Control.Monad.Trans.Free
(Monoid w, MonadState s m) => MonadState s (AccumT w m)Defined in mtl-2.3.2 · Control.Monad.State.Class
(Monoid w, MonadState s m) => MonadState s (WriterT w m)Defined in mtl-2.3.2 · Control.Monad.State.Class
(Monoid w, MonadState s m) => MonadState s (WriterT w m)Defined in mtl-2.3.2 · Control.Monad.State.Class
(Monoid w, MonadState s m) => MonadState s (WriterT w m)Defined in mtl-2.3.2 · Control.Monad.State.Class
MonadState s m => MonadState s (ContT r m)Defined in mtl-2.3.2 · Control.Monad.State.Class
(MonadState s m, MonadState s n) => MonadState s (Product m n)Defined in mtl-2.3.2 · Control.Monad.State.Class
(Monad m, Monoid w) => MonadState s (RWST r w s m)Defined in mtl-2.3.2 · Control.Monad.State.Class
(Monad m, Monoid w) => MonadState s (RWST r w s m)Defined in mtl-2.3.2 · Control.Monad.State.Class
(Monad m, Monoid w) => MonadState s (RWST r w s m)Defined in mtl-2.3.2 · Control.Monad.State.Class