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Language	GHC2021

Control.Monad.Ology.Specific.StateT

Contents

Orphan instances

Synopsis

get :: forall (m :: Type -> Type) s. Monad m => StateT s m s
newtype StateT s (m :: Type -> Type) a = StateT {
- runStateT :: s -> m (a, s)
}
put :: forall (m :: Type -> Type) s. Monad m => s -> StateT s m ()
type State s = StateT s Identity
runState :: State s a -> s -> (a, s)
execState :: State s a -> s -> s
evalState :: State s a -> s -> a
mapState :: ((a, s) -> (b, s)) -> State s a -> State s b
withState :: (s -> s) -> State s a -> State s a
evalStateT :: Monad m => StateT s m a -> s -> m a
execStateT :: Monad m => StateT s m a -> s -> m s
mapStateT :: (m (a, s) -> n (b, s)) -> StateT s m a -> StateT s n b
withStateT :: forall s (m :: Type -> Type) a. (s -> s) -> StateT s m a -> StateT s m a
state :: forall (m :: Type -> Type) s a. Monad m => (s -> (a, s)) -> StateT s m a
modify :: forall (m :: Type -> Type) s. Monad m => (s -> s) -> StateT s m ()
modify' :: forall (m :: Type -> Type) s. Monad m => (s -> s) -> StateT s m ()
gets :: forall (m :: Type -> Type) s a. Monad m => (s -> a) -> StateT s m a
liftCallCC' :: CallCC m (a, s) (b, s) -> CallCC (StateT s m) a b
modifyM :: Monad m => (s -> m s) -> StateT s m ()
liftWithMVarStateT :: MonadIO m => (MVar s -> m a) -> StateT s m a
mVarRunStateT :: MVar s -> Unlift MonadTunnelIO (StateT s)
mVarRunLocked :: forall (m :: Type -> Type) s. MonadTunnelIO m => MVar s -> m --> m
discardingStateTUnlift :: s -> Unlift MonadIO (StateT s)
dangerousMVarRunStateT :: MVar s -> Unlift MonadIO (StateT s)
liftStateT :: forall f (m :: Type -> Type) s a. (Traversable f, Applicative m) => StateT s m a -> StateT (f s) m (f a)

Documentation

get :: forall (m :: Type -> Type) s. Monad m => StateT s m s #

Fetch the current value of the state within the monad.

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

A state transformer monad parameterized by:

s - The state.
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
Fields runStateT :: s -> m (a, s)

Instances

Instances details

TransConstraint MonadFail (StateT s) Source #

Instance details

Defined in Control.Monad.Ology.Specific.StateT

Methods

hasTransConstraint :: forall (m :: Type -> Type). MonadFail m => Dict (MonadFail (StateT s m)) Source #

TransConstraint MonadFix (StateT s) Source #

Instance details

Defined in Control.Monad.Ology.Specific.StateT

Methods

hasTransConstraint :: forall (m :: Type -> Type). MonadFix m => Dict (MonadFix (StateT s m)) Source #

TransConstraint MonadIO (StateT s) Source #

Instance details

Defined in Control.Monad.Ology.Specific.StateT

Methods

hasTransConstraint :: forall (m :: Type -> Type). MonadIO m => Dict (MonadIO (StateT s m)) Source #

TransConstraint Functor (StateT s) Source #

Instance details

Defined in Control.Monad.Ology.Specific.StateT

Methods

hasTransConstraint :: forall (m :: Type -> Type). Functor m => Dict (Functor (StateT s m)) Source #

TransConstraint Monad (StateT s) Source #

Instance details

Defined in Control.Monad.Ology.Specific.StateT

Methods

hasTransConstraint :: forall (m :: Type -> Type). Monad m => Dict (Monad (StateT s m)) Source #

TransConstraint MonadPlus (StateT s) Source #

Instance details

Defined in Control.Monad.Ology.Specific.StateT

Methods

hasTransConstraint :: forall (m :: Type -> Type). MonadPlus m => Dict (MonadPlus (StateT s m)) Source #

TransConstraint MonadException (StateT s) Source #

Instance details

Defined in Control.Monad.Ology.Specific.StateT

Methods

hasTransConstraint :: forall (m :: Type -> Type). MonadException m => Dict (MonadException (StateT s m)) Source #

MonadCatch e m => MonadCatch e (StateT s m) Source #

Instance details

Defined in Control.Monad.Ology.Specific.StateT

Methods

catch :: StateT s m a -> (e -> StateT s m a) -> StateT s m a Source #

MonadThrow e m => MonadThrow e (StateT s m) Source #

Instance details

Defined in Control.Monad.Ology.Specific.StateT

Methods

throw :: e -> StateT s m a Source #

MonadTransCoerce (StateT a) Source #

Instance details

Defined in Control.Monad.Ology.Specific.StateT

Methods

transCoerce :: forall (m1 :: Type -> Type) (m2 :: Type -> Type). Coercible m1 m2 => Dict (Coercible (StateT a m1) (StateT a m2)) Source #

MonadTransHoist (StateT s) Source #

Instance details

Defined in Control.Monad.Ology.Specific.StateT

Methods

hoist :: forall (m1 :: Type -> Type) (m2 :: Type -> Type). (Monad m1, Monad m2) => (m1 --> m2) -> StateT s m1 --> StateT s m2 Source #

MonadTransTunnel (StateT s) Source #

Instance details

Defined in Control.Monad.Ology.Specific.StateT

Associated Types

type Tunnel (StateT s)
Instance details Defined in Control.Monad.Ology.Specific.StateT type Tunnel (StateT s) = (,) (Endo s)

Methods

tunnel :: Monad m => ((forall (m1 :: Type -> Type) a. Monad m1 => StateT s m1 a -> m1 (Tunnel (StateT s) a)) -> m (Tunnel (StateT s) r)) -> StateT s m r Source #

MonadTransUnlift (StateT s) Source #

Instance details

Defined in Control.Monad.Ology.Specific.StateT

Methods

liftWithUnlift :: MonadIO m => (Unlift MonadTunnelIO (StateT s) -> m r) -> StateT s m r Source #

getDiscardingUnlift :: forall (m :: Type -> Type). Monad m => StateT s m (WUnlift MonadTunnelIO (StateT s)) Source #

MonadTrans (StateT s)

Instance details

Defined in Control.Monad.Trans.State.Lazy

Methods

lift :: Monad m => m a -> StateT s m a #

TransConstraint (MonadCatch e) (StateT s) Source #

Instance details

Defined in Control.Monad.Ology.Specific.StateT

Methods

hasTransConstraint :: forall (m :: Type -> Type). MonadCatch e m => Dict (MonadCatch e (StateT s m)) Source #

TransConstraint (MonadThrow e) (StateT s) Source #

Instance details

Defined in Control.Monad.Ology.Specific.StateT

Methods

hasTransConstraint :: forall (m :: Type -> Type). MonadThrow e m => Dict (MonadThrow e (StateT s m)) Source #

MonadFail m => MonadFail (StateT s m)

Instance details

Defined in Control.Monad.Trans.State.Lazy

Methods

fail :: String -> StateT s m a #

MonadFix m => MonadFix (StateT s m)

Instance details

Defined in Control.Monad.Trans.State.Lazy

Methods

mfix :: (a -> StateT s m a) -> StateT s m a #

MonadIO m => MonadIO (StateT s m)

Instance details

Defined in Control.Monad.Trans.State.Lazy

Methods

liftIO :: IO a -> StateT s m a #

Contravariant m => Contravariant (StateT s m)

Instance details

Defined in Control.Monad.Trans.State.Lazy

Methods

contramap :: (a' -> a) -> StateT s m a -> StateT s m a' #

(>$) :: b -> StateT s m b -> StateT s m a #

(Functor m, MonadPlus m) => Alternative (StateT s m)

Instance details

Defined in Control.Monad.Trans.State.Lazy

Methods

empty :: StateT s m a #

(<|>) :: StateT s m a -> StateT s m a -> StateT s m a #

some :: StateT s m a -> StateT s m [a] #

many :: StateT s m a -> StateT s m [a] #

(Functor m, Monad m) => Applicative (StateT s m)

Instance details

Defined in Control.Monad.Trans.State.Lazy

Methods

pure :: a -> StateT s m a #

(<*>) :: StateT s m (a -> b) -> StateT s m a -> StateT s m b #

liftA2 :: (a -> b -> c) -> StateT s m a -> StateT s m b -> StateT s m c #

(*>) :: StateT s m a -> StateT s m b -> StateT s m b #

(<*) :: StateT s m a -> StateT s m b -> StateT s m a #

Functor m => Functor (StateT s m)

Instance details

Defined in Control.Monad.Trans.State.Lazy

Methods

fmap :: (a -> b) -> StateT s m a -> StateT s m b #

(<$) :: a -> StateT s m b -> StateT s m a #

Monad m => Monad (StateT s m)

Instance details

Defined in Control.Monad.Trans.State.Lazy

Methods

(>>=) :: StateT s m a -> (a -> StateT s m b) -> StateT s m b #

(>>) :: StateT s m a -> StateT s m b -> StateT s m b #

return :: a -> StateT s m a #

MonadPlus m => MonadPlus (StateT s m)

Instance details

Defined in Control.Monad.Trans.State.Lazy

Methods

mzero :: StateT s m a #

mplus :: StateT s m a -> StateT s m a -> StateT s m a #

Invariant m => Invariant (StateT s m)

from the transformers package

Instance details

Defined in Data.Functor.Invariant

Methods

invmap :: (a -> b) -> (b -> a) -> StateT s m a -> StateT s m b #

MonadException m => MonadException (StateT s m) Source #

Instance details

Defined in Control.Monad.Ology.Specific.StateT

Associated Types

type Exc (StateT s m)
Instance details Defined in Control.Monad.Ology.Specific.StateT type Exc (StateT s m) = Exc m

Methods

throwExc :: Exc (StateT s m) -> StateT s m a Source #

catchExc :: StateT s m a -> (Exc (StateT s m) -> StateT s m a) -> StateT s m a Source #

Lifting MonadFix (StateT s :: (Type -> Type) -> Type -> Type)

Instance details

Defined in Data.Constraint.Lifting

Methods

lifting :: forall (a :: Type -> Type). MonadFix a :- MonadFix (StateT s a) #

Lifting MonadIO (StateT s :: (Type -> Type) -> Type -> Type)

Instance details

Defined in Data.Constraint.Lifting

Methods

lifting :: forall (a :: Type -> Type). MonadIO a :- MonadIO (StateT s a) #

Lifting Functor (StateT s :: (Type -> Type) -> Type -> Type)

Instance details

Defined in Data.Constraint.Lifting

Methods

lifting :: forall (a :: Type -> Type). Functor a :- Functor (StateT s a) #

Lifting Monad (StateT s :: (Type -> Type) -> Type -> Type)

Instance details

Defined in Data.Constraint.Lifting

Methods

lifting :: forall (a :: Type -> Type). Monad a :- Monad (StateT s a) #

Lifting MonadPlus (StateT s :: (Type -> Type) -> Type -> Type)

Instance details

Defined in Data.Constraint.Lifting

Methods

lifting :: forall (a :: Type -> Type). MonadPlus a :- MonadPlus (StateT s a) #

Lifting MonadCont (StateT s :: (Type -> Type) -> Type -> Type)

Instance details

Defined in Data.Constraint.Lifting

Methods

lifting :: forall (a :: Type -> Type). MonadCont a :- MonadCont (StateT s a) #

Lifting (MonadError e :: (Type -> Type) -> Constraint) (StateT s :: (Type -> Type) -> Type -> Type)

Instance details

Defined in Data.Constraint.Lifting

Methods

lifting :: forall (a :: Type -> Type). MonadError e a :- MonadError e (StateT s a) #

Lifting (MonadReader r :: (Type -> Type) -> Constraint) (StateT s :: (Type -> Type) -> Type -> Type)

Instance details

Defined in Data.Constraint.Lifting

Methods

lifting :: forall (a :: Type -> Type). MonadReader r a :- MonadReader r (StateT s a) #

Generic (StateT s m a)

Instance details

Defined in Control.Monad.Trans.State.Lazy

Associated Types

type Rep (StateT s m a)
Instance details Defined in Control.Monad.Trans.State.Lazy type Rep (StateT s m a) = D1 ('MetaData "StateT" "Control.Monad.Trans.State.Lazy" "transformers-0.6.1.0-inplace" 'True) (C1 ('MetaCons "StateT" 'PrefixI 'True) (S1 ('MetaSel ('Just "runStateT") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (s -> m (a, s)))))

Methods

from :: StateT s m a -> Rep (StateT s m a) x #

to :: Rep (StateT s m a) x -> StateT s m a #

type Tunnel (StateT s) Source #

Instance details

Defined in Control.Monad.Ology.Specific.StateT

type Tunnel (StateT s) = (,) (Endo s)

type Exc (StateT s m) Source #

Instance details

Defined in Control.Monad.Ology.Specific.StateT

type Exc (StateT s m) = Exc m

type Rep (StateT s m a)

Instance details

Defined in Control.Monad.Trans.State.Lazy

type Rep (StateT s m a) = D1 ('MetaData "StateT" "Control.Monad.Trans.State.Lazy" "transformers-0.6.1.0-inplace" 'True) (C1 ('MetaCons "StateT" 'PrefixI 'True) (S1 ('MetaSel ('Just "runStateT") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (s -> m (a, s)))))

put :: forall (m :: Type -> Type) s. Monad m => s -> StateT s m () #

put s sets the state within the monad to s.

type State s = StateT s Identity #

A state monad parameterized by the type s of 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.

runState #

Arguments

:: State s a	state-passing computation to execute
-> s	initial state
-> (a, s)	return value and final state

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

execState #

Arguments

:: State s a	state-passing computation to execute
-> s	initial value
-> s	final state

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)
```

evalState #

Arguments

:: State s a	state-passing computation to execute
-> s	initial value
-> a	return value of the state computation

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)
```

mapState :: ((a, s) -> (b, s)) -> State s a -> State s b #

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

runState (mapState f m) = f . runState m

withState :: (s -> s) -> State s a -> State s a #

withState f m executes action m on a state modified by applying f.

```
withState f m = modify f >> m
```

evalStateT :: Monad m => StateT s m a -> s -> m a #

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)

execStateT :: Monad m => StateT s m a -> s -> m s #

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)

mapStateT :: (m (a, s) -> n (b, s)) -> StateT s m a -> StateT s n b #

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

runStateT (mapStateT f m) = f . runStateT m

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

withStateT f m executes action m on a state modified by applying f.

```
withStateT f m = modify f >> m
```

state #

Arguments

:: forall (m :: Type -> Type) s a. Monad m
=> (s -> (a, s))	pure state transformer
-> StateT s m a	equivalent state-passing computation

Construct a state monad computation from a function. (The inverse of runState.)

modify :: forall (m :: Type -> Type) s. Monad m => (s -> s) -> StateT s m () #

modify f is an action that updates the state to the result of applying f to the current state.

```
modify f = get >>= (put . f)
```

modify' :: forall (m :: Type -> Type) s. Monad m => (s -> s) -> StateT s m () #

A variant of modify in which the computation is strict in the new state.

```
modify' f = get >>= (($!) put . f)
```

gets :: forall (m :: Type -> Type) s a. Monad m => (s -> a) -> StateT s m a #

Get a specific component of the state, using a projection function supplied.

```
gets f = liftM f get
```

liftCallCC' :: CallCC m (a, s) (b, s) -> CallCC (StateT s m) a b #

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 uniformity property (see Control.Monad.Signatures).

modifyM :: Monad m => (s -> m s) -> StateT s m () #

A variant of modify in which the new state is generated by a monadic action.

liftWithMVarStateT :: MonadIO m => (MVar s -> m a) -> StateT s m a Source #

mVarRunStateT :: MVar s -> Unlift MonadTunnelIO (StateT s) Source #

Run the StateT on an MVar, taking the initial state and putting the final state.

mVarRunLocked :: forall (m :: Type -> Type) s. MonadTunnelIO m => MVar s -> m --> m Source #

Take the MVar before and put it back after.

discardingStateTUnlift :: s -> Unlift MonadIO (StateT s) Source #

dangerousMVarRunStateT :: MVar s -> Unlift MonadIO (StateT s) Source #

Dangerous, because the MVar won't be released on exception.

liftStateT :: forall f (m :: Type -> Type) s a. (Traversable f, Applicative m) => StateT s m a -> StateT (f s) m (f a) Source #

Orphan instances

TransConstraint MonadFail (StateT s) Source #

Instance details

Methods

hasTransConstraint :: forall (m :: Type -> Type). MonadFail m => Dict (MonadFail (StateT s m)) Source #

TransConstraint MonadFix (StateT s) Source #

Instance details

Methods

hasTransConstraint :: forall (m :: Type -> Type). MonadFix m => Dict (MonadFix (StateT s m)) Source #

TransConstraint MonadIO (StateT s) Source #

Instance details

Methods

hasTransConstraint :: forall (m :: Type -> Type). MonadIO m => Dict (MonadIO (StateT s m)) Source #

TransConstraint Functor (StateT s) Source #

Instance details

Methods

hasTransConstraint :: forall (m :: Type -> Type). Functor m => Dict (Functor (StateT s m)) Source #

TransConstraint Monad (StateT s) Source #

Instance details

Methods

hasTransConstraint :: forall (m :: Type -> Type). Monad m => Dict (Monad (StateT s m)) Source #

TransConstraint MonadPlus (StateT s) Source #

Instance details

Methods

hasTransConstraint :: forall (m :: Type -> Type). MonadPlus m => Dict (MonadPlus (StateT s m)) Source #

TransConstraint MonadException (StateT s) Source #

Instance details

Methods

hasTransConstraint :: forall (m :: Type -> Type). MonadException m => Dict (MonadException (StateT s m)) Source #

MonadCatch e m => MonadCatch e (StateT s m) Source #

Instance details

Methods

catch :: StateT s m a -> (e -> StateT s m a) -> StateT s m a Source #

MonadThrow e m => MonadThrow e (StateT s m) Source #

Instance details

Methods

throw :: e -> StateT s m a Source #

MonadTransCoerce (StateT a) Source #

Instance details

Methods

transCoerce :: forall (m1 :: Type -> Type) (m2 :: Type -> Type). Coercible m1 m2 => Dict (Coercible (StateT a m1) (StateT a m2)) Source #

MonadTransHoist (StateT s) Source #

Instance details

Methods

hoist :: forall (m1 :: Type -> Type) (m2 :: Type -> Type). (Monad m1, Monad m2) => (m1 --> m2) -> StateT s m1 --> StateT s m2 Source #

MonadTransTunnel (StateT s) Source #

Instance details

Associated Types

type Tunnel (StateT s)
Instance details Defined in Control.Monad.Ology.Specific.StateT type Tunnel (StateT s) = (,) (Endo s)

Methods

tunnel :: Monad m => ((forall (m1 :: Type -> Type) a. Monad m1 => StateT s m1 a -> m1 (Tunnel (StateT s) a)) -> m (Tunnel (StateT s) r)) -> StateT s m r Source #

MonadTransUnlift (StateT s) Source #

Instance details

Methods

liftWithUnlift :: MonadIO m => (Unlift MonadTunnelIO (StateT s) -> m r) -> StateT s m r Source #

getDiscardingUnlift :: forall (m :: Type -> Type). Monad m => StateT s m (WUnlift MonadTunnelIO (StateT s)) Source #

TransConstraint (MonadCatch e) (StateT s) Source #

Instance details

Methods

hasTransConstraint :: forall (m :: Type -> Type). MonadCatch e m => Dict (MonadCatch e (StateT s m)) Source #

TransConstraint (MonadThrow e) (StateT s) Source #

Instance details

Methods

hasTransConstraint :: forall (m :: Type -> Type). MonadThrow e m => Dict (MonadThrow e (StateT s m)) Source #

MonadException m => MonadException (StateT s m) Source #

Instance details

Associated Types

type Exc (StateT s m)
Instance details Defined in Control.Monad.Ology.Specific.StateT type Exc (StateT s m) = Exc m

Methods

throwExc :: Exc (StateT s m) -> StateT s m a Source #

catchExc :: StateT s m a -> (Exc (StateT s m) -> StateT s m a) -> StateT s m a Source #