Data.StateVar.Trans

Data.StateVarがIO専用なのが気にくわないので変換できるようにしただけ

Readable State Variables

class HasGetter g m | g -> m where

The class of all readable state variables.

Methods

get :: g a -> m a

Read the value of a state variable.

Instances

HasGetter TVar STM

HasGetter IORef IO

HasGetter (StateVar m) m

HasGetter (GettableStateVar m) m

HasGetter (STRef s) (ST s)

data GettableStateVar m a

A concrete implementation of a read-only state variable, carrying an IO action to read the value.

Instances

HasGetter (GettableStateVar m) m

makeGettableStateVar :: m a -> GettableStateVar m a

Construct a GettableStateVar from an IO action.

Writable State Variables

class HasSetter s m where

The class of all writable state variables.

Methods

($=) :: s a -> a -> m () infixr 2

Write a new value into a state variable.

Instances

HasSetter TVar STM

HasSetter IORef IO

HasSetter (StateVar m) m

HasSetter (SettableStateVar m) m

HasSetter (STRef s) (ST s)

data SettableStateVar m a

A concrete implementation of a write-only state variable, carrying an IO action to write the new value.

Instances

HasSetter (SettableStateVar m) m

makeSettableStateVar :: (a -> m ()) -> SettableStateVar m a

Construct a SettableStateVar from an IO action.

General State Variables

data StateVar m a

A concrete implementation of a readable and writable state variable, carrying one IO action to read the value and another IO action to write the new value.

Instances

HasSetter (StateVar m) m

HasGetter (StateVar m) m

makeStateVar :: m a -> (a -> m ()) -> StateVar m a

Construct a StateVar from two IO actions, one for reading and one for writing.

makePtrVar :: (MonadIO m, Storable a) => Ptr a -> StateVar m a

Utility Functions

($~) :: (Monad m, HasGetter v m, HasSetter v m) => v a -> (a -> a) -> m ()

A modificator convenience function, transforming the contents of a state variable with a given funtion.

($=!) :: (Monad m, HasSetter s m) => s a -> a -> m ()

A variant of $= which is strict in the value to be set.

($~!) :: (Monad m, HasGetter v m, HasSetter v m) => v a -> (a -> a) -> m ()

A variant of $~ which is strict in the transformed value.

(&) :: s -> (s -> t) -> t

(^=) :: HasSetter g m => (s -> g a) -> a -> s -> m () infixl 8

(^~) :: (Monad m, HasGetter g m, HasSetter g m) => (s -> g a) -> (a -> a) -> s -> m () infixl 8

(^=!) :: (Monad m, HasSetter g m) => (s -> g a) -> a -> s -> m () infixl 8

(^~!) :: (Monad m, HasGetter g m, HasSetter g m) => (s -> g a) -> (a -> a) -> s -> m () infixl 8

(^.) :: (Monad m, HasGetter g m, HasGetter h m) => (s -> g a) -> (a -> h b) -> s -> GettableStateVar m b infixl 8

(@=) :: (Monad m, MonadTrans n, MonadReader s (n m), HasSetter g m) => (s -> g a) -> a -> n m ()