Documentation

modifyM :: (Monad m, MonadTrans t, MonadState a (t m)) => (a -> m a) -> t m ()Source

Like modify, except use Monad wrap update function.

modifyM_ :: (Monad m, MonadTrans t, MonadState a1 (t m)) => (a1 -> m a) -> (a -> a1) -> (a -> a2) -> t m a2Source

Like modifyM, but add two functions filter new state and return value. This is handy when function return result including state. Example, state is (a,b), and function return (a,b,c), then you can write: result <- modifyM_ f fst snd.

modifyM' :: (Monad m, MonadTrans t, MonadState a1 (t m)) => (a1 -> m a) -> (a -> a1) -> t m ()Source

Like modifyM_, except don't return value.

modifyFst :: MonadState (t, t1) m => ((t, t1) -> t) -> m ()Source

Modify fst state of tuple.

modifySnd :: MonadState (t, t1) m => ((t, t1) -> t1) -> m ()Source

Modify snd state of tuple.

modifyFstM :: (Monad m, MonadTrans t1, MonadState (a, t) (t1 m)) => ((a, t) -> m a) -> t1 m ()Source

Like modifyFst, except use moand wrap function.

modifySndM :: (Monad m, MonadTrans t1, MonadState (t, a) (t1 m)) => ((t, a) -> m a) -> t1 m ()Source

Like modifySnd, except use moand wrap function.

getM :: (MonadState a (t m), MonadTrans t, Monad m) => (a -> m a1) -> t m a1Source

Like get, except use Monad wrap function.

runStateT_ :: b -> StateT b m a -> m (a, b)Source

Like runStateT, just reverse arguments order.

runStateT' :: Functor f => b -> StateT b f a -> f bSource

Like runStateT_, but just return last argument. It's useful that you just want use runStateT wrap *one* state.

runTVarStateT :: TVar a -> (a -> StateT a IO b) -> IO ()Source

Use runStateT' wrap TVar.

runTVarTupeStateT :: (TVar a, TVar b) -> (a -> b -> StateT (a, b) IO c) -> IO ()Source

Like runTVarStateT, but handle tuple TVar.