| Safe Haskell | Safe-Inferred |
|---|
Control.Monad.State.View
Contents
Description
A module extending the functionality of the State Monad with Views
- module Control.Monad.State
- module Data.View
- viewState :: MonadState s m => View s t -> (t -> (a, t)) -> m a
- viewing :: MonadState s m => View s t -> State t a -> m a
- modifying :: MonadState s m => View s t -> (t -> t) -> m ()
- getting :: MonadState s m => View s a -> m a
- putting :: MonadState s m => View s t -> t -> m ()
- swappingWith :: MonadState s m => View s t -> (t -> t) -> m b -> m b
- swapping :: MonadState s m => View s t -> t -> m b -> m b
- saving :: MonadState s m => View s t -> m b -> m b
Documentation
module Control.Monad.State
module Data.View
Views with State
viewState :: MonadState s m => View s t -> (t -> (a, t)) -> m aSource
Constructs a State monad that acts on a View.
viewing :: MonadState s m => View s t -> State t a -> m aSource
Executes a state restricted to the given View.
modifying :: MonadState s m => View s t -> (t -> t) -> m ()Source
Modifies the view by the given function. modifying v f is equivalent to viewing v (modify f).
getting :: MonadState s m => View s a -> m aSource
Gets the given view from the whole state
putting :: MonadState s m => View s t -> t -> m ()Source
Injects the given value into the whole state. putting v x is equivalent to viewing v (put x).
swappingWith :: MonadState s m => View s t -> (t -> t) -> m b -> m bSource
swappingWith v f m executes m in an environment where the view v was modified by f,
preserving the old value of v (it swaps the old value and the new, and then swaps back after m)
swapping :: MonadState s m => View s t -> t -> m b -> m bSource
A special case of swappingWith with a constant value.
saving :: MonadState s m => View s t -> m b -> m bSource
saving v m executes m, while preserving the value of the View v.