| Copyright | (C) Frank Staals |
|---|---|
| License | see the LICENSE file |
| Maintainer | Frank Staals |
| Safe Haskell | None |
| Language | Haskell2010 |
Control.Monad.State.Persistent
Description
Synopsis
- data PersistentStateT s m a
- type PersistentState s = PersistentStateT s Identity
- store :: Monad m => PersistentStateT s m ()
- runPersistentStateT :: Functor m => PersistentStateT s m a -> s -> m (a, s, [s])
- runPersistentState :: PersistentState s a -> s -> (a, s, [s])
Documentation
data PersistentStateT s m a Source #
A State monad that can store earlier versions of the state.
Instances
type PersistentState s = PersistentStateT s Identity Source #
A State monad that can store earlier versions of the state.
store :: Monad m => PersistentStateT s m () Source #
Create a snapshot of the current state and add it to the list of states that we store.
runPersistentStateT :: Functor m => PersistentStateT s m a -> s -> m (a, s, [s]) Source #
Run a persistentStateT, returns a triplet with the value, the last state and a list of all states (including the last one) in chronological order
runPersistentState :: PersistentState s a -> s -> (a, s, [s]) Source #
Run a persistentStateT, returns a triplet with the value, the last state and a list of all states (including the last one) in chronological order