Awesome
Monastic
A state monad implementation compliant to Fantasy Land inspired by fantasy-states.
$ npm install --save monastic
State
<a name="State" href="https://github.com/dicearr/monastic/blob/v3.0.3/index.js#L28">State :: (s -> {state :: s, value :: a}) -> State s a</a>
State type representative.
<a name="State.fantasy-land/of" href="https://github.com/dicearr/monastic/blob/v3.0.3/index.js#L36">State.fantasy-land/of :: a -> State s a</a>
Fantasy Land compliant implementation of Of.
> evalState (null) (Z.of (State, 1))
1
<a name="run" href="https://github.com/dicearr/monastic/blob/v3.0.3/index.js#L48">run :: s -> State s a -> {state :: s, value :: a}</a>
Evaluate a State instance with the given initial state and return both the internal state and value.
> run (1) (Z.of (State, 2))
{state: 1, value: 2}
<a name="modify" href="https://github.com/dicearr/monastic/blob/v3.0.3/index.js#L61">modify :: (s -> s) -> State s Null</a>
Creates a State instance which transforms its internal state using the
given transformation function, and has a value of null.
> execState (1) (modify (s => s + 1))
2
Modify can be used inside chain to get a new State instance with the internal state transformed.
> execState (null) (
. Z.chain (() => modify (s => s * 2), put (2))
. )
4
<a name="put" href="https://github.com/dicearr/monastic/blob/v3.0.3/index.js#L84">put :: s -> State s Null</a>
Creates a State instance which sets its internal state to the given value,
and has a value of null.
> execState (1) (put (2))
2
<a name="get" href="https://github.com/dicearr/monastic/blob/v3.0.3/index.js#L97">get :: State s s</a>
A State instance whose value is its internal state.
> evalState () (
. Z.chain (() => get, put (1))
. )
1
<a name="evalState" href="https://github.com/dicearr/monastic/blob/v3.0.3/index.js#L109">evalState :: s -> State s a -> a</a>
Evaluate a State instance with the given initial state and return the final value, discarding the final state.
> evalState () (Z.of (State, 1))
1
<a name="execState" href="https://github.com/dicearr/monastic/blob/v3.0.3/index.js#L122">execState :: s -> State s a -> s</a>
Evaluate a State instance with the given initial state and return the final state, discarding the final value.
> execState () (put (1))
1
<a name="State.fantasy-land/chainRec" href="https://github.com/dicearr/monastic/blob/v3.0.3/index.js#L135">State.fantasy-land/chainRec :: ((a -> c, b -> c, v) -> State s c, v) -> State s b</a>
Fantasy Land compliant implementation of ChainRec.
> const f = (next, done, v) => Z.of (State, v > 10 ? done (v) : next (v + 1))
> evalState (null) (Z.chainRec (State, f, 1))
11
<a name="State.prototype.fantasy-land/chain" href="https://github.com/dicearr/monastic/blob/v3.0.3/index.js#L156">State.prototype.fantasy-land/chain :: State s a ~> (a -> State s b) -> State s b</a>
Fantasy Land compliant implementation of Chain.
> evalState (null) (
. Z.chain (v => Z.of (State, v + 1), Z.of (State, 1))
. )
2
<a name="State.prototype.fantasy-land/map" href="https://github.com/dicearr/monastic/blob/v3.0.3/index.js#L173">State.prototype.fantasy-land/map :: State s a ~> (a -> b) -> State s b</a>
Fantasy Land compliant implementation of Map.
> evalState (null) (
. Z.map (x => x + 1, Z.of (State, 1))
. )
2
<a name="State.prototype.fantasy-land/ap" href="https://github.com/dicearr/monastic/blob/v3.0.3/index.js#L187">State.prototype.fantasy-land/ap :: State s a ~> State s (a -> b) -> State s b</a>
Fantasy Land compliant implementation of Ap.
> evalState (null) (
. Z.ap (Z.of (State, x => x + 1), Z.of (State, 1))
. )
2
<a name="StateT" href="https://github.com/dicearr/monastic/blob/v3.0.3/index.js#L205">StateT :: Monad m => m -> StateT s m a</a>
A state monad parametrised by the type m of the state to carry.
> import Maybe from 'sanctuary-maybe'
> const StateMaybe = StateT (Maybe)
> StateMaybe.evalState () (Z.of (StateMaybe, 42))
Z.of (Maybe, 42)
StateT
<a name="StateT(m).run" href="https://github.com/dicearr/monastic/blob/v3.0.3/index.js#L225">StateT(m).run :: s -> StateT s m a -> m s a</a>
Evaluate a StateT(m) instance with the given initial state and return both the internal state and value wrapped in a monad.
> run (1) (Z.of (StateMaybe, 2))
Z.of (Maybe, {state: 1, value: 2})
<a name="StateT(m).fantasy-land/of" href="https://github.com/dicearr/monastic/blob/v3.0.3/index.js#L236">StateT(m).fantasy-land/of :: Monad m => a -> StateT s m a</a>
Fantasy Land compliant implementation of Of.
> StateMaybe.evalState (null) (Z.of (StateMaybe, 1))
Z.of (Maybe, 1)
<a name="StateT(m).modify" href="https://github.com/dicearr/monastic/blob/v3.0.3/index.js#L248">StateT(m).modify :: Monad m => (s -> s) -> StateT s m Null</a>
Creates a StateT(m) instance which transforms its internal state using
the given transformation function, and has a value of null.
> StateMaybe.execState (2) (StateMaybe.modify (x => x + 1))
Z.of (Maybe, 3)
<a name="StateT(m).put" href="https://github.com/dicearr/monastic/blob/v3.0.3/index.js#L261">StateT(m).put :: Monad m => s -> StateT s m Null</a>
Creates a StateT(m) instance which sets its internal state to the given
value, and has a value of null.
> StateMaybe.execState (1) (StateMaybe.put (2))
Z.of (Maybe, 2)
<a name="StateT(m).get" href="https://github.com/dicearr/monastic/blob/v3.0.3/index.js#L274">StateT(m).get :: Monad m => StateT s m s</a>
A StateT(m) instance whose value is its internal state.
> run () (
. Z.chain (() => StateMaybe.get, StateMaybe.put (1))
. )
Z.of (Maybe, {state: 1, value: 1})
<a name="StateT(m).evalState" href="https://github.com/dicearr/monastic/blob/v3.0.3/index.js#L286">StateT(m).evalState :: Monad m => s -> StateT s m a -> m a</a>
Evaluate a StateT(m) instance with the given initial state and return the final value wrapped in a monad, discarding the final state.
> StateMaybe.evalState () (Z.of (StateMaybe, 1))
Z.of (Maybe, 1)
<a name="StateT(m).execState" href="https://github.com/dicearr/monastic/blob/v3.0.3/index.js#L299">StateT(m).execState :: Monad m => s -> StateT s m a -> m s</a>
Evaluate a StateT(m) instance with the given initial state and return the final state wrapped in a monad, discarding the final value.
> StateMaybe.execState () (StateMaybe.put (1))
Z.of (Maybe, 1)
<a name="StateT(m).lift" href="https://github.com/dicearr/monastic/blob/v3.0.3/index.js#L312">StateT(m).lift :: Monad m => Monad b -> StateT s m b</a>
Creates a StateT(m) instance and sets its value to the value wrapped in the given Monad.
> StateMaybe.evalState () (
. StateMaybe.lift (Z.of (Maybe, 1))
. )
Z.of (Maybe, 1)
<a name="StateT(m).fantasy-land/chainRec" href="https://github.com/dicearr/monastic/blob/v3.0.3/index.js#L329">StateT(m).fantasy-land/chainRec :: ((a -> c, b -> c, v) -> State s m c, v) -> State s m b</a>
Fantasy Land compliant implementation of ChainRec.
> const recf = (next, done, v) =>
. Z.of (StateMaybe, v > 10 ? done (v) : next (v + 1));
> StateMaybe.evalState (null) (
. Z.chainRec (StateMaybe, recf, 1)
. )
Z.of (Maybe, 11)
<a name="StateT(m).hoist" href="https://github.com/dicearr/monastic/blob/v3.0.3/index.js#L354">StateT(m).hoist :: Monad m => StateT s m a -> (m a -> m b) -> StateT s m b</a>
Creates a StateT(m) instance which transforms its internal value using the given transformation function.
> StateMaybe.evalState (null) (
. StateMaybe.hoist (Z.of (StateMaybe, 1)) (x => Z.map (v => v + 1, x))
. )
Z.of (Maybe, 2)
<a name="StateT(m).prototype.fantasy-land/chain" href="https://github.com/dicearr/monastic/blob/v3.0.3/index.js#L374">StateT(m).prototype.fantasy-land/chain :: Monad m => StateT s m a ~> (a -> StateT s m b) -> StateT s m b</a>
Fantasy Land compliant implementation of Chain.
> StateMaybe.evalState (null) (
. Z.chain (v => Z.of (StateMaybe, v + 1), Z.of (StateMaybe, 1))
. )
Z.of (Maybe, 2)
<a name="StateT(m).prototype.fantasy-land/map" href="https://github.com/dicearr/monastic/blob/v3.0.3/index.js#L391">StateT(m).prototype.fantasy-land/map :: Monad m => StateT s m a ~> (a -> b) -> StateT s m b</a>
Fantasy Land compliant implementation of Map.
> StateMaybe.evalState (null) (
. Z.map (x => x + 1, Z.of (StateMaybe, 1))
. )
Z.of (Maybe, 2)
<a name="StateT(m).prototype.fantasy-land/ap" href="https://github.com/dicearr/monastic/blob/v3.0.3/index.js#L407">StateT(m).prototype.fantasy-land/ap :: Monad m => State s m a ~> State s m (a -> b) -> State s m b</a>
Fantasy Land compliant implementation of Ap.
> StateMaybe.evalState (null) (
. Z.ap (Z.of (StateMaybe, x => x + 1), Z.of (StateMaybe, 1))
. )
Z.of (Maybe, 2)