Struct StateTF 

pub struct StateTF<S, M>(/* private fields */);

StateT monad transformer: adds mutable state to an inner monad.

StateTF<S, M>::Of<A> = Box<dyn Fn(S) -> M::Of<(S, A)>>

Unlike ReaderT, the state is threaded (modified) through computations. When the inner monad is IdentityF, this is equivalent to the State monad from karpal-core’s adjunction module.

Trait Implementations

impl<S: Clone + 'static, M: ChainSt + 'static> ChainSt for StateTF<S, M>

fn chain_st<A: 'static, B: 'static>( fa: Box<dyn Fn(S) -> M::Of<(S, A)>>, f: impl Fn(A) -> Box<dyn Fn(S) -> M::Of<(S, B)>> + 'static, ) -> Box<dyn Fn(S) -> M::Of<(S, B)>>

impl<S: 'static, M: FunctorSt + 'static> FunctorSt for StateTF<S, M>

fn fmap_st<A: 'static, B: 'static>( fa: Box<dyn Fn(S) -> M::Of<(S, A)>>, f: impl Fn(A) -> B + 'static, ) -> Box<dyn Fn(S) -> M::Of<(S, B)>>

impl<S: 'static, M: HKT + 'static> HKT for StateTF<S, M>

type Of<A> = Box<dyn Fn(S) -> <M as HKT>::Of<(S, A)>>

impl<S: Clone + 'static, M: FunctorSt + 'static> MonadTrans<M> for StateTF<S, M>

fn lift<A: 'static>(ma: M::Of<A>) -> Box<dyn Fn(S) -> M::Of<(S, A)>>

where M::Of<A>: Clone,

Lift an inner monadic value into the transformer.