Struct WriterTF 

pub struct WriterTF<W, M>(/* private fields */);

WriterT monad transformer: adds log accumulation to an inner monad.

WriterTF<W, M>::Of<A> = M::Of<(A, W)>

The log type W must be a Monoid (for pure/lift) and a Semigroup (for chain, which combines logs). This is the strict (non-lazy) variant.

Trait Implementations

impl<W, M> ApplicativeSt for WriterTF<W, M>

where W: Monoid + 'static, M: ApplicativeSt,

fn pure_st<A>(a: A) -> <M as HKT>::Of<(A, W)>

where A: 'static,

impl<W, M> ChainSt for WriterTF<W, M>

where W: Semigroup + Clone + 'static, M: ChainSt + FunctorSt,

fn chain_st<A, B>( fa: <M as HKT>::Of<(A, W)>, f: impl Fn(A) -> <M as HKT>::Of<(B, W)> + 'static, ) -> <M as HKT>::Of<(B, W)>

where A: 'static, B: 'static,

impl<W, M> FunctorSt for WriterTF<W, M>

where W: 'static, M: FunctorSt,

fn fmap_st<A, B>( fa: <M as HKT>::Of<(A, W)>, f: impl Fn(A) -> B + 'static, ) -> <M as HKT>::Of<(B, W)>

where A: 'static, B: 'static,

impl<W, M> HKT for WriterTF<W, M>

where W: 'static, M: HKT,

type Of<A> = <M as HKT>::Of<(A, W)>

impl<W, M> MonadTrans<M> for WriterTF<W, M>

where W: Monoid + 'static, M: FunctorSt,

fn lift<A>(ma: <M as HKT>::Of<A>) -> <M as HKT>::Of<(A, W)>

where A: 'static,

Lift an inner monadic value into the transformer.