add

Traverse#traverse

Traverse<F>

Applicative<G>

traverse

fun <G, A, B> Kind<F, A>.traverse(AP: Applicative<G>, f: (A) -> Kind<G, B>): Kind<G, Kind<F, B>>

fun <G, A, B> Kind<F, A>.traverse(f: (A) -> Kind<G, B>, with Applicative<G>): Kind<G, Kind<F, B>>

listOf(Option(1), Option(2)).traverse(::identity, Option.applicative())

import OptionApplicative

listOf(Option(1), Option(2)).traverse(::identity)

with

with

with

varargs

with

with

with($ev1) { ... }

with

fun <A, B> withEvidence(f: A.() -> B) : B = f($evA)

fun <A, B> fmap(f: (A) -> B, Fa: Kind<F, A> with Functor<F>): Kind<F, B>...

fun <F, G, A, B> foo(f: (A) -> B, Fa: Kind<F, A>): Kind<G, B>

fun <A, B> Kind<F, A>.fmap(f: (A) -> B, with Functor<F>): Kind<F, B>

fun <F, G, A, B> Kind<F, A>.foo(f: (A) -> B, with WhateverConstrain<G>): Kind<G, B>

fun User.saveAndLog(with UserRepository, SystemLogger) = 
  log(user.save())

interface Repository<A> {
  fun A.save(): A
}

extension object UserRepository : Repository<User> {
   fun User.save(): User = TODO()
}