kciter

const reduce = (f) => (acc, iter) => {
  if (!iter) acc = (iter = acc[Symbol.iterator]()).next().value;
  for (const a of iter) acc = f(acc, a);
  return acc;
}

const go = (arg, ...fs) => reduce((arg, f) => f(arg))(arg, fs);

const Pair = (left, right) => (destructurePair) => destructurePair(left, right);

kciter

import kotlin.contracts.ExperimentalContracts
import kotlin.contracts.InvocationKind
import kotlin.contracts.contract

@OptIn(ExperimentalContracts::class)
inline fun <V, E: Throwable> binding(crossinline block: BindingScope<E>.() -> V): Effect<V, E> {
  contract {
    callsInPlace(block, InvocationKind.EXACTLY_ONCE)
  }