FT algebra key-value

trait KVStore[F[_], K, V] {
  def get(key: K): F[Option[V]]
  def put(key: K, value: V): F[Unit]
}

class Dict[F[_]: Monad, K, V](store: KVStore[F, K, V]) {
  def computeIfAbsent(k: K, absent: => V)(implicit m: Monad[F]): F[V] = {
    m.flatMap(store.get(k)) { value =>
      m.pure(value.getOrElse(absent))
    }
  }
}