Scala猫：如何将List [ValidatedNel [E，A]]转换为Ior [NonEmptyList [E]，List [A]]？

Question

I tried:

def convert[E, A](in: List[ValidatedNel[E, A]]): Ior[NonEmptyList[E], List[A]] =
    in.separate

I get:

could not find implicit value for parameter G: cats.Bifoldable[cats.data.ValidatedNel]
[error]     in.separate

I then tried something like this:

  def convert[E, A](in: List[ValidatedNel[E, A]]): Ior[NonEmptyList[E], List[A]] =
    in.traverse(_.toIor)

Now I got:

 could not find implicit value for evidence parameter of type cats.Applicative[G]
[error]     in.traverse(_.toIor)

Answer 1

如@Toxaris所述， -Ypartial-unification需要打开