Kotlin lambda 语法混淆

I'm confused by Kotlin lambda syntax.

At first, I have

.subscribe(
          { println(it) }
          , { println(it.message) }
          , { println("completed") }
      )

which works fine美元.

然后我将onNext移动到另一个名为GroupRecycleServiceAdapter的类，该类实现了Action1<ArrayList<Group>>.

.subscribe(
          view.adapter as GroupRecyclerViewAdapter
          , { println(it.message) }
          , { println("completed") }
      )

However, I got the error:

Error:(42, 17) Type mismatch: inferred type is () -> ??? but rx.functions.Action1<kotlin.Throwable!>! was expected
Error:(42, 27) Unresolved reference: it
Error:(43, 17) Type mismatch: inferred type is () -> kotlin.Unit but rx.functions.Action0! was expected

I can fix the error by changing to:

.subscribe(
          view.adapter as GroupRecyclerViewAdapter
          , Action1<kotlin.Throwable> { println(it.message) }
          , Action0 { println("completed") }
      )

Is there a way to write the lambda without specifying a type? (Action1<kotlin.Throwable>, Action0)

Note: subscribe is RxJava method

Edit 1

class GroupRecyclerViewAdapter(private val groups: MutableList<Group>,
                           private val listener: OnListFragmentInteractionListener?) :
RecyclerView.Adapter<GroupRecyclerViewAdapter.ViewHolder>(), Action1<ArrayList<Group>> {