EmitterBuilder to create IO[R]

[cornerman]

I was just trying to create a custom EmitterBuilder for some modifier combiniation, but was not able to model this properly. When creating a SimpleEmitterBuilder[E,R], I can provide a create function Observer[E] => R, whose result is then wrapped with IO.pure.

In this case, I want to return an IO[R], which does not work as expected

  def valueOnEnter: SimpleEmitterBuilder[String, VDomModifier] = SimpleEmitterBuilder { (observer: Observer[String]) =>
    for {
      userInput <- Handler.create[String]
      actionSink = ObserverSink(observer)
      modifiers <- Seq(
        managed(actionSink <-- userInput),
        ...
        onKeyDown.value --> actionSink
      )
    } yield modifiers
  }

Now def -->(sink: Sink[_ >: E]): IO[R] = IO.pure(create(sink.observer)) will yield an IO[IO[Modifier]], which is not really usable.

Any ideas how to use this? Or should we make a version with IO[R]?

Additionally, having a Sink instead of an observer would be preferable.