Decide about exposing full-blown split() operation

[ktoso]

As follow up to #17196 we now have SplitWhereProcessorImpl which is backing both splitWhen and splitAfter. It could also express arbitrary "split-like" operations. This ticket is about deciding if we want to expose it and if yes, with what API, maybe like:

object SplitDecision {
  sealed abstract class SplitDecision

  /** Splits before the current element. The current element will be the first element in the new substream. */
  case object SplitBefore extends SplitDecision

  /** Splits after the current element. The current element will be the last element in the current substream. */
  case object SplitAfter extends SplitDecision

  /** Drops the current element, completes the current substream. The next element will be emitted into a new substream. */
  case object SplitDrop extends SplitDecision

  /** Emit this element into the current substream. */
  case object Continue extends SplitDecision

  /** Drop this element without signalling it to any substream. */
  case object Drop extends SplitDecision
}

// ---------

def split(decide: Out => SplitDecision): Source[Source[U, Unit], Mat] = ???

TODO: There may have been discussions about this operation around the websocket tickets - dig them up.

[He-Pin]

nice