rescala.operator.ObserveBundle.scala Maven / Gradle / Ivy

Go to download
package rescala.operator

import rescala.core.{Base, CreationTicket, Derived, Disconnectable, DisconnectableImpl, Observation, ReSource}

trait ObserveBundle {

  trait ObserveInteract extends Observation {
    // if true, the observer will remove all of its inputs, which allows eventual collection
    def checkExceptionAndRemoval(): Boolean
  }

  /** observers are normale reactives that are configured by a function that converts the value of the input into an [[ObserveInteract]] */
  object Observe {
    def strong[T](
        dependency: ReSource,
        fireImmediately: Boolean
    )(fun: dependency.Value => ObserveInteract)(implicit ct: CreationTicket[dependency.State]): Disconnectable = {
      ct.create[Pulse[Nothing], Disconnectable with Derived.of[dependency.State]](
        Set(dependency),
        Pulse.NoChange,
        fireImmediately
      ) {
        state =>
          class Obs extends Base[dependency.State, Pulse[Nothing]](state, ct.rename) with Derived
              with DisconnectableImpl {

            override type State[V] = dependency.State[V]

            override protected[rescala] def commit(base: Obs.this.Value): Obs.this.Value = Pulse.NoChange

            override protected[rescala] def guardedReevaluate(dt: ReIn): Rout = {
              val v  = dt.collectStatic(dependency)
              val oi = fun(v)
              if (oi.checkExceptionAndRemoval()) dt.trackDependencies(Set.empty)
              else dt.withEffect(oi)
            }
          }
          new Obs
      }
    }

  }
}