teststate.run.Observer.scala Maven / Gradle / Ivy
package teststate.run
import teststate.data.{Or, Right}
final class Observer[-R, +O, +E](val observe: R => E Or O) extends AnyVal {
@inline def apply(r: R) = observe(r)
def cmapR[RR](f: RR => R): Observer[RR, O, E] =
new Observer(observe compose f)
def pmapR[RR, EE >: E](f: RR => EE Or R): Observer[RR, O, EE] =
new Observer(r => f(r) flatMap observe)
def mapO[OO](f: O => OO): Observer[R, OO, E] =
new Observer(observe(_) map f)
def mapE[EE](f: E => EE): Observer[R, O, EE] =
new Observer(observe(_) leftMap f)
}
object Observer {
def apply[R, O](f: R => O): Observer[R, O, Nothing] =
new Observer(r => Right(f(r)))
def attempt[R, O, E](f: R => E Or O): Observer[R, O, E] =
new Observer(f)
def watch[O](obs: => O): Observer[Any, O, Nothing] =
new Observer(_ => Right(obs))
def watchTry[O, E](obs: => E Or O): Observer[Any, O, E] =
new Observer(_ => obs)
def unit: Observer[Any, Unit, Nothing] =
watch(())
}