Use Kotlin features

CHANGES.md

@@ -2,8 +2,8 @@
 
 ## [Unreleased]
 ### Changed
+- **BREAKING** Replace `RxJava Disposable` with `Kotlin Job`, and remove `rxjava` completely. ([#10](https://github.com/diffplug/durian-rx/pull/10))
 - Add strict nullability to RxBox and improve efficiency. ([#12](https://github.com/diffplug/durian-rx/pull/12))
-- Replace `RxJava Disposable` with `Kotlin Job`, and remove `rxjava` completely. ([#10](https://github.com/diffplug/durian-rx/pull/10))
 - Bump required java from 11 to 17. ([#9](https://github.com/diffplug/durian-rx/pull/9))
 
 ## [4.0.1] - 2022-12-20

src/main/java/com/diffplug/common/rx/GuardedExecutor.kt

@@ -22,7 +22,6 @@ import java.util.concurrent.Executor
 import java.util.function.Supplier
 import kotlinx.coroutines.Deferred
 import kotlinx.coroutines.Job
-import kotlinx.coroutines.SupervisorJob
 import kotlinx.coroutines.flow.Flow
 
 /**
@@ -33,12 +32,11 @@ import kotlinx.coroutines.flow.Flow
  */
 open class GuardedExecutor(val delegate: RxExecutor, val guard: Chit) : Executor, RxSubscriber {
 	override fun execute(command: Runnable) {
-		delegate.executor().execute(guard.guard(command))
+		delegate.executor.execute(guard.guard(command))
 	}
 
 	/** Creates a runnable which runs on this Executor iff the guard widget is not disposed. */
 	fun wrap(delegate: Runnable): Runnable {
-		Objects.requireNonNull(delegate)
 		return Runnable { execute(guard.guard(delegate)) }
 	}
 
@@ -48,7 +46,7 @@ open class GuardedExecutor(val delegate: RxExecutor, val guard: Chit) : Executor
 			guard.runWhenDisposed { job.cancel() }
 			job
 		} else {
-			SupervisorJob().apply { cancel() }
+			Rx.sentinelJob
 		}
 	}
 

src/main/java/com/diffplug/common/rx/RxExecutor.kt

@@ -33,16 +33,13 @@ import kotlinx.coroutines.flow.onCompletion
 import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.launch
 
-class RxExecutor
-internal constructor(private val executor: Executor, val dispatcher: CoroutineDispatcher) :
+class RxExecutor internal constructor(val executor: Executor, val dispatcher: CoroutineDispatcher) :
 		RxSubscriber {
 
 	interface Has : Executor {
 		val rxExecutor: RxExecutor
 	}
 
-	fun executor() = executor
-
 	override fun <T> subscribe(flow: Flow<T>, listener: RxListener<T>) {
 		subscribeDisposable(flow, listener)
 	}