Added main sus4s types

core/src/main/scala/in/rcard/sus4s/sus4s.scala

@@ -0,0 +1,45 @@
+package in.rcard.sus4s
+
+import java.util.concurrent.{CompletableFuture, StructuredTaskScope}
+
+object sus4s {
+ trait Suspend {
+ val scope: StructuredTaskScope[Any]
+ }
+
+ type Suspended[A] = Suspend ?=> A
+
+ class Job[A] private[sus4s] (private val cf: CompletableFuture[A]) {
+ def value: A = cf.join()
+ }
+
+ inline def structured[A](inline block: Suspend ?=> A): A = {
+ val _scope = new StructuredTaskScope.ShutdownOnFailure()
+
+ given suspended: Suspend = new Suspend {
+ override val scope: StructuredTaskScope[Any] = _scope
+ }
+
+ try {
+ val mainTask = _scope.fork(() => {
+ block
+ })
+ _scope.join().throwIfFailed(identity)
+ mainTask.get()
+ } finally {
+ _scope.close()
+ }
+ }
+
+ def fork[A](block: Suspend ?=> A): Suspend ?=> Job[A] = {
+ val result = new CompletableFuture[A]()
+ summon[Suspend].scope.fork(() => {
+ try result.complete(block)
+ catch
+ case throwable: Throwable =>
+ result.completeExceptionally(throwable)
+ throw throwable;
+ })
+ Job(result)
+ }
+}

core/src/test/scala/StructuredSpec.scala

@@ -0,0 +1,102 @@
+import in.rcard.sus4s.sus4s
+import in.rcard.sus4s.sus4s.{fork, structured}
+import org.scalatest.TryValues.*
+import org.scalatest.flatspec.AnyFlatSpec
+import org.scalatest.matchers.should.Matchers
+
+import java.util.concurrent.ConcurrentLinkedQueue
+import scala.util.Try
+
+class StructuredSpec extends AnyFlatSpec with Matchers {
+
+ "A structured program" should "wait the completion of all the forked jobs" in {
+ val results = structured {
+ val queue = new ConcurrentLinkedQueue[String]()
+ val job1 = fork {
+ Thread.sleep(1000)
+ queue.add("job1")
+ }
+ val job2 = fork {
+ Thread.sleep(500)
+ queue.add("job2")
+ }
+ val job3 = fork {
+ Thread.sleep(100)
+ queue.add("job3")
+ }
+ queue
+ }
+
+ results.toArray should contain theSameElementsInOrderAs List("job3", "job2", "job1")
+ }
+
+ it should "stop the execution if one the job throws an exception" in {
+ val results = new ConcurrentLinkedQueue[String]()
+ val tryResult = Try {
+ structured {
+ val job1 = fork {
+ Thread.sleep(1000)
+ results.add("job1")
+ }
+ val job2 = fork {
+ Thread.sleep(500)
+ results.add("job2")
+ throw new RuntimeException("Error")
+ }
+ val job3 = fork {
+ Thread.sleep(100)
+ results.add("job3")
+ }
+ }
+ }
+
+ tryResult.failure.exception shouldBe a[RuntimeException]
+ tryResult.failure.exception.getMessage shouldBe "Error"
+ results.toArray should contain theSameElementsInOrderAs List("job3", "job2")
+ }
+
+ it should "stop the execution if the block throws an exception" in {
+ val results = new ConcurrentLinkedQueue[String]()
+ val tryResult = Try {
+ structured {
+ val job1 = fork {
+ Thread.sleep(1000)
+ results.add("job1")
+ }
+ val job2 = fork {
+ Thread.sleep(500)
+ results.add("job2")
+ }
+ val job3 = fork {
+ Thread.sleep(100)
+ results.add("job3")
+ }
+ throw new RuntimeException("Error")
+ }
+ }
+
+ tryResult.failure.exception shouldBe a[RuntimeException]
+ tryResult.failure.exception.getMessage shouldBe "Error"
+ results.toArray shouldBe empty
+ }
+
+ it should "join the values of different jobs" in {
+ val queue = new ConcurrentLinkedQueue[String]()
+ val result = structured {
+ val job1 = fork {
+ Thread.sleep(1000)
+ queue.add("job1")
+ 42
+ }
+ val job2 = fork {
+ Thread.sleep(500)
+ queue.add("job2")
+ 43
+ }
+ job1.value + job2.value
+ }
+
+ queue.toArray should contain theSameElementsInOrderAs List("job2", "job1")
+ result shouldBe 85
+ }
+}