task

A Task can be created from for-comprehension, where keywords.Each and keywords.Fork can be used together to asynchronously iterate collections. For example, the above concatenateRemoteData downloads and concatenates data from multiple URLs.

        import com.thoughtworks.dsl.bangnotation._
        import com.thoughtworks.dsl._
        import com.thoughtworks.dsl.keywords._
        import com.thoughtworks.dsl.keywords.Shift._
        import com.thoughtworks.dsl.domains.task.Task
        import java.net.URL
        def concatenateRemoteData(urls: List[URL], downloader: URL => Task[Vector[Byte]]): Task[Vector[Byte]] = {
          for {
            url <- Fork(urls)
            data <- Shift(downloader(url))
            byte <- Each(data)
          } yield byte
        }.as[Task[Vector[Byte]]]

    A [[Task]] can be also created from [[Task.apply]]

        def mockDownloader(url: URL) = Task {
          "mock data\n".getBytes.toVector
        }

    A [[Task]] can be then converted to [[scala.concurrent.Future]] via [[Task.toFuture]],
    in order to integrate into other frameworks.
    In this example, it's a `Future[Assertion]` required by [[org.scalatest.freespec.AsyncFreeSpec]].

        val mockUrls = List(new URL("http://example.com/file1"), new URL("http://example.com/file2"))
        import org.scalatest.Assertion
        def assertion: Task[Assertion] = *[Task] {
          !Shift(concatenateRemoteData(mockUrls, mockDownloader)) should be("mock data\nmock data\n".getBytes.toVector)
        }
        Task.toFuture(assertion)