Cats - Extension Methods For Future/Task Conversion

Rather than consistently wrapping entire function calls we could embed implicit classes within the org.http4s.util.Task implementation.

Something like

object task extends TaskFunctions {
  implicit class TaskToFutureConverter[A](task: Task[A]){
    def unsafeToFuture : Future[A] = unsafeTaskToFuture[A](task)
  }
  implicit class FutureToTaskConverter[A](future: => Future[A])(implicit ec: ExecutionContext) {
    def toTask : Task[A] = futureToTask(future)(ec)
  }
}

This would allow us to interact on the edge of blaze/http4s much easier. The only major question is if this is required, why isn’t it directly in fs2? However this would in the implementation of the writeEntityBody.

  def writeEntityBody(p: EntityBody): Task[Boolean] = {
    val writeBody : Task[Unit] = (p to writeSink).run
    val writeBodyEnd : Task[Boolean] = writeEnd(Chunk.empty).toTask
    writeBody >> writeBodyEnd
  }
  
  private val writeSink: Sink[Task, Byte] = { s =>
    val writeStream : Stream[Task, Unit] = s.chunks.evalMap[Task, Task, Unit](writeBodyChunk(_ , false).toTask)
    val errorStream : Throwable => Stream[Task, Unit] = e => Stream.eval(exceptionFlush().toTask).flatMap{_ => fail(e)}
    writeStream.onError(errorStream)
  }

[ChristopherDavenport]

I would say that we can scratch that one, as it replaces the current implementation of unsafeTaskToFuture exactly, and it is on Task.

Infact on further investigation, we may be able scrap this whole package in favor of unsafeRunAsyncFuture and Task.fromFuture which allows us to move the futures to the edge.

Probably important to wait for @rossabaker to chime in.

[ChristopherDavenport]

Closed By #916