env_simple_abstract.scala

private final class EnvCtx[Ctx, +A] (zio: RIO[Ctx, A]) extends Env[Ctx, A] {
  override def run: RIO[Ctx, A] = zio
  override def map[B](f: A => B) = ... 
  override def flatMap[B](f: A => Env[Ctx, B]) = ...
  override def unsafeRunSync(env: Ctx): A = {
    Exit.fromZIOExit(runtime.unsafeRunSync(zio.provide(env))) match {
      case Exit.Success(value) => value
      case Exit.Error(throwable) => throw throwable
      case Exit.Termination(throwable) => throw throwable
    }
  }
}
object EnvCtx {
  def apply[R, A](body: => A): Env[R, A] = ofZIO(ZIO(body))
  def pure[R, A](x: A): Env[R, A] = ofZIO(ZIO.succeed(x))
  def delay[R, A](x: A): Env[R, A] = ofZIO(ZIO.effect(x))
  def ofZIO[R, A](zio: RIO[R, A]): Env[R, A] = EnvCtx(zio)
}