Examples

Chain two pipelines

Simple UNIX-pipe style chaining of two pipelines:

import etl4s._

val p1 = Pipeline((i: Int) => i.toString)
val p2 = Pipeline((s: String) => s + "!")

val p3: Pipeline[Int, String] = p1 ~> p2

Complex chaining

Connect the output of two pipelines to a third:

import etl4s._

val namePipeline = Pipeline("John Doe")
val agePipeline  = Pipeline(30)
val toUpper      = Transform[String, String](_.toUpperCase)
val consoleLoad  = Load[String, Unit](println(_))

val combined: Pipeline[Unit, Unit] =
  for {
    name <- namePipeline
    age <- agePipeline
    _ <- Extract(s"$name | $age") ~> toUpper ~> consoleLoad
  } yield ()