Comparison of Rapture I/O JSON extraction using a for comprehension, and using Scala Async.

async.scala

import rapture.io._
import scala.async._
import Async._
import scala.concurrent._
import ExecutionContext.Implicits.global
import strategy.returnFutures
implicit val encoding = Encodings.`UTF-8`

val forStyle = for {
  src <- (Http / "rapture.io" / "example.json").slurp[Char]
  json <- Json.parse(src)
  first <- json.firstName.get[String]
  last <- json.lastName.get[String]
  home <- json.phoneNumber(0).number.get[String]
  entry <- Future(s"${last}, ${first}: ${home}")
} yield entry

val asyncStyle = async {
  val src = await((Http / "rapture.io" / "example.json").slurp[Char])
  val json = await(Json.parse(src))
  s"${await(json.lastName.get[String])}, ${await(json.firstName.get[String])}: ${await(json.phoneNumber(0).number.get[String])}"
}

println(forStyle.value)
println(asyncStyle.value)