/*
 * Copyright (C) 2007-2016 Artima, Inc. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * Automatically generated Scala interpreter transcript from:
 *
 * Programming in Scala (Third Edition)
 * by Martin Odersky, Lex Spoon, Bill Venners
 *
 * http://booksites.artima.com/programming_in_scala_3ed
 */


scala> import scala.concurrent.Future
import scala.concurrent.Future

scala> val fut = Future { Thread.sleep(10000); 21 + 21 }
<console>:8: error: Cannot find an implicit ExecutionContext. You might pass
an (implicit ec: ExecutionContext) parameter to your method
or import scala.concurrent.ExecutionContext.Implicits.global.
       val fut = Future { Thread.sleep(10000); 21 + 21 }
                        ^

scala> import scala.concurrent.ExecutionContext.Implicits.global
import scala.concurrent.ExecutionContext.Implicits.global

scala> val fut = Future { Thread.sleep(10000); 21 + 21 }
fut: scala.concurrent.Future[Int] = scala.concurrent.impl.Promise$DefaultPromise@2174e7c2

scala> fut.isCompleted
res0: Boolean = false

scala> fut.value
res1: Option[scala.util.Try[Int]] = None

scala> fut.isCompleted
res2: Boolean = false

scala> fut.value
res3: Option[scala.util.Try[Int]] = None

scala> val fut = Future { Thread.sleep(10000); 21 / 0 }
fut: scala.concurrent.Future[Int] = scala.concurrent.impl.Promise$DefaultPromise@453d36ad

scala> fut.value
res4: Option[scala.util.Try[Int]] = None

scala> fut.value
res5: Option[scala.util.Try[Int]] = None

scala> val fut = Future { Thread.sleep(10000); 21 + 21 }
fut: scala.concurrent.Future[Int] = scala.concurrent.impl.Promise$DefaultPromise@2cac2b2c

scala> val result = fut.map(x => x + 1)
result: scala.concurrent.Future[Int] = scala.concurrent.impl.Promise$DefaultPromise@6d3c6012

scala> result.value
res6: Option[scala.util.Try[Int]] = None

scala> for {

scala> res7.value
<console>:10: error: recursive value res7 needs type
              res7.value
              ^

scala> for {

scala> res9.value
<console>:10: error: not found: value res9
              res9.value
              ^

scala> // Will need at least 20 seconds to complete

scala> res9.value
<console>:10: error: not found: value res9
              res9.value
              ^

scala> val pro = Promise[Int]
<console>:9: error: not found: value Promise
       val pro = Promise[Int]
                 ^

scala> val fut = pro.future
<console>:9: error: not found: value pro
       val fut = pro.future
                 ^

scala> fut.value
res11: Option[scala.util.Try[Int]] = None

scala> pro.success(42)
<console>:10: error: not found: value pro
              pro.success(42)
              ^

scala> fut.value
res13: Option[scala.util.Try[Int]] = None

scala> val fut = Future { 42 }
fut: scala.concurrent.Future[Int] = scala.concurrent.impl.Promise$DefaultPromise@6b136442

scala> val valid = fut.filter(res => res > 0)
valid: scala.concurrent.Future[Int] = scala.concurrent.impl.Promise$DefaultPromise@5a44adf8

scala> valid.value
res14: Option[scala.util.Try[Int]] = Some(Success(42))

scala> val invalid = fut.filter(res => res < 0)
invalid: scala.concurrent.Future[Int] = scala.concurrent.impl.Promise$DefaultPromise@5d10686f

scala> invalid.value
res15: Option[scala.util.Try[Int]] = Some(Failure(java.util.NoSuchElementException: Future.filter predicate is not satisfied))

scala> val valid = for (res <- fut if res > 0) yield res
valid: scala.concurrent.Future[Int] = scala.concurrent.impl.Promise$DefaultPromise@6a81c750

scala> valid.value
res16: Option[scala.util.Try[Int]] = Some(Success(42))

scala> val invalid = for (res <- fut if res < 0) yield res
invalid: scala.concurrent.Future[Int] = scala.concurrent.impl.Promise$DefaultPromise@17b4b780

scala> invalid.value
res17: Option[scala.util.Try[Int]] = Some(Failure(java.util.NoSuchElementException: Future.filter predicate is not satisfied))

scala> val valid =

scala> valid.value
res18: Option[scala.util.Try[Int]] = Some(Success(42))

scala> val invalid =

scala> invalid.value
res19: Option[scala.util.Try[Int]] = Some(Failure(java.util.NoSuchElementException: Future.filter predicate is not satisfied))

scala> val failure = Future { 42 / 0 }
failure: scala.concurrent.Future[Int] = scala.concurrent.impl.Promise$DefaultPromise@7d42a64e

scala> failure.value
res20: Option[scala.util.Try[Int]] = Some(Failure(java.lang.ArithmeticException: / by zero))

scala> val expectedFailure = failure.failed
expectedFailure: scala.concurrent.Future[Throwable] = scala.concurrent.impl.Promise$DefaultPromise@59f7817e

scala> expectedFailure.value
res21: Option[scala.util.Try[Throwable]] = Some(Success(java.lang.ArithmeticException: / by zero))

scala> val success = Future { 42 / 1 }
success: scala.concurrent.Future[Int] = scala.concurrent.impl.Promise$DefaultPromise@632ac433

scala> success.value
res22: Option[scala.util.Try[Int]] = Some(Success(42))

scala> val unexpectedSuccess = success.failed
unexpectedSuccess: scala.concurrent.Future[Throwable] = scala.concurrent.impl.Promise$DefaultPromise@5e4da34e

scala> unexpectedSuccess.value
res23: Option[scala.util.Try[Throwable]] = Some(Failure(java.util.NoSuchElementException: Future.failed not completed with a throwable.))

scala> val fallback = failure.fallbackTo(success)
fallback: scala.concurrent.Future[Int] = scala.concurrent.impl.Promise$DefaultPromise@39dae9ba

scala> fallback.value
res24: Option[scala.util.Try[Int]] = Some(Success(42))

scala> val failedFallback = failure.fallbackTo(

scala> failedFallback.value
<console>:10: error: not found: value failedFallback
              failedFallback.value
              ^

scala> val recovered = failedFallback recover {

scala> recovered.value
<console>:10: error: not found: value recovered
              recovered.value
              ^

scala> val unrecovered = fallback recover {

scala> unrecovered.value
<console>:10: error: not found: value unrecovered
              unrecovered.value
              ^

scala> val alsoUnrecovered = failedFallback recover {

scala> alsoUnrecovered.value
<console>:10: error: not found: value alsoUnrecovered
              alsoUnrecovered.value
              ^

scala> val alsoRecovered = failedFallback recoverWith {

scala> alsoRecovered.value
<console>:10: error: not found: value alsoRecovered
              alsoRecovered.value
              ^

scala> val first = success.transform(

scala> first.value
<console>:10: error: not found: value first
              first.value
              ^

scala> val second = failure.transform(

scala> second.value
<console>:10: error: not found: value second
              second.value
              ^

scala> val firstCase = success.transform { // Scala 2.12

scala> firstCase.value
<console>:10: error: not found: value firstCase
              firstCase.value
              ^

scala> val secondCase = failure.transform {

scala> secondCase.value
<console>:10: error: not found: value secondCase
              secondCase.value
              ^

scala> val nonNegative = failure.transform { // Scala 2.12

scala> nonNegative.value
<console>:10: error: not found: value nonNegative
              nonNegative.value
              ^

scala> val zippedSuccess = success zip recovered
<console>:10: error: not found: value recovered
       val zippedSuccess = success zip recovered
                                       ^

scala> zippedSuccess.value
<console>:10: error: not found: value zippedSuccess
              zippedSuccess.value
              ^

scala> val zippedFailure = success zip failure
zippedFailure: scala.concurrent.Future[(Int, Int)] = scala.concurrent.impl.Promise$DefaultPromise@5b99719b

scala> zippedFailure.value
res36: Option[scala.util.Try[(Int, Int)]] = Some(Failure(java.lang.ArithmeticException: / by zero))

scala> val fortyTwo = Future { 21 + 21 }
fortyTwo: scala.concurrent.Future[Int] = scala.concurrent.impl.Promise$DefaultPromise@49ea52ee

scala> val fortySix = Future { 23 + 23 }
fortySix: scala.concurrent.Future[Int] = scala.concurrent.impl.Promise$DefaultPromise@5b9fa3b0

scala> val futureNums = List(fortyTwo, fortySix)
futureNums: List[scala.concurrent.Future[Int]] = List(scala.concurrent.impl.Promise$DefaultPromise@49ea52ee, scala.concurrent.impl.Promise$DefaultPromise@5b9fa3b0)

scala> val folded =

scala> folded.value
<console>:10: error: not found: value folded
              folded.value
              ^

scala> val reduced =

scala> reduced.value
<console>:10: error: not found: value reduced
              reduced.value
              ^

scala> val futureList = Future.sequence(futureNums)
futureList: scala.concurrent.Future[List[Int]] = scala.concurrent.impl.Promise$DefaultPromise@307587c

scala> futureList.value
res39: Option[scala.util.Try[List[Int]]] = Some(Success(List(42, 46)))

scala> val traversed =

scala> traversed.value
<console>:10: error: not found: value traversed
              traversed.value
              ^

scala> failure.foreach(ex => println(ex))

scala> success.foreach(res => println(res))
42

scala> for (res <- failure) println(res)

scala> for (res <- success) println(res)
42

scala> import scala.util.{Success, Failure}
import scala.util.{Success, Failure}

scala> success onComplete {

scala> failure onComplete {

scala> val newFuture = success andThen {

scala> newFuture.value
<console>:11: error: not found: value newFuture
              newFuture.value
              ^

scala> import scala.concurrent.Await
import scala.concurrent.Await

scala> import scala.concurrent.duration._
import scala.concurrent.duration._

scala> val fut = Future { Thread.sleep(10000); 21 + 21 }
fut: scala.concurrent.Future[Int] = scala.concurrent.impl.Promise$DefaultPromise@7fa21479

scala> val x = Await.result(fut, 15.seconds) // blocks
x: Int = 42

scala> import org.scalatest.Matchers._
<console>:14: error: object scalatest is not a member of package org
       import org.scalatest.Matchers._
                  ^

scala> x should be (42)
<console>:17: error: value should is not a member of Int
              x should be (42)
                ^
<console>:17: error: not found: value be
              x should be (42)
                       ^

scala> import org.scalatest.concurrent.ScalaFutures._
<console>:14: error: object scalatest is not a member of package org
       import org.scalatest.concurrent.ScalaFutures._
                  ^

scala> val fut = Future { Thread.sleep(10000); 21 + 21 }
fut: scala.concurrent.Future[Int] = scala.concurrent.impl.Promise$DefaultPromise@381836f5

scala> fut.futureValue should be (42) // futureValue blocks
<console>:16: error: value futureValue is not a member of scala.concurrent.Future[Int]
              fut.futureValue should be (42) // futureValue blocks
                  ^
<console>:16: error: not found: value be
              fut.futureValue should be (42) // futureValue blocks
                                     ^

scala> NameResolver ! "EXIT"; Thread.sleep(500)
<console>:14: error: not found: value NameResolver
              NameResolver ! "EXIT";;
              ^