FutureとTryの共通メソッド #Scala

共通メソッド

(implicit executor: ExecutionContext) は省略

共通メソッド	Future	Try
`map`	`map[S](f: (T) ⇒ S): Future[S]`	`map[U](f: (T) ⇒ U): Try[U]`
`flatMap`	`flatMap[S](f: (T) ⇒ Future[S]): Future[S]`	`flatMap[U](f: (T) ⇒ Try[U]): Try[U]`
`foreach`	`foreach[U](f: (T) ⇒ U): Unit`	`foreach[U](f: (T) ⇒ U): Unit`
`failed`	`failed: Future[Throwable]`	`failed: Try[Throwable]`
`recover`	`recover[U >: T](pf: PartialFunction[Throwable, U]): Future[U]`	`recover[U >: T](f: PartialFunction[Throwable, U]): Try[U]`
`recoverWith`	`recoverWith[U >: T](pf: PartialFunction[Throwable, Future[U]]): Future[U]`	`recoverWith[U >: T](f: PartialFunction[Throwable, Try[U]]): Try[U]`
`transform`	`transform[S](s: (T) ⇒ S, f: (Throwable) ⇒ Throwable): Future[S]`	`transform[U](s: (T) ⇒ Try[U], f: (Throwable) ⇒ Try[U]): Try[U]`
`filter`	`filter(p: (T) ⇒ Boolean): Future[T]`	`filter(p: (T) ⇒ Boolean): Try[T]`
`withFilter`	`withFilter(p: (T) ⇒ Boolean): Future[T]`	`withFilter(p: (T) ⇒ Boolean): WithFilter`

withFilterだけちょっと違うと言えば違うが、まあ同じように使える。

Futureにだけあるメソッド

isCompleted: Boolean

ready(atMost: Duration)(implicit permit: CanAwait): Future.this.type

result(atMost: Duration)(implicit permit: CanAwait): T

value: Option[Try[T]]

onComplete[U](f: (Try[T]) ⇒ U)(implicit executor: ExecutionContext): Unit

onFailure[U](pf: PartialFunction[Throwable, U])(implicit executor: ExecutionContext): Unit

onSuccess[U](pf: PartialFunction[T, U])(implicit executor: ExecutionContext): Unit

andThen[U](pf: PartialFunction[Try[T], U])(implicit executor: ExecutionContext): Future[T]

collect[S](pf: PartialFunction[T, S])(implicit executor: ExecutionContext): Future[S]

fallbackTo[U >: T](that: Future[U]): Future[U]

mapTo[S](implicit tag: ClassTag[S]): Future[S]

zip[U](that: Future[U]): Future[(T, U)]

collectが意外。Tryにもあっても良さそうなのに。（withFilterとmapで作れるけど）

andThenはfinallyみたいに使ったりする。

https://github.com/scalikejdbc/scalikejdbc/blob/2860c6a09bad974cfb9a5f817b87c2fb1f4341e8/scalikejdbc-core/src/main/scala/scalikejdbc/LoanPattern.scala#L31

mapToはよくわからん。reflection系?

Tryにだけあるメソッド

get: T

isFailure: Boolean

isSuccess: Boolean

getOrElse[U >: T](default: ⇒ U): U

orElse[U >: T](default: ⇒ Try[U]): Try[U]

toOption: Option[T]

Tryにはfinallyみたいなのは無くて、こうするしかないっぽい。

def doSomething(): Try[A] = {
  val resource = open()

  val t = Try { something(resource) }

  resource.close()

  t
}