[Scala] List의 sort는 deprecated, sortWith, sortBy, sorted 활용 예시

scala 2.8에서 List의 sort 메소드는 deprecated되었고, 뒤 버전부터 사라졌다. 

1. defsort (lt: (A, A) ⇒ Boolean) : List[A]

   Sort the list according to the comparison function lt(e1: a, e2: a) => Boolean, which should be true iff e1 precedes e2 in the desired ordering. !!! todo: move sorting to IterableLike

   lt

   the comparison function

   returns

   a list sorted according to the comparison function lt(e1: a, e2: a) => Boolean.

   deprecated: 

   1. use sortWith' instead

2. defsortBy [B] (f: (A) ⇒ B)(implicit ord: Ordering[B]) : List[A]

   Sorts this List according to the Ordering which results from transforming an implicitly given Ordering with a transformation function.

3. defsortWith (lt: (A, A) ⇒ Boolean) : List[A]

   Sorts this list according to a comparison function.

4. defsorted [B >: A] (implicit ord: Ordering[B]) : List[A]

   Sorts this list according to an Ordering.

http://www.scala-lang.org/api/current/#scala.collection.immutable.List에서도 확인할 수 있다. (현재 2.11.8)

scala> thrill.sort((s,t) => s.charAt(0).toLower < t.charAt(0).toLower)

<console>:14: error: value sort is not a member of List[String]

       thrill.sort((s,t) => s.charAt(0).toLower < t.charAt(0).toLower)

              ^

scala> thrill.sortWith((s,t) => s.charAt(0).toLower < t.charAt(0).toLower)

res11: List[String] = List(aa, bb)

scala> thrill.sortWith(_.charAt(0).toLower < _.charAt(0).toLower)

res12: List[String] = List(aa, bb)

scala> thrill.sortBy(_.charAt(0))

res14: List[String] = List(aa, bb)

scala> thrill.sorted

res15: List[String] = List(aa, bb)