Scala 練習問題 #daimonscala

gistfile1.sbt

import scala.annotation.tailrec

class StringSupport(s: String) {
  def reverseOrder: String = s.toList.foldLeft(Nil: List[Char])((result, c) => c :: result).mkString

  def reverseCase: String = s.toList.foldRight(Nil: List[Char])((c, result) => c match {
    case c if c.isUpper => c.toLower :: result
    case c if c.isLower => c.toUpper :: result
    case c => c :: result
  }).mkString
}

object StringSupport {
  implicit def convert(s: String): StringSupport = new StringSupport(s)
}

import StringSupport._
println("AbcDEf123".reverseOrder)
println("AbcDEf123".reverseCase)