Scala的编码方式

Question

我正在从C/c++迁移到Scala，以下是我的代码-

something match {
case one: {
if (some_list.nonEmpty) {
if (some_list size == 1 && some_list contains == something)
fill a form(use something in a certain way)
else if (some_list size == 1 && some_list contains == soemthing_else)
fill a form(use something_else in a certain way)
else {
if (some_var.nonEmpty) {
fill a form(use some_var)
} else {
fill a form(without using some_var)
}
}
} else {
if (another_var has certain value || another_var has certain value 2) {
fill a form(using another_var)
} else {
fill a form(without using another_var)
}
} //if (some_list.nonEmpty) ends
} // case ends

case two: one liner code
case _: one liner code
} //match ends

看以使用scala的特性和优势，以良好的scala方式编写它的指导。谢谢你

Answer 1

我做了一些假设来使这个工作:

trait cases
case object one extends cases
case object two extends cases
case object three extends cases
case object four extends cases
val someList: List[cases] = List(one, two)
val something: cases = one
val somethingElse: cases = two
val someVar: Option[String] = Option("someVar")
val someOtherVar: Option[String] = Option("someOtherVar")
val anotherVar: Option[String] = Option("anotherVar")

以下是使用上述代码的简化版本:

something match {
case `one` => 
someList match {
case head :: Nil if(head == something) => println("one")
case head :: Nil if(head == somethingElse) => println("two")
case head :: tail if(someVar.nonEmpty) => println("someVar")
case head :: tail if(someOtherVar.nonEmpty) => println("someOtherVar")
case head :: tail => println("not using someOtherVar")
case Nil if(anotherVar.nonEmpty) => println("anotherVar")
case Nil => println("not using anotherVar")
}
case `two` => println("two")
case _ => println("rest")
}