（按任意键继续）在 Scala 中

Posted 2023-02-22

【中文标题】（按任意键继续）在 Scala 中

【英文标题】：(Press any key to continue) in Scala

【发布时间】：2015-01-23 20:57:45

【问题描述】：

我是一个有问题的 Scala 新手。

我想从文件中读取文本并一次返回三行，然后等待（任何）键盘输入。问题是让程序在继续之前等待输入。 For-loops 等显然忽略了 readLine():s.

谢谢

val text = source.fromFile(file.txt).getLines.toList
var line = 0

while (line <= text.size)
    readLine(text(line) + "\n" + <Press any key to continue>)
    line += 1

【问题讨论】：

请发布您的代码。

【参考方案1】：

你可以这样做：

def getNext3From[T](list : Seq[T]) = 
  val (three, rest) = list splitAt 3 //splits into two lists at the 3 index. Outputs a tuple of type (Seq[T],Seq[T])
  println(three) //calls tostring on the list of three items
  println("Press any key to continue")
  readChar() //waits for any key to be pressed
  rest //returns the remainder of the list


@scala.annotation.tailrec //Makes sure that this is a tail recursive method
//Recursive method that keeps requesting the next 3 items and forwarding the new list on until empty
def recursiveLooper[T](list : Seq[T]) : Seq[T] = 
  list match 
    case Nil => List()
    case rlist => recursiveLooper(getNext3From(rlist)) 
  

样本 -> recursiveLooper(1 to 9)

【讨论】：

哦哇...乍一看我什至不认识一半的命令...但是我会解决的！谢谢！

我会评论它，如果你觉得它适合你，那么不要忘记接受作为答案。