无法在Scala中编译和运行多个文件

Question

我是scala新手

我在同一个目录下有两个scala示例文件

一个是：

package chap10

import Element.elem

abstract class Element {

  def contents: Array[String]

  def height: Int = contents.length

  def width: Int =
    if (height == 0) 0 else contents(0).length

  def above(that: Element): Element =
    elem(this.contents ++ that.contents)

  def beside(that: Element): Element =
    elem(
        for (
            (line1, line2) <- this.contents zip that.contents
        ) yield line1 + line2
    )

  private def widen(w: Int): Element =
    if (w <= width) this
    else {
      val left = elem(' ', (w - width) / 2, height)
      val right = elem(' ', w - width - left.width, height)
      left beside this beside right
    }

  private def heighten(h: Int): Element =
    if (h <= height) this
    else {
      val top = elem(' ', width, (h - height) / 2)
      val bottom = elem(' ', width, h - height - top.height)
      top above this above bottom
    }

  override def toString = contents mkString "\n"
}

object Element {

  private class ArrayElement(
    val contents: Array[String]
  ) extends Element

  private class LineElement(s: String) extends Element {
    val contents = Array(s)
    override def width = s.length
    override def height = 1
  }

  private class UniformElement(
    ch: Char,
    override val width: Int,
    override val height: Int
  ) extends Element {
    private val line = ch.toString * width
    def contents = Array.fill(height)(line)
  }

  def elem(contents: Array[String]): Element =
    new ArrayElement(contents)

  def elem(chr: Char, width: Int, height: Int): Element =
    new UniformElement(chr, width, height)

  def elem(line: String): Element =
    new LineElement(line)
}

另一个是

package chap10

import Element.elem

object Spiral {

  val space = elem(" ")
  val corner = elem("+")

  def spiral(nEdges: Int, direction: Int): Element = {
    if (nEdges == 1)
      elem("+")
    else {
      val sp = spiral(nEdges - 1, (direction + 3) % 4)
      def verticalBar = elem('|', 1, sp.height)
      def horizontalBar = elem('-', sp.width, 1)
      if (direction == 0)
        (corner beside horizontalBar) above (sp beside space)
      else if (direction == 1)
        (sp above space) beside (corner above verticalBar)
      else if (direction == 2)
        (space beside sp) above (horizontalBar beside corner)
      else
        (verticalBar above corner) beside (space above sp)
    }
  }

  def main(args: Array[String]) = {
    val nSides = args(0).toInt
    println(spiral(nSides, 0))
  }
}

如果你想参考源代码，链接在这里：https://github.com/vishallama/programming-in-scala-3rd-ed/tree/master/src/chap10

我尝试通过键入以下命令将其转换为字节码：

scalac *.scala

它将在当前目录下创建一个chap10文件夹

然后我试着用

scala chap10.main

它返回

No such file or class on classpath: chap10.main

或者

scala -classpath chap10/Spiral.main

或者

scala -classpath chap10.Spiral.main

所有这些对我来说都没有用。

我知道这可能是一个愚蠢的问题，但我没有太多的java或scala经验，而且我还在学习。

现在我只想让它运行

我有没有漏掉什么步骤？

谢谢大家

更新:在我删除Spiral.scala中的"package chap10“行并运行命令: scala Spiral.scala -classpath Element.scala之后，它给了我这个错误。

aaron$ scala Spiral.scala -classpath Element.scala
Spiral.scala:3: error: not found: object Element
import Element.elem
       ^
Spiral.scala:7: error: not found: value elem
  val space = elem(" ")
              ^
Spiral.scala:8: error: not found: value elem
  val corner = elem("+")
               ^
Spiral.scala:10: error: not found: type Element
  def spiral(nEdges: Int, direction: Int): Element = {
                                           ^
Spiral.scala:12: error: not found: value elem
      elem("+")
      ^
Spiral.scala:15: error: not found: value elem
      def verticalBar = elem('|', 1, sp.height)
                        ^
Spiral.scala:16: error: not found: value elem
      def horizontalBar = elem('-', sp.width, 1)
                          ^

Answer 1

正确的是scala chap10.Spiral

$ ls -R
.:
Element.scala  Spiral.scala

$ scalac *.scala 

$ ls -R
.:
chap10  Element.scala  Spiral.scala    
./chap10:
Element$ArrayElement.class  Element$LineElement.class     Spiral$.class
Element.class               Element$UniformElement.class
Element$.class              Spiral.class

$ scala chap10.Spiral
java.lang.ArrayIndexOutOfBoundsException: 0
    at chap10.Spiral$.main(Spiral.scala:29)
    ...

$ scala chap10.Spiral 10
+--
|  

所有scala chap10.main、scala chap10/Spiral.main、scala chap10.Spiral.main、scala Spiral.scala都是错误的。