Scala example source code file (Spec.scala)

This example Scala source code file (Spec.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Scala source code examples by using tags.

All credit for the original source code belongs to scala-lang.org; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Scala tags/keywords

choices, fromstring, info, list, nil, optionmagic, spec, string, t, unit

The Spec.scala Scala example source code

/* NSC -- new Scala compiler
 * Copyright 2005-2013 LAMP/EPFL
 * @author  Paul Phillips
 */

package scala.tools
package cmd

/** This trait works together with others in scala.tools.cmd to allow
 *  declaratively specifying a command line program, with many attendant
 *  benefits.  See scala.tools.cmd.DemoSpec for an example.
 */
trait Spec {
  def referenceSpec: Reference
  def programInfo: Spec.Info

  protected def help(str: => String): Unit
  protected def heading(str: => String): Unit = help(s"\n  $str")

  type OptionMagic <: Opt.Implicit
  protected implicit def optionMagicAdditions(s: String): OptionMagic
}

object Spec {
  class Info(
    val runner: String,
    val usage: String,
    val mainClass: String
  )
  object Info {
    def apply(runner: String, help: String, mainClass: String): Info = new Info(runner, help, mainClass)
  }

  class Accumulator[T: FromString]() {
    private var _buf: List[T] = Nil

    def convert(s: String)    = implicitly[FromString[T]] apply s
    def apply(s: String): T   = returning(convert(s))(_buf +:= _)

    lazy val get = _buf
  }

  class Choices[T: FromString](val xs: List[T]) {
    def fs: FromString[T] = implicitly[FromString[T]]
    def contains(x: T)    = xs contains x
    override def toString = xs.mkString("{ ", ", ", " }")
  }

  class EnvironmentVar(val name: String) {
    override def toString = "${%s}" format name
  }
}