Scala example source code file (VirtualDirectory.scala)

This example Scala source code file (VirtualDirectory.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

abstractfile, boolean, collection, long, none, option, some, string, virtualdirectory, virtualfile

The VirtualDirectory.scala Scala example source code

/* NSC -- new Scala compiler
 * Copyright 2005-2013 LAMP/EPFL
 */

package scala
package reflect
package io

import scala.collection.mutable

/**
 * An in-memory directory.
 *
 * @author Lex Spoon
 *
 * ''Note:  This library is considered experimental and should not be used unless you know what you are doing.''
 */
class VirtualDirectory(val name: String, maybeContainer: Option[VirtualDirectory])
extends AbstractFile {
  def path: String =
    maybeContainer match {
      case None => name
      case Some(parent) => parent.path+'/'+ name
    }

  def absolute = this

  def container = maybeContainer.get
  def isDirectory = true
  override def isVirtual = true
  val lastModified: Long = System.currentTimeMillis

  override def file = null
  override def input = sys.error("directories cannot be read")
  override def output = sys.error("directories cannot be written")

  /** Does this abstract file denote an existing file? */
  def create() { unsupported() }

  /** Delete the underlying file or directory (recursively). */
  def delete() { unsupported() }

  /** Returns an abstract file with the given name. It does not
   *  check that it exists.
   */
  def lookupNameUnchecked(name: String, directory: Boolean): AbstractFile = unsupported()

  private val files = mutable.Map.empty[String, AbstractFile]

  // the toList is so that the directory may continue to be
  // modified while its elements are iterated
  def iterator = files.values.toList.iterator

  override def lookupName(name: String, directory: Boolean): AbstractFile =
    (files get name filter (_.isDirectory == directory)).orNull

  override def fileNamed(name: String): AbstractFile =
    Option(lookupName(name, directory = false)) getOrElse {
      val newFile = new VirtualFile(name, path+'/'+name)
      files(name) = newFile
      newFile
    }

  override def subdirectoryNamed(name: String): AbstractFile =
    Option(lookupName(name, directory = true)) getOrElse {
      val dir = new VirtualDirectory(name, Some(this))
      files(name) = dir
      dir
    }

  def clear() {
    files.clear()
  }
}