Scala example source code file (DelayedInit.scala)

This example Scala source code file (DelayedInit.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

app, delayedinit, support, unit

The DelayedInit.scala Scala example source code

/*                     __                                               *\
**     ________ ___   / /  ___     Scala API                            **
**    / __/ __// _ | / /  / _ |    (c) 2010-2013, LAMP/EPFL             **
**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
** /____/\___/_/ |_/____/_/ | |                                         **
**                          |/                                          **
\*                                                                      */

package scala

/** Classes and objects (but note, not traits) inheriting the `DelayedInit`
 *  marker trait will have their initialization code rewritten as follows:
 *  `code` becomes `delayedInit(code)`.
 *
 *  Initialization code comprises all statements and all value definitions
 *  that are executed during initialization.
 *
 *  Example:
 *  {{{
 *    trait Helper extends DelayedInit {
 *      def delayedInit(body: => Unit) = {
 *        println("dummy text, printed before initialization of C")
 *        body // evaluates the initialization code of C
 *      }
 *    }
 *
 *    class C extends Helper {
 *      println("this is the initialization code of C")
 *    }
 *
 *    object Test extends App {
 *      val c = new C
 *    }
 *  }}}
 *
 *  Should result in the following being printed:
 *  {{{
 *    dummy text, printed before initialization of C
 *    this is the initialization code of C
 *  }}}
 *
 *  @see "Delayed Initialization" subsection of the Scala Language Specification (section 5.1)
 *
 *  @author  Martin Odersky
 */
@deprecated("DelayedInit semantics can be surprising. Support for `App` will continue.\nSee the release notes for more details: https://github.com/scala/scala/releases/tag/v2.11.0-RC1", "2.11.0")
trait DelayedInit {
  def delayedInit(x: => Unit): Unit
}