Scala example source code file (Enclosures.scala)

This example Scala source code file (Enclosures.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

classtag, compilationunit, defdef, enclosures, list, macro, noposition, position, reflection, t, template, tree

The Enclosures.scala Scala example source code

package scala.reflect.macros
package contexts

import scala.reflect.{ClassTag, classTag}

trait Enclosures {
  self: Context =>

  import universe._

  private lazy val site       = callsiteTyper.context
  private lazy val enclTrees  = site.enclosingContextChain map (_.tree)
  private lazy val enclPoses  = enclosingMacros map (_.macroApplication.pos) filterNot (_ eq NoPosition)

  private def lenientEnclosure[T <: Tree : ClassTag]: Tree = enclTrees collectFirst { case x: T => x } getOrElse EmptyTree
  private def strictEnclosure[T <: Tree : ClassTag]: T = enclTrees collectFirst { case x: T => x } getOrElse (throw new EnclosureException(classTag[T].runtimeClass, enclTrees))

  // vals are eager to simplify debugging
  // after all we wouldn't save that much time by making them lazy
  val macroApplication: Tree                      = expandee
  def enclosingPackage: PackageDef                = strictEnclosure[PackageDef]
  val enclosingClass: Tree                        = lenientEnclosure[ImplDef]
  def enclosingImpl: ImplDef                      = strictEnclosure[ImplDef]
  def enclosingTemplate: Template                 = strictEnclosure[Template]
  val enclosingImplicits: List[ImplicitCandidate] = site.openImplicits.map(_.toImplicitCandidate)
  val enclosingMacros: List[Context]              = this :: universe.analyzer.openMacros // include self
  val enclosingMethod: Tree                       = lenientEnclosure[DefDef]
  def enclosingDef: DefDef                        = strictEnclosure[DefDef]
  val enclosingPosition: Position                 = if (enclPoses.isEmpty) NoPosition else enclPoses.head.pos
  val enclosingUnit: CompilationUnit              = universe.currentRun.currentUnit
  val enclosingRun: Run                           = universe.currentRun
}