Scala example source code file (Reify.scala)

This example Scala source code file (Reify.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

any, existentialtype, gentypes, genutils, list, literal, reflection, reifier, reify, string, t, tree

The Reify.scala Scala example source code

package scala.reflect.reify
package phases

import scala.runtime.ScalaRunTime.isAnyVal
import scala.reflect.reify.codegen._

trait Reify extends GenSymbols
               with GenTypes
               with GenNames
               with GenTrees
               with GenAnnotationInfos
               with GenPositions
               with GenUtils {

  self: Reifier =>

  import global._

  private object reifyStack {
    def currents: List[Any] = state.reifyStack
    def currents_=(value: List[Any]): Unit = state.reifyStack = value

    @inline final def push[T](reifee: Any)(body: => T): T = {
      currents ::= reifee
      try body
      finally currents = currents.tail
    }
  }
  def boundSymbolsInCallstack = flatCollect(reifyStack.currents) {
    case ExistentialType(quantified, _) => quantified
    case PolyType(typeParams, _) => typeParams
  }
  def current = reifyStack.currents.head
  def currents = reifyStack.currents

  /**
   *  Reifies any supported value.
   *  For internal use only, use `reified` instead.
   */
  def reify(reifee: Any): Tree = reifyStack.push(reifee)(reifee match {
    // before adding some case here, in global scope, please, consider
    // whether it can be localized like reifyAnnotationInfo or reifyScope
    // this will help reification stay as sane as possible
    case sym: Symbol              => reifySymRef(sym)
    case tpe: Type                => reifyType(tpe)
    case name: Name               => reifyName(name)
    case tree: Tree               => reifyTree(tree)
    // disabled because this is a very special case that I plan to remove later
    // why do I dislike annotations? see comments to `reifyAnnotationInfo`
    // case ann: AnnotationInfo      => reifyAnnotationInfo(ann)
    case pos: Position            => reifyPosition(pos)
    case mods: global.Modifiers   => reifyModifiers(mods)
    case xs: List[_]              => reifyList(xs)
    case s: String                => Literal(Constant(s))
    case v if isAnyVal(v)         => Literal(Constant(v))
    case null                     => Literal(Constant(null))
    case _                        =>
      throw new Error("reifee %s of type %s is not supported".format(reifee, reifee.getClass))
  })
}