Scala example source code file (InfoTransformers.scala)

This example Scala source code file (InfoTransformers.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

boolean, id, infotransformer, infotransformers, inserting, phase, symbol, symboltable, type

The InfoTransformers.scala Scala example source code

/* NSC -- new Scala compiler
 * Copyright 2005-2013 LAMP/EPFL
 * @author  Martin Odersky
 */

package scala
package reflect
package internal

trait InfoTransformers {
  self: SymbolTable =>

  /* Syncnote: This should not need to be protected, as reflection does not run in multiple phases.
   */
  abstract class InfoTransformer {
    var prev: InfoTransformer = this
    var next: InfoTransformer = this

    val pid: Phase#Id
    val changesBaseClasses: Boolean
    def transform(sym: Symbol, tpe: Type): Type

    def insert(that: InfoTransformer) {
      assert(this.pid != that.pid, this.pid)

      if (that.pid < this.pid) {
        prev insert that
      } else if (next.pid <= that.pid && next.pid != NoPhase.id) {
        next insert that
      } else {
        log("Inserting info transformer %s following %s".format(phaseOf(that.pid), phaseOf(this.pid)))
        that.next = next
        that.prev = this
        next.prev = that
        this.next = that
      }
    }

    /** The InfoTransformer whose (pid == from).
     *  If no such exists, the InfoTransformer with the next
     *  higher pid.
     */
    def nextFrom(from: Phase#Id): InfoTransformer =
      if (from == this.pid) this
      else if (from < this.pid)
        if (prev.pid < from) this
        else prev.nextFrom(from)
      else if (next.pid == NoPhase.id) next
      else next.nextFrom(from)
  }
}