/* NSC -- new Scala compiler * Copyright 2005-2009 LAMP/EPFL * @author Martin Odersky */ // $Id: WorklistAlgorithm.scala 18387 2009-07-24 15:28:37Z odersky $ package scala.tools.nsc package backend import scala.tools.nsc.ast._ import scala.collection.mutable.Stack /** * Simple implementation of a worklist algorithm. A processing * function is applied repeatedly to the first element in the * worklist, as long as the stack is not empty. * * The client class should mix-in this class and initialize the * worklist field and define the <code>processElement</code> method. * Then call the <code>run</code> method providing a function that * initializes the worklist. * * @author Martin Odersky * @version 1.0 * @see <a href="icode/Linearizers.html" target="contentFrame">scala.tools.nsc.backend.icode.Linearizers</a> */ trait WorklistAlgorithm { type Elem type WList = Stack[Elem] val worklist: WList /** * Run the iterative algorithm until the worklist * remains empty. The initializer is run once before * the loop starts and should initialize the worklist. * * @param initWorklist ... */ def run(initWorklist: => Unit) = { initWorklist while (!(worklist.length == 0)) processElement(dequeue); } /** * Process the current element from the worklist. */ def processElement(e: Elem): Unit /** * Remove and return the first element to be processed from the worklist. */ def dequeue: Elem }