Scala example source code file (TreeFactory.scala)

This example Scala source code file (TreeFactory.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Scala tags/keywords

doctemplateimpl, doctemplateimpl, entity, entity, global, invalid, option, position, select, sourcefile, tree, tree, treefactory, treefactory

The Scala TreeFactory.scala source code

package scala.tools.nsc
package doc
package model

import scala.collection._
import util.{RangePosition, SourceFile}

/** The goal of this trait is , using makeTree,
  * to browse a tree to 
  * 1- have the String of the complete tree (tree.expression)
  * 2- fill references to create hyperLinks later in html.pageTemplate
  * 
  * It is applied in ModelFactory => makeTree
  * 
  */
 
trait TreeFactory { thisTreeFactory: ModelFactory with TreeFactory =>

  val global: Global
  import global._
  
  def makeTree(rhs: Tree): Option[TreeEntity] = {

    var expr = new StringBuilder
    var refs = new immutable.TreeMap[Int, (Entity, Int)] // start, (Entity to be linked to , end)

    val pos: Position = rhs.pos

    if (pos.isInstanceOf[RangePosition]) {

      val source: SourceFile = pos.source
      val firstIndex = pos.startOrPoint
      val lastIndex = pos.endOrPoint

      assert(firstIndex < lastIndex, "Invalid position indices for tree " + rhs + " (" + firstIndex + ", " + lastIndex + ")")
      expr.appendAll(source.content, firstIndex, lastIndex - firstIndex)

      val traverser = new Traverser {

        /** Finds the Entity on which we will later create a link on,
          * stores it in tree.refs with its position
          */
        def makeLink(rhs: Tree){
          var start = pos.startOrPoint - firstIndex
          val end = pos.endOrPoint - firstIndex
          if(start != end) {
            var asym = rhs.symbol
            if (asym.isClass) makeTemplate(asym) match{
              case docTmpl: DocTemplateImpl =>
                refs += ((start, (docTmpl,end)))
              case _ =>
            }
            else if (asym.isTerm && asym.owner.isClass){
              if (asym.isSetter) asym = asym.getter(asym.owner)
              makeTemplate(asym.owner) match {
                case docTmpl: DocTemplateImpl =>
                  val mbrs: List[MemberImpl] = makeMember(asym,docTmpl)
                  mbrs foreach {mbr =>
                    refs += ((start, (mbr,end)))
                  }
                case _ =>
              }
            }
          }
        }
        /**
          * Goes through the tree and makes links when a Select occurs,
          * The case of New(_) is ignored because the object we want to create a link on
          * will be reached with recursivity and we don't want a link on the "new" string
          * If a link is not created, its case is probably not defined in here
          */
        override def traverse(tree: Tree) = tree match {
          case Select(qualifier, name) =>
            qualifier match {
              case New(_) =>
              case _ => makeLink(tree)
            }
            traverse(qualifier)
          case Ident(_) => makeLink(tree)
          case _ =>
            super.traverse(tree)
        }

      }

      traverser.traverse(rhs)

      Some(new TreeEntity {
        val expression = expr.toString
        val refEntity = refs
      })

    }

     // If there is no position for the tree it means it has been obtained through unpickling and cannot be
     // printed as a tree.
    else None

  }
     
}