Scala example source code file (DocParser.scala)

This example Scala source code file (DocParser.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

deftree, docdef, docparser, global, list, name, parsed, reflection, settings, string, tree, utilities

The DocParser.scala Scala example source code

/* NSC -- new Scala compiler
 * Copyright 2005-2013 LAMP/EPFL
 * @author  Paul Phillips
 */

package scala.tools
package nsc
package doc

import reporters._
import scala.reflect.internal.util._
import DocParser.Parsed

/** A very minimal global customized for extracting `DocDefs`.  It stops
 *  right after parsing so it can read `DocDefs` from source code which would
 *  otherwise cause the compiler to go haywire.
 */
class DocParser(settings: nsc.Settings, reporter: Reporter) extends Global(settings, reporter) {
  def this(settings: Settings) = this(settings, new ConsoleReporter(settings))
  def this() = this(new Settings(Console println _))

  // the usual global initialization
  locally { new Run() }

  override protected def computeInternalPhases() {
    phasesSet += syntaxAnalyzer
  }

  /** Returns a list of `DocParser.Parseds`, which hold the DocDefs found
   *  in the given code along with the surrounding trees.
   */
  def docDefs(code: String) = {
    def loop(enclosing: List[Tree], tree: Tree): List[Parsed] = tree match {
      case x: PackageDef => x.stats flatMap (t => loop(enclosing :+ x, t))
      case x: DocDef     => new Parsed(enclosing, x) :: loop(enclosing :+ x.definition, x.definition)
      case x             => x.children flatMap (t => loop(enclosing, t))
    }
    loop(Nil, docUnit(code))
  }

  /** A compilation unit containing parsed source.
   */
  def docUnit(code: String) = {
    val unit    = new CompilationUnit(new BatchSourceFile("<console>", code))
    val scanner = newUnitParser(unit)

    scanner.compilationUnit()
  }
}

/** Since the DocParser's whole reason for existing involves trashing a
 *  global, it is designed to bottle up general `Global#Tree` types rather
 *  than path dependent ones.  The recipient will have to deal.
 */
object DocParser {
  type Tree    = Global#Tree
  type DefTree = Global#DefTree
  type DocDef  = Global#DocDef
  type Name    = Global#Name

  class Parsed(val enclosing: List[Tree], val docDef: DocDef) {
    def nameChain: List[Name] = (enclosing :+ docDef.definition) collect { case x: DefTree => x.name }
    def raw: String           = docDef.comment.raw

    override def toString = (
      nameChain.init.map(x => if (x.isTypeName) x + "#" else x + ".").mkString + nameChain.last
    )
  }
}