Scala example source code file (Completion.scala)

This example Scala source code file (Completion.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

candidates, compiler, completion, completionaware, forwarder, int, nil, nocandidates, nsc, nullcompleter, scalacompleter, string

The Completion.scala Scala example source code

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

package scala.tools.nsc
package interpreter

import Completion._

/** An implementation-agnostic completion interface which makes no
 *  reference to the jline classes.
 */
trait Completion {
  def resetVerbosity(): Unit
  def completer(): ScalaCompleter
}
object NoCompletion extends Completion {
  def resetVerbosity() = ()
  def completer() = NullCompleter
}

object Completion {
  case class Candidates(cursor: Int, candidates: List[String]) { }
  val NoCandidates = Candidates(-1, Nil)

  object NullCompleter extends ScalaCompleter {
    def complete(buffer: String, cursor: Int): Candidates = NoCandidates
  }
  trait ScalaCompleter {
    def complete(buffer: String, cursor: Int): Candidates
  }

  def looksLikeInvocation(code: String) = (
        (code != null)
    &&  (code startsWith ".")
    && !(code == ".")
    && !(code startsWith "./")
    && !(code startsWith "..")
  )
  object Forwarder {
    def apply(forwardTo: () => Option[CompletionAware]): CompletionAware = new CompletionAware {
      def completions(verbosity: Int) = forwardTo() map (_ completions verbosity) getOrElse Nil
      override def follow(s: String) = forwardTo() flatMap (_ follow s)
    }
  }
}