Scala example source code file (Driver.scala)

This example Scala source code file (Driver.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

array, compiler, compilercommand, consolereporter, driver, fatalerror, global, nsc, reflection, scala, settings, string, throwable, utilities

The Driver.scala Scala example source code

package scala
package tools.nsc

import scala.tools.nsc.reporters.ConsoleReporter
import Properties.{ versionString, copyrightString, residentPromptString }
import scala.reflect.internal.util.FakePos

abstract class Driver {

  val prompt = residentPromptString

  val versionMsg = "Scala compiler " +
    versionString + " -- " +
    copyrightString

  var reporter: ConsoleReporter = _
  protected var command: CompilerCommand = _
  protected var settings: Settings = _

  protected def scalacError(msg: String) {
    reporter.error(FakePos("scalac"), msg + "\n  scalac -help  gives more information")
  }

  protected def processSettingsHook(): Boolean = true

  protected def newCompiler(): Global

  protected def doCompile(compiler: Global) {
    if (command.files.isEmpty) {
      reporter.echo(command.usageMsg)
      reporter.echo(compiler.pluginOptionsHelp)
    } else {
      val run = new compiler.Run()
      run compile command.files
      reporter.printSummary()
    }
  }

  def process(args: Array[String]) {
    val ss       = new Settings(scalacError)
    reporter     = new ConsoleReporter(ss)
    command  = new CompilerCommand(args.toList, ss)
    settings = command.settings

    if (settings.version) {
      reporter.echo(versionMsg)
    } else if (processSettingsHook()) {
      val compiler = newCompiler()
      try {
        if (reporter.hasErrors)
          reporter.flush()
        else if (command.shouldStopWithInfo)
          reporter.echo(command.getInfoMessage(compiler))
        else
          doCompile(compiler)
      } catch {
        case ex: Throwable =>
          compiler.reportThrowable(ex)
          ex match {
            case FatalError(msg)  => // signals that we should fail compilation.
            case _                => throw ex // unexpected error, tell the outside world.
          }
      }
    }
  }

  def main(args: Array[String]) {
    process(args)
    sys.exit(if (reporter.hasErrors) 1 else 0)
  }

}