Scala example source code file (ReplConfig.scala)

This example Scala source code file (ReplConfig.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

any, assertionerror, boolean, compiler, console, controlthrowable, nsc, replconfig, string, t, tapmaker, u, utilities

The ReplConfig.scala Scala example source code

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

package scala.tools.nsc
package interpreter

import scala.util.control.ControlThrowable
import util.Exceptional.unwrap
import util.stackTraceString

trait ReplConfig {
  lazy val replProps = new ReplProps

  class TapMaker[T](x: T) {
    def tapDebug(msg: => String): T = tap(x => repldbg(parens(x)))
    def tap[U](f: T => U): T = {
      f(x)
      x
    }
  }

  private def parens(x: Any) = "(" + x + ")"
  private def echo(msg: => String) =
    try Console println msg
    catch { case x: AssertionError => Console.println("Assertion error printing debugging output: " + x) }

  private[nsc] def repldbg(msg: => String)    = if (isReplDebug) echo(msg)
  private[nsc] def repltrace(msg: => String)  = if (isReplTrace) echo(msg)
  private[nsc] def replinfo(msg: => String)   = if (isReplInfo)  echo(msg)

  private[nsc] def logAndDiscard[T](label: String, alt: => T): PartialFunction[Throwable, T] = {
    case t: ControlThrowable => throw t
    case t: Throwable        =>
      repldbg(label + ": " + unwrap(t))
      repltrace(stackTraceString(unwrap(t)))
      alt
  }
  private[nsc] def substituteAndLog[T](label: String, alt: => T)(body: => T): T = {
    try body
    catch logAndDiscard(label, alt)
  }

  def isReplTrace: Boolean = replProps.trace
  def isReplDebug: Boolean = replProps.debug || isReplTrace
  def isReplInfo: Boolean  = replProps.info || isReplDebug
  def isReplPower: Boolean = replProps.power

  private def csv(p: String, v: String) = p split "," contains v
  def isPaged: Boolean     = replProps.format.isSet && csv(replProps.format.get, "paged")
  def isAcross: Boolean    = replProps.format.isSet && csv(replProps.format.get, "across")
}