scala.annotation.elidable.scala Maven / Gradle / Ivy

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/*                     __                                               *\
**     ________ ___   / /  ___     Scala API                            **
**    / __/ __// _ | / /  / _ |    (c) 2002-2010, LAMP/EPFL             **
**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
** /____/\___/_/ |_/____/_/ | |                                         **
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\*                                                                      */

package scala.annotation

import java.util.logging.Level
 
/** An annotation for methods for which invocations might
 *  be removed in the generated code.
 * 
 *  Behavior is influenced by passing -Xelide-below 
 *  to scalac.  Methods marked elidable will be omitted from
 *  generated code if the priority given the annotation is lower
 *  than to the command line argument.  Examples:
 *  {{{
 *  import annotation.elidable._
 * 
 *    @elidable(WARNING) def foo = log("foo")
 *    @elidable(FINE) def bar = log("bar")
 *
 *  scalac -Xelide-below=1000
 *  }}}
 *  @since 2.8
 */
final class elidable(final val level: Int) extends StaticAnnotation {}

/** This useless appearing code was necessary to allow people to use
 *  named constants for the elidable annotation.  This is what it takes
 *  to convince the compiler to fold the constants: otherwise when it's
 *  time to check an elision level it's staring at a tree like
 *    (Select(Level, Select(FINEST, Apply(intValue, Nil))))
 *  instead of the number 300.
 *
 *  @since 2.8
 */
object elidable {
  final val ALL = Int.MinValue  // Level.ALL.intValue()
  final val FINEST = 300        // Level.FINEST.intValue()
  final val FINER = 400         // Level.FINER.intValue()
  final val FINE = 500          // Level.FINE.intValue()
  final val CONFIG = 700        // Level.CONFIG.intValue()
  final val INFO = 800          // Level.INFO.intValue()
  final val WARNING = 900       // Level.WARNING.intValue()
  final val SEVERE = 1000       // Level.SEVERE.intValue()
  final val OFF = Int.MaxValue  // Level.OFF.intValue()
  
  // and since we had to do that anyway, we can add a few of our own
  final val ASSERTION = 2000    // we should make this more granular
  
  // for command line parsing so we can use names or ints
  val byName: Map[String, Int] = Map(
    "ALL" -> ALL,
    "FINEST" -> FINEST,
    "FINER" -> FINER,
    "FINE" -> FINE,
    "CONFIG" -> CONFIG,
    "INFO" -> INFO,
    "WARNING" -> WARNING,
    "SEVERE" -> SEVERE,
    "OFF" -> OFF,
    "ASSERTION" -> ASSERTION
  )
}