Scala example source code file (NonFatal.scala)

This example Scala source code file (NonFatal.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

boolean, controlthrowable, interruptedexception, none, nonfatal, option, some, threaddeath, throwable, virtualmachineerror

The NonFatal.scala Scala example source code

/*                     __                                               *\
**     ________ ___   / /  ___     Scala API                            **
**    / __/ __// _ | / /  / _ |    (c) 2003-2013, LAMP/EPFL             **
**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
** /____/\___/_/ |_/____/_/ | |                                         **
**                          |/                                          **
\*                                                                      */

package scala
package util.control

/**
 * Extractor of non-fatal Throwables. Will not match fatal errors like `VirtualMachineError`
 * (for example, `OutOfMemoryError` and `StackOverflowError`, subclasses of `VirtualMachineError`), `ThreadDeath`,
 * `LinkageError`, `InterruptedException`, `ControlThrowable`.
 *
 * Note that [[scala.util.control.ControlThrowable]], an internal Throwable, is not matched by
 * `NonFatal` (and would therefore be thrown).
 *
 * For example, all harmless Throwables can be caught by:
 * {{{
 *   try {
 *     // dangerous stuff
 *   } catch {
 *     case NonFatal(e) => log.error(e, "Something not that bad.")
 *    // or
 *     case e if NonFatal(e) => log.error(e, "Something not that bad.")
 *   }
 * }}}
 */
object NonFatal {
   /**
    * Returns true if the provided `Throwable` is to be considered non-fatal, or false if it is to be considered fatal
    */
   def apply(t: Throwable): Boolean = t match {
     // VirtualMachineError includes OutOfMemoryError and other fatal errors
     case _: VirtualMachineError | _: ThreadDeath | _: InterruptedException | _: LinkageError | _: ControlThrowable => false
     case _ => true
   }
  /**
   * Returns Some(t) if NonFatal(t) == true, otherwise None
   */
  def unapply(t: Throwable): Option[Throwable] = if (apply(t)) Some(t) else None
}