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/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2003-2011, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
package scala.util.control
/** A class that can be instantiated for the break control abstraction.
* Example usage:
*
* <pre>
* val mybreaks = new Breaks
* import</b> mybreaks.{break, breakable}
*
* breakable {
* <b>for</b> (...) {
* <b>if</b> (...) break
* }
* }</pre>
*
* Calls to break from one instantiation of `Breaks` will never
* target breakable objects of some other instantion.
*/
class Breaks {
private val breakException = new BreakControl
/** A block from which one can exit with a `break`'. */
def breakable(op: => Unit) {
try {
op
} catch {
case ex: BreakControl =>
if (ex ne breakException) throw ex
}
}
trait TryBlock {
def catchBreak(onBreak: => Unit): Unit
}
def tryBreakable(op: => Unit) = new TryBlock {
def catchBreak(onBreak: => Unit) = try {
op
} catch {
case ex: BreakControl =>
if (ex ne breakException) throw ex
onBreak
}
}
/* Break from dynamically closest enclosing breakable block.
*
* @note This might be different than the statically closest enclosing block!
*/
def break() { throw breakException }
}
/** An object that can be used for the break control abstraction.
* Example usage:<pre>
*
* <b>import</b> Breaks.{break, breakable}
*
* breakable {
* <b>for</b> (...) {
* <b>if</b> (...) break
* }
* }</pre>
*
*/
object Breaks extends Breaks
private class BreakControl extends ControlThrowable
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