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/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2003-2007, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
// $Id$
package scala
import scala.collection.jcl
private[scala] object internedSymbols extends jcl.HashMap[String, ref.WeakReference[Symbol]]
/** <p>
* Instances of <code>Symbol</code> can be created easily with
* Scala's built-in quote mechanism.
* </p>
* <p>
* For instance, the <a href="http://scala-lang.org/" target="_top">Scala</a>
* term <code>'mysym</code> will invoke the constructor of the
* <code>Symbol</code> class in the following way:
* <code>new Symbol("mysym")</code>.
* </p>
*
* @author Martin Odersky
* @version 1.7, 08/12/2003
*/
final case class Symbol(name: String) {
/** Converts this symbol to a string.
*/
override def toString(): String = {
"'" + name
}
/** <p>
* Makes this symbol into a unique reference.
* </p>
* <p>
* If two interened symbols are equal (i.e. they have the same name)
* then they must be identical (wrt reference equality).
* </p>
*
* @return the unique reference to this symbol.
*/
def intern: Symbol = synchronized {
internedSymbols.get(name).map(.get).getOrElse(None) match {
case Some(sym) => sym
case _ =>
internedSymbols(name) = new ref.WeakReference(this); this
} }
}
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