Fix for #1993.

1 files changed, 11 insertions, 15 deletions

diff --git a/src/library/scala/util/parsing/combinator/lexical/StdLexical.scala b/src/library/scala/util/parsing/combinator/lexical/StdLexical.scala
index 2489c623e9..9cacf37ca2 100644
--- a/src/library/scala/util/parsing/combinator/lexical/StdLexical.scala
+++ b/src/library/scala/util/parsing/combinator/lexical/StdLexical.scala
@@ -71,23 +71,19 @@ class StdLexical extends Lexical with StdTokens {
   protected def processIdent(name: String) =
     if (reserved contains name) Keyword(name) else Identifier(name)
 
-  private var _delim: Parser[Token] = null
-  protected def delim: Parser[Token] = {
-    if (_delim eq null) { // construct parser for delimiters by |'ing together the parsers for the individual delimiters,
-    // starting with the longest one (hence the sort + reverse) -- otherwise a delimiter D will never be matched if
-    // there is another delimiter that is a prefix of D
-      def parseDelim(s: String): Parser[Token] = accept(s.toList) ^^ { x => Keyword(s) }
-
-      val d = new Array[String](delimiters.size)
-      delimiters.copyToArray(d,0)
-      scala.util.Sorting.quickSort(d)
-      _delim = d.toList.reverse.map(parseDelim).reduceRight[Parser[Token]](_ | _) // no offence :-)
-    }
-
-    _delim
+  private lazy val _delim: Parser[Token] = {
+    // construct parser for delimiters by |'ing together the parsers for the individual delimiters,
+    // starting with the longest one -- otherwise a delimiter D will never be matched if there is
+    // another delimiter that is a prefix of D
+    def parseDelim(s: String): Parser[Token] = accept(s.toList) ^^ { x => Keyword(s) }
+
+    val d = new Array[String](delimiters.size)
+    delimiters.copyToArray(d, 0)
+    scala.util.Sorting.quickSort(d)
+    (d.toList map parseDelim).foldRight(failure("no matching delimiter"): Parser[Token])((x, y) => y | x)
   }
+  protected def delim: Parser[Token] = _delim
 
   private def lift[T](f: String => T)(xs: List[Char]): T = f(xs.mkString("", "", ""))
-
   private def lift2[T](f: String => T)(p: ~[Char, List[Char]]): T = lift(f)(p._1 :: p._2)
 }