minor adaption for scala-2.9.0.final;

--- a/src/Pure/General/linear_set.scala	Thu May 12 16:23:13 2011 +0200
+++ b/src/Pure/General/linear_set.scala	Thu May 12 16:28:46 2011 +0200
@@ -14,7 +14,7 @@
 
 object Linear_Set extends ImmutableSetFactory[Linear_Set]
 {
-  private case class Rep[A](
+  protected case class Rep[A](
     val start: Option[A], val end: Option[A], val nexts: Map[A, A], prevs: Map[A, A])
 
   private def empty_rep[A] = Rep[A](None, None, Map(), Map())

--- a/src/Pure/General/scan.scala	Thu May 12 16:23:13 2011 +0200
+++ b/src/Pure/General/scan.scala	Thu May 12 16:28:46 2011 +0200
@@ -22,7 +22,7 @@
 
   object Lexicon
   {
-    private case class Tree(val branches: Map[Char, (String, Tree)])
+    protected case class Tree(val branches: Map[Char, (String, Tree)])
     private val empty_tree = Tree(Map())
 
     val empty: Lexicon = new Lexicon