bugfix + comment

2 files changed, 27 insertions, 8 deletions

diff --git a/src/library/scala/util/automata/BaseBerrySethi.scala b/src/library/scala/util/automata/BaseBerrySethi.scala
index 35dab49a8f..c7adf744c7 100644
--- a/src/library/scala/util/automata/BaseBerrySethi.scala
+++ b/src/library/scala/util/automata/BaseBerrySethi.scala
@@ -52,16 +52,17 @@ abstract class BaseBerrySethi {
     case Eps => emptySet;
     //case x:Letter => emptySet + posMap(x);  // singleton set
     case x:Meta => compFirst( x.r )
-    case x:Sequ   =>
+    case x:Sequ =>
       var tmp = emptySet;
       val it = x.rs.elements;                       // union
       while( it.hasNext ) {
-      val z = it.next;
-      tmp = tmp incl compFirst( z );
-      if( !z.isNullable )
-        return tmp
-      };
-    tmp
+	val z = it.next
+	tmp = tmp incl compFirst( z )
+	if( !z.isNullable )
+          return tmp
+      }
+      tmp
+    case Star(t)  => compFirst(t);
     case _ => error("unexpected pattern " + Platform.getClass(r));
   }
 
diff --git a/src/library/scala/util/regexp/WordExp.scala b/src/library/scala/util/regexp/WordExp.scala
index 14bcbb3ec1..fdf795bb61 100644
--- a/src/library/scala/util/regexp/WordExp.scala
+++ b/src/library/scala/util/regexp/WordExp.scala
@@ -12,7 +12,25 @@
 package scala.util.regexp ;
 
 
-/** regular word expressions.
+/** regular word expressions. users have to instantiate type member _regexpT <: RegExp (from Base) and a type member _labelT <: Label
+ *  Here is a little example:
+<pre>
+  import scala.util.regexp._
+  import scala.util.automata._
+  object MyLang extends WordExp {
+    type _regexpT = RegExp
+    type _labelT = MyChar
+
+    case class MyChar(c:Char) extends Label
+  }
+  import MyLang._
+  // (a* | b)*
+  val rex = Star(Alt(Star(Letter(MyChar('a'))),Letter(MyChar('b'))))
+  object MyBerriSethi extends WordBerrySethi {
+    override val lang = MyLang
+  }
+  val nfa = MyBerriSethi.automatonFrom(Sequ(rex),1)
+</pre>
  */
 abstract class WordExp extends Base {