Small updates to collection library:

  - added shorter mkString with single separator parameter
  - ListMap's "elements" Iterator keeps element order.

2 files changed, 16 insertions, 7 deletions

diff --git a/src/library/scala/Iterable.scala b/src/library/scala/Iterable.scala
index 42a5f2eb82..6ef8e2ec06 100644
--- a/src/library/scala/Iterable.scala
+++ b/src/library/scala/Iterable.scala
@@ -359,6 +359,14 @@ trait Iterable[+A] {
     addString(buf, start, sep, end).toString
   }
 
+  /** Returns a string representation of this iterable object. The string
+   *  representations of elements (w.r.t. the method <code>toString()</code>)
+   *  are separated by the string <code>sep</code>.
+   *
+   *  @param sep separator string.
+   *  @return a string representation of this iterable object. */
+  def mkString(sep: String): String = this.mkString("", sep, "")
+
   /** Write all elements of this string into given string builder */
   def addString(buf: StringBuilder, start: String, sep: String, end: String): StringBuilder = {
     buf.append(start)
diff --git a/src/library/scala/collection/immutable/ListMap.scala b/src/library/scala/collection/immutable/ListMap.scala
index 782d471aa4..1705378846 100644
--- a/src/library/scala/collection/immutable/ListMap.scala
+++ b/src/library/scala/collection/immutable/ListMap.scala
@@ -79,13 +79,14 @@ class ListMap[A, +B] extends Map[A, B] {
 
   /** Returns an iterator over key-value pairs.
    */
-  def elements: Iterator[Pair[A,B]] = new Iterator[Pair[A,B]] {
-    var self: ListMap[A,B] = ListMap.this
-    def hasNext = !self.isEmpty
-    def next: Pair[A,B] =
-      if (!hasNext) throw new NoSuchElementException("next on empty iterator")
-      else { val res = Pair(self.key, self.value); self = self.next; res }
-  }
+  def elements: Iterator[Pair[A,B]] =
+    new Iterator[Pair[A,B]] {
+      var self: ListMap[A,B] = ListMap.this
+      def hasNext = !self.isEmpty
+      def next: Pair[A,B] =
+        if (!hasNext) throw new NoSuchElementException("next on empty iterator")
+        else { val res = Pair(self.key, self.value); self = self.next; res }
+    }.toList.reverse.elements
 
   protected def key: A = throw new NoSuchElementException("empty map")
   protected def value: B = throw new NoSuchElementException("empty map")