From 3f8de98f0b0ec0e10864b37016c2318439ce7898 Mon Sep 17 00:00:00 2001
From: David MacIver <david.maciver@gmail.com>
Date: Mon, 1 Jun 2009 10:22:48 +0000
Subject: Modify TreeSet to use Ordering instead of Order...

Modify TreeSet to use Ordering instead of Ordered to bring it inline
with TreeMap and improve performance.
---
 src/library/scala/Ordering.scala                     |  4 ++++
 src/library/scala/collection/immutable/TreeSet.scala | 16 ++++++++--------
 2 files changed, 12 insertions(+), 8 deletions(-)

(limited to 'src/library')

diff --git a/src/library/scala/Ordering.scala b/src/library/scala/Ordering.scala
index 1a30e24124..e9af2b8a94 100644
--- a/src/library/scala/Ordering.scala
+++ b/src/library/scala/Ordering.scala
@@ -94,6 +94,10 @@ object Ordering
 {
   def apply[T](implicit ord : Ordering[T]) = ord
 
+  def ordered[A <: Ordered[A]] : Ordering[A] = new Ordering[A]{
+    def compare(x : A, y : A) = x.compare(y);
+  }
+
   trait UnitOrdering extends Ordering[Unit] {
     def compare(x : Unit, y : Unit) = 0;
   }
diff --git a/src/library/scala/collection/immutable/TreeSet.scala b/src/library/scala/collection/immutable/TreeSet.scala
index 151760b2c0..87d0042fdb 100644
--- a/src/library/scala/collection/immutable/TreeSet.scala
+++ b/src/library/scala/collection/immutable/TreeSet.scala
@@ -17,16 +17,16 @@ import generic._
 object TreeSet {
 
   type Coll = TreeSet[_]
-  implicit def implicitBuilder[A <% Ordered[A]]: Builder[A, TreeSet[A]] = newBuilder[A]
-  def newBuilder[A <% Ordered[A]]: Builder[A, TreeSet[A]] = new AddingBuilder(empty[A])
+  implicit def implicitBuilder[A](implicit ordering : Ordering[A]) : Builder[A, TreeSet[A]] = newBuilder[A](ordering)
+  def newBuilder[A](implicit ordering : Ordering[A]) : Builder[A, TreeSet[A]] = new AddingBuilder(empty[A](ordering))
 
   /** The empty set of this type
    */
-  def empty[A <% Ordered[A]] = new TreeSet[A]
+  def empty[A](implicit ordering : Ordering[A]) = new TreeSet[A]
 
   /** The canonical factory for this type
    */
-  def apply[A <% Ordered[A]](elems: A*) : TreeSet[A] = empty[A] ++ elems
+  def apply[A](elems: A*)(implicit ordering : Ordering[A]) : TreeSet[A] = empty[A] ++ elems
 }
 
 /** This class implements immutable sets using a tree.
@@ -36,12 +36,12 @@ object TreeSet {
  */
 
 @serializable
-class TreeSet[A <% Ordered[A]](override val size: Int, t: RedBlack[A]#Tree[Unit])
+class TreeSet[A](override val size: Int, t: RedBlack[A]#Tree[Unit])(implicit val ordering : Ordering[A])
   extends RedBlack[A] with SortedSet[A] with SortedSetTemplate[A, TreeSet[A]] {
 
-  def isSmaller(x: A, y: A) = x < y
+  def isSmaller(x: A, y: A) = compare(x,y) < 0
 
-  def this() = this(0, null)
+  def this()(implicit ordering : Ordering[A]) = this(0, null)(ordering)
 
   protected val tree: RedBlack[A]#Tree[Unit] = if (size == 0) Empty else t
 
@@ -94,5 +94,5 @@ class TreeSet[A <% Ordered[A]](override val size: Int, t: RedBlack[A]#Tree[Unit]
   }
   override def firstKey = tree.first
   override def lastKey = tree.last
-  override def compare(a0: A, a1: A) = a0.compare(a1)
+  override def compare(a0: A, a1: A) = ordering.compare(a0, a1);
 }
-- 
cgit v1.2.3