From cc1f6bca81c9f524952b4b42b45d8e36d8df6387 Mon Sep 17 00:00:00 2001
From: Paul Phillips <paulp@improving.org>
Date: Fri, 3 Dec 2010 06:17:23 +0000
Subject: Parameterizes TraversableFactory.range so it ca...

Parameterizes TraversableFactory.range so it can be used with any
integral type. Closes #3542, no review.
---
 .../scala/collection/generic/TraversableFactory.scala     | 15 +++++++++------
 src/library/scala/collection/immutable/Stream.scala       |  8 ++++++--
 src/library/scala/math/Equiv.scala                        |  7 +++----
 3 files changed, 18 insertions(+), 12 deletions(-)

(limited to 'src/library')

diff --git a/src/library/scala/collection/generic/TraversableFactory.scala b/src/library/scala/collection/generic/TraversableFactory.scala
index c6f5ce4dde..55022349eb 100644
--- a/src/library/scala/collection/generic/TraversableFactory.scala
+++ b/src/library/scala/collection/generic/TraversableFactory.scala
@@ -195,7 +195,7 @@ abstract class TraversableFactory[CC[X] <: Traversable[X] with GenericTraversabl
    *  @param end the end value of the $coll (the first value NOT contained)
    *  @return  a $coll with values `start, start + 1, ..., end - 1`
    */
-  def range(start: Int, end: Int): CC[Int] = range(start, end, 1)
+  def range[T: Integral](start: T, end: T): CC[T] = range(start, end, implicitly[Integral[T]].one)
 
   /** Produces a $coll containing equally spaced values in some integer interval.
    *  @param start the start value of the $coll
@@ -203,12 +203,15 @@ abstract class TraversableFactory[CC[X] <: Traversable[X] with GenericTraversabl
    *  @param step  the difference between successive elements of the $coll (must be positive or negative)
    *  @return      a $coll with values `start, start + step, ...` up to, but excluding `end`
    */
-  def range(start: Int, end: Int, step: Int): CC[Int] = {
-    if (step == 0) throw new IllegalArgumentException("zero step")
-    val b = newBuilder[Int]
-    b.sizeHint(Range.count(start, end, step, false))
+  def range[T: Integral](start: T, end: T, step: T): CC[T] = {
+    val num = implicitly[Integral[T]]
+    import num._
+
+    if (step == zero) throw new IllegalArgumentException("zero step")
+    val b = newBuilder[T]
+    b sizeHint immutable.NumericRange.count(start, end, step, false)
     var i = start
-    while (if (step < 0) end < i else i < end) {
+    while (if (step < zero) end < i else i < end) {
       b += i
       i += step
     }
diff --git a/src/library/scala/collection/immutable/Stream.scala b/src/library/scala/collection/immutable/Stream.scala
index 04fe6225b4..3f16c2c020 100644
--- a/src/library/scala/collection/immutable/Stream.scala
+++ b/src/library/scala/collection/immutable/Stream.scala
@@ -675,9 +675,13 @@ object Stream extends SeqFactory[Stream] {
     loop(0)
   }
 
-  override def range(start: Int, end: Int, step: Int): Stream[Int] =
-    if (if (step < 0) start <= end else end <= start) Empty
+  override def range[T: Integral](start: T, end: T, step: T): Stream[T] = {
+    val num = implicitly[Integral[T]]
+    import num._
+
+    if (if (step < zero) start <= end else end <= start) Empty
     else new Cons(start, range(start + step, end, step))
+  }
 
   private[immutable] def filteredTail[A](stream: Stream[A], p: A => Boolean) = {
     new Stream.Cons(stream.head, stream.tail filter p)
diff --git a/src/library/scala/math/Equiv.scala b/src/library/scala/math/Equiv.scala
index c09b4c577b..b7466b2e4e 100644
--- a/src/library/scala/math/Equiv.scala
+++ b/src/library/scala/math/Equiv.scala
@@ -39,10 +39,6 @@ trait LowPriorityEquiv {
   self: Equiv.type =>
 
   implicit def universalEquiv[T] : Equiv[T] = universal[T]
-
-  implicit def comparatorToEquiv[T](cmp: Comparator[T]): Equiv[T] = new Equiv[T] {
-    def equiv(x: T, y: T) = cmp.compare(x, y) == 0
-  }
 }
 
 object Equiv extends LowPriorityEquiv {
@@ -52,6 +48,9 @@ object Equiv extends LowPriorityEquiv {
   def universal[T] : Equiv[T] = new Equiv[T] {
     def equiv(x: T, y: T) = x == y
   }
+  def fromComparator[T](cmp: Comparator[T]): Equiv[T] = new Equiv[T] {
+    def equiv(x: T, y: T) = cmp.compare(x, y) == 0
+  }
   def fromFunction[T](cmp: (T, T) => Boolean): Equiv[T] = new Equiv[T] {
     def equiv(x: T, y: T) = cmp(x, y)
   }
-- 
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