SI-9656 Range.toString distinguishes Numeric step

For Range and NumericRange, toString will indicate the step
if it is not 1.

Additionally, indicate empty ranges and ranges which are not
"exact".

For a "mapped" range, used by `Range.Double`, toString
includes the underlying range and the simple type of the step
(to distinguish Double from BigDecimal).

1 files changed, 11 insertions, 3 deletions

diff --git a/src/library/scala/collection/immutable/NumericRange.scala b/src/library/scala/collection/immutable/NumericRange.scala
index c8d7519254..fdf50960a3 100644
--- a/src/library/scala/collection/immutable/NumericRange.scala
+++ b/src/library/scala/collection/immutable/NumericRange.scala
@@ -161,6 +161,12 @@ extends AbstractSeq[T] with IndexedSeq[T] with Serializable {
       override def isEmpty = underlyingRange.isEmpty
       override def apply(idx: Int): A = fm(underlyingRange(idx))
       override def containsTyped(el: A) = underlyingRange exists (x => fm(x) == el)
+
+      override def toString = {
+        def simpleOf(x: Any): String = x.getClass.getName.split("\\.").last
+        val stepped = simpleOf(underlyingRange.step)
+        s"${super.toString} (using $underlyingRange of $stepped)"
+      }
     }
   }
 
@@ -250,9 +256,11 @@ extends AbstractSeq[T] with IndexedSeq[T] with Serializable {
       super.equals(other)
   }
 
-  override def toString() = {
-    val endStr = if (length > Range.MAX_PRINT) ", ... )" else ")"
-    take(Range.MAX_PRINT).mkString("NumericRange(", ", ", endStr)
+  override def toString = {
+    val empty = if (isEmpty) "empty " else ""
+    val preposition = if (isInclusive) "to" else "until"
+    val stepped = if (step == 1) "" else s" by $step"
+    s"${empty}NumericRange $start $preposition $end$stepped"
   }
 }