From da5910c7c622fc248fe525f5c03b1dee6be384b5 Mon Sep 17 00:00:00 2001
From: Paul Phillips <paulp@improving.org>
Date: Fri, 4 Jun 2010 18:34:02 +0000
Subject: Fix for init-order caused NPE in NumericRange.

ran across some tortured logic trying to accomodate the long abandoned
idea of having 5 != 5L, so simplified the contains method. Closes #3518,
no review.
---
 .../scala/collection/immutable/NumericRange.scala  | 45 ++++++++--------------
 test/files/run/bug3518.scala                       | 16 ++++++++
 2 files changed, 33 insertions(+), 28 deletions(-)
 create mode 100644 test/files/run/bug3518.scala

diff --git a/src/library/scala/collection/immutable/NumericRange.scala b/src/library/scala/collection/immutable/NumericRange.scala
index db44e9ffa0..b8bd5bd20e 100644
--- a/src/library/scala/collection/immutable/NumericRange.scala
+++ b/src/library/scala/collection/immutable/NumericRange.scala
@@ -40,8 +40,8 @@ import generic._
 abstract class NumericRange[T]
   (val start: T, val end: T, val step: T, val isInclusive: Boolean)
   (implicit num: Integral[T])
-extends IndexedSeq[T]
-{
+extends IndexedSeq[T] {
+
   /** Note that NumericRange must be invariant so that constructs
    *  such as
    *
@@ -122,18 +122,6 @@ extends IndexedSeq[T]
     else start + (fromInt(idx) * step)
   }
 
-  // a well-typed contains method.
-  def containsTyped(x: T): Boolean = {
-    def divides(d: T, by: T) = equiv(d % by, zero)
-
-    limitTest(x) || (
-      if (step > zero)
-        (start <= x) && (x < end) && divides(x - start, step)
-      else
-        (start >= x) && (x > end) && divides(start - x, step)
-    )
-  }
-
   // Motivated by the desire for Double ranges with BigDecimal precision,
   // we need some way to map a Range and get another Range.  This can't be
   // done in any fully general way because Ranges are not arbitrary
@@ -165,7 +153,7 @@ extends IndexedSeq[T]
         if (isInclusive) NumericRange.inclusive(start, end, step)
         else NumericRange(start, end, step)
 
-      private val underlyingRange: NumericRange[T] = self
+      private lazy val underlyingRange: NumericRange[T] = self
       override def foreach[U](f: A => U) { underlyingRange foreach (x => f(fm(x))) }
       override def isEmpty = underlyingRange.isEmpty
       override def apply(idx: Int): A = fm(underlyingRange(idx))
@@ -173,20 +161,21 @@ extends IndexedSeq[T]
     }
   }
 
-  // The contains situation makes for some interesting code.
-  // I am not aware of any way to avoid a cast somewhere, because
-  // contains must take an Any.
+  // a well-typed contains method.
+  def containsTyped(x: T): Boolean = {
+    def divides(d: T, by: T) = equiv(d % by, zero)
+
+    limitTest(x) || (
+      if (step > zero)
+        (start <= x) && (x < end) && divides(x - start, step)
+      else
+        (start >= x) && (x > end) && divides(start - x, step)
+    )
+  }
+
   override def contains(x: Any): Boolean =
-    try {
-      // if we don't verify that x == typedX, then a range
-      // of e.g. Longs will appear to contain an Int because
-      // the cast will perform the conversion.  (As of this writing
-      // it is anticipated that in scala 2.8, 5L != 5 although
-      // this is not yet implemented.)
-      val typedX = x.asInstanceOf[T]
-      containsTyped(typedX) && (x == typedX)
-    }
-    catch { case _: ClassCastException => super.contains(x) }
+    try containsTyped(x.asInstanceOf[T])
+    catch { case _: ClassCastException => false }
 
   override lazy val hashCode = super.hashCode()
   override def equals(other: Any) = other match {
diff --git a/test/files/run/bug3518.scala b/test/files/run/bug3518.scala
new file mode 100644
index 0000000000..033cc19548
--- /dev/null
+++ b/test/files/run/bug3518.scala
@@ -0,0 +1,16 @@
+object Test {
+  val r1 = 1.0 to 10.0 by 0.5
+  val r2 = 1.0 to 1.0 by 1.0
+  val r3 = 10.0 to 1.0 by -0.5
+  val r4 = 1.0 until 1.0 by 1.0
+  val r5 = 1 to 100 by 2
+
+  def main(args: Array[String]): Unit = {
+    assert(r3 forall (r1 contains _))
+    assert(r1 forall (r3 contains _))
+    assert(r2.size == 1)
+    assert(r4.isEmpty)
+    assert(List(1,3,5,97,99) forall (r5 contains _))
+    assert(List(2,4,6,98,100) forall (x => !r5.contains(x)))
+  }
+}
-- 
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