Avoid spurious StaleSymbol error in <refinement> members

Refinement classes and their members could give spurious stale symbol errors if the
symbol is loaded in a different run than the classfile containing it. The problem
is that refinement classes do not form part of the scope of their owners. The fix
assumes that refinement classes are always "stillValid".

1 files changed, 135 insertions, 0 deletions

diff --git a/tests/run/Course-2002-10.scala b/tests/run/Course-2002-10.scala
new file mode 100644
index 000000000..4cfa1deb0
--- /dev/null
+++ b/tests/run/Course-2002-10.scala
@@ -0,0 +1,135 @@
+//############################################################################
+// Programmation IV - 2002 - Week 10
+//############################################################################
+
+import math.{Pi, log}
+
+object M0 {
+
+  def addStream (s1: Stream[Int], s2: Stream[Int]): Stream[Int] =
+    Stream.cons(s1.head + s2.head, addStream(s1.tail, s2.tail));
+
+  val fib: Stream[Int] =
+    Stream.cons(0, Stream.cons(1, addStream(this.fib, this.fib.tail)));
+
+  def test = {
+    var i = 0;
+    fib.take(20).foreach(n => {Console.println("fib("+i+") = "+n); i=i+1});
+    Console.println;
+  }
+}
+
+//############################################################################
+
+object M1 {
+
+  def scale(x: Double, s: Stream[Double]): Stream[Double] =
+    s map { e: Double => e*x }
+
+  def partialSums(s: Stream[Double]): Stream[Double] =
+    Stream.cons(s.head, partialSums(s.tail) map (x => x + s.head));
+
+  def euler(s: Stream[Double]): Stream[Double] = {
+    val nm1 = s apply 0;
+    val n   = s apply 1;
+    val np1 = s apply 2;
+    Stream.cons(np1 - ((np1 - n)*(np1 - n) / (nm1 - 2*n + np1)),euler(s.tail))
+  };
+
+  def better(s: Stream[Double], transform: Stream[Double] => Stream[Double])
+    : Stream[Stream[Double]] =
+    Stream.cons(s, better(transform(s), transform));
+
+  def veryGood(s: Stream[Double], transform: Stream[Double] => Stream[Double])
+    : Stream[Double] =
+    better(s, transform) map (x => x.head);
+
+  def lnSummands(n: Double): Stream[Double] =
+    Stream.cons(1.0 / n, lnSummands(n + 1.0) map { x: Double => -x })
+
+  var ln0 = partialSums(lnSummands(1.0));
+  var ln1 = euler(ln0);
+  var ln2 = veryGood(ln0, euler);
+
+  def piSummands(n: Double): Stream[Double] =
+    Stream.cons(1.0 / n, piSummands(n + 2.0) map { x: Double => -x })
+
+  var pi0 = scale(4.0, partialSums(piSummands(1.0)));
+  var pi1 = euler(pi0);
+  var pi2 = veryGood(pi0, euler);
+
+  def pad(s: String, n: Int): String =
+    if (n <= 0) s.substring(0, s.length() + n)
+    else pad(s + " ", n - 1);
+  def str(d: Double) = { val s = d.toString(); pad(s, 18 - s.length()) };
+
+  def test = {
+    var i = 0;
+    while (i < 10) {
+      Console.print("pi("+i+") = ");
+      Console.print(str(pi0.apply(i)) + ", ");
+      Console.print(str(pi1.apply(i)) + ", ");
+      Console.print(str(pi2.apply(i)) + "\n");
+      i = i + 1;
+    }
+    Console.print("pi    = ");
+    Console.print(str(Pi) + ", ");
+    Console.print(str(Pi) + ", ");
+    Console.print(str(Pi) + "\n");
+    Console.println;
+    i = 0;
+    while (i < 10) {
+      Console.print("ln("+i+") = ");
+      Console.print(str(ln0.apply(i)) + ", ");
+      Console.print(str(ln1.apply(i)) + ", ");
+      Console.print(str(ln2.apply(i)) + "\n");
+      i = i + 1;
+    }
+    Console.print("ln    = ");
+    Console.print(str(log(2)) + ", ");
+    Console.print(str(log(2)) + ", ");
+    Console.print(str(log(2)) + "\n");
+    Console.println;
+  }
+}
+
+//############################################################################
+
+object M2 {
+
+  class IntIterator(start: Int) extends Iterator[Int] {
+    var current: Int = start;
+    def hasNext = true;
+    def next = { current = current + 1; current - 1 };
+  }
+
+  class PrimeIterator() extends Iterator[Int] {
+    var current: Iterator[Int] = new IntIterator(2);
+    def hasNext = true;
+    def next = {
+      val p = current.next;
+      current = current filter { x => !((x % p) == 0) };
+      p
+    }
+  }
+
+  def test = {
+    val i = (new PrimeIterator()).take(30);
+    Console.print("prime numbers:");
+    while (i.hasNext) { Console.print(" " + i.next); }
+    Console.println;
+  }
+}
+
+//############################################################################
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    M0.test;
+    M1.test;
+    M2.test;
+    ()
+  }
+}
+
+//############################################################################