From df50e05006b43b007c2587549030d24b5c154398 Mon Sep 17 00:00:00 2001
From: Gilles Dubochet <gilles.dubochet@epfl.ch>
Date: Fri, 16 Dec 2005 18:29:42 +0000
Subject: 'test-nsc' has been moved to 'test'.

---
 test/files/run/Course-2002-10.scala | 136 ++++++++++++++++++++++++++++++++++++
 1 file changed, 136 insertions(+)
 create mode 100644 test/files/run/Course-2002-10.scala

(limited to 'test/files/run/Course-2002-10.scala')

diff --git a/test/files/run/Course-2002-10.scala b/test/files/run/Course-2002-10.scala
new file mode 100644
index 0000000000..e634309018
--- /dev/null
+++ b/test/files/run/Course-2002-10.scala
@@ -0,0 +1,136 @@
+//############################################################################
+// Programmation IV - 2002 - Week 10
+//############################################################################
+// $Id$
+
+import java.lang.System; // to avoid name clash with .NET's library
+
+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 => {System.out.println("fib("+i+") = "+n); i=i+1});
+    System.out.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 at 0;
+    val n   = s at 1;
+    val np1 = s at 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) {
+      System.out.print("pi("+i+") = ");
+      System.out.print(str(pi0.at(i)) + ", ");
+      System.out.print(str(pi1.at(i)) + ", ");
+      System.out.print(str(pi2.at(i)) + "\n");
+      i = i + 1;
+    }
+    System.out.print("pi    = ");
+    System.out.print(str(Math.PI) + ", ");
+    System.out.print(str(Math.PI) + ", ");
+    System.out.print(str(Math.PI) + "\n");
+    System.out.println();
+    i = 0;
+    while (i < 10) {
+      System.out.print("ln("+i+") = ");
+      System.out.print(str(ln0.at(i)) + ", ");
+      System.out.print(str(ln1.at(i)) + ", ");
+      System.out.print(str(ln2.at(i)) + "\n");
+      i = i + 1;
+    }
+    System.out.print("ln    = ");
+    System.out.print(str(Math.log(2)) + ", ");
+    System.out.print(str(Math.log(2)) + ", ");
+    System.out.print(str(Math.log(2)) + "\n");
+    System.out.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);
+    System.out.print("prime numbers:");
+    while (i.hasNext) { System.out.print(" " + i.next); }
+    System.out.println();
+  }
+}
+
+//############################################################################
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    M0.test;
+    M1.test;
+    M2.test;
+    ()
+  }
+}
+
+//############################################################################
-- 
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