//############################################################################
// Tail Calls
//############################################################################
// $Id$
//############################################################################
object Object {
def fun1(n: Int, v: Int): Int =
if (n == 0) v else fun1(n - 1, v - 1);
def fun2[T](n: Int, v: Int): Int =
if (n == 0) v else fun2[T](n - 1, v - 1);
def fun3[T](n: Int, v: Int, ls: List[T]): Int =
if (n == 0) v else fun3(n - 1, v - 1, ls);
// !!! return in non-tail-call position
// !!! local functions
// !!! functions in objects in classes
// !!! non-same-instance calls
// !!! non-same-type calls
}
//############################################################################
final class Final {
def fun1(n: Int, v: Int): Int =
if (n == 0) v else fun1(n - 1, v - 1);
}
//############################################################################
class Class {
final def fun1(n: Int, v: Int): Int =
if (n == 0) v else fun1(n - 1, v - 1);
def fun2(n: Int, v: Int): Int = funA(n, v);
private def funA(n: Int, v: Int): Int =
if (n == 0) v else funA(n - 1, v - 1);
def fun3(n: Int, v: Int): Int = fun4(n, v);
def fun4(n: Int, v: Int): Int =
if (n == 0) v else fun4(n - 1, v - 1);
}
class SubClass extends Class {
override def fun4(n: Int, v: Int): Int = v;
}
//############################################################################
sealed class Sealed {
def fun1(n: Int, v: Int): Int =
if (n == 0) v else fun1(n - 1, v - 1);
}
//############################################################################
// class SubSealed extends Sealed {
// override def fun1(n: Int, v: Int): Int = v;
// }
//############################################################################
object Test {
def check_success(name: String, def closure: Int, expected: Int): Unit = {
import java.lang.System;
System.out.print("test " + name);
try {
val actual: Int = closure;
if (actual == expected) {
System.out.print(" was successful");
} else {
System.out.print(" failed: expected "+ expected +", found "+ actual);
}
} catch {
case exception: Throwable => {
System.out.print(" raised exception " + exception);
}
}
System.out.println();
}
def main(args: Array[String]) = {
if (args.length < 1) throw new Error("missing target argument");
val min = 16;
val max = args(0) match {
case "jvm" => 2 * 1024 * 1024
case "int" => 64 * 1024
case "msil" => 2 * 1024 * 1024
case target => throw new Error("unknown target '" + target + "'")
}
check_success("Object.fun1", Object.fun1(max, max), 0);
check_success("Object.fun2", Object.fun2(max, max), 0);
check_success("Object.fun3", Object.fun3(max, max, List(1)), 0);
val f: Final = new Final;
check_success("Class.fun1", f.fun1(max, max), 0);
val c: Class = new SubClass;
check_success("Class.fun1", c.fun1(max, max), 0);
check_success("Class.fun2", c.fun2(max, max), 0);
check_success("Class.fun3", c.fun3(min, min), min);
check_success("Class.fun4", c.fun4(min, min), min);
// !!!
// val s: Sealed = new SubSealed;
// check_success("Sealed.fun1", s.fun1(min, min), min);
}
}
//############################################################################
