From 6e9ae187a05b1ca4fe748d8a7b45440a55ceb589 Mon Sep 17 00:00:00 2001
From: Eugene Burmako <xeno.by@gmail.com>
Date: Mon, 5 Dec 2011 17:00:55 +0100
Subject: Another test pack for reflection

Also see https://github.com/scala/scala/pull/25.
---
 test/pending/run/reify_callccinterpreter.scala | 94 ++++++++++++++++++++++++++
 1 file changed, 94 insertions(+)
 create mode 100644 test/pending/run/reify_callccinterpreter.scala

(limited to 'test/pending/run/reify_callccinterpreter.scala')

diff --git a/test/pending/run/reify_callccinterpreter.scala b/test/pending/run/reify_callccinterpreter.scala
new file mode 100644
index 0000000000..c10f4f0b4e
--- /dev/null
+++ b/test/pending/run/reify_callccinterpreter.scala
@@ -0,0 +1,94 @@
+import scala.tools.nsc.reporters._
+import scala.tools.nsc.Settings
+import reflect.runtime.Mirror.ToolBox
+
+object Test extends App {
+  val code = scala.reflect.Code.lift{
+    type Answer = Value;
+
+    /**
+     * A continuation monad.
+     */
+    case class M[A](in: (A => Answer) => Answer) {
+      def bind[B](k: A => M[B])          = M[B](c => in (a => k(a) in c))
+      def map[B](f: A => B): M[B]        = bind(x => unitM(f(x)))
+      def flatMap[B](f: A => M[B]): M[B] = bind(f)
+    }
+
+    def unitM[A](a: A) = M[A](c => c(a))
+
+    def id[A] = (x: A) => x
+    def showM(m: M[Value]): String = (m in id).toString()
+
+    def callCC[A](h: (A => M[A]) => M[A]) =
+      M[A](c => h(a => M[A](d => c(a))) in c)
+
+    type Name = String
+
+    trait Term
+    case class Var(x: Name) extends Term
+    case class Con(n: Int) extends Term
+    case class Add(l: Term, r: Term) extends Term
+    case class Lam(x: Name, body: Term) extends Term
+    case class App(fun: Term, arg: Term) extends Term
+    case class Ccc(x: Name, t: Term) extends Term
+
+    trait Value
+    case object Wrong extends Value {
+     override def toString() = "wrong"
+    }
+    case class Num(n: Int) extends Value {
+      override def toString() = n.toString()
+    }
+    case class Fun(f: Value => M[Value]) extends Value {
+      override def toString() = "<function>"
+    }
+
+    type Environment = List[Pair[Name, Value]];
+
+    def lookup(x: Name, e: Environment): M[Value] = e match {
+      case List() => unitM(Wrong)
+      case Pair(y, b) :: e1 => if (x == y) unitM(b) else lookup(x, e1)
+    }
+
+    def add(a: Value, b: Value): M[Value] = Pair(a, b) match {
+      case Pair(Num(m), Num(n)) => unitM(Num(m + n))
+      case _ => unitM(Wrong)
+    }
+
+    def apply(a: Value, b: Value): M[Value] = a match {
+      case Fun(k) => k(b)
+      case _ => unitM(Wrong)
+    }
+
+    def interp(t: Term, e: Environment): M[Value] = t match {
+      case Var(x) => lookup(x, e)
+      case Con(n) => unitM(Num(n))
+      case Add(l, r) => for (a <- interp(l, e);
+           b <- interp(r, e);
+           c <- add(a, b))
+                        yield c
+      case Lam(x, t) => unitM(Fun(a => interp(t, Pair(x, a) :: e)))
+      case App(f, t) => for (a <- interp(f, e);
+           b <- interp(t, e);
+           c <- apply(a, b))
+            yield c
+      case Ccc(x, t) => callCC(k => interp(t, Pair(x, Fun(k)) :: e))
+    }
+
+    def test(t: Term): String = showM(interp(t, List()))
+
+    val term0 = App(Lam("x", Add(Var("x"), Var("x"))), Add(Con(10), Con(11)))
+    val term1 = App(Con(1), Con(2))
+    val term2 = Add(Con(1), Ccc("k", Add(Con(2), App(Var("k"), Con(4)))))
+
+    println(test(term0))
+    println(test(term1))
+    println(test(term2))
+  };
+
+  val reporter = new ConsoleReporter(new Settings)
+  val toolbox = new ToolBox(reporter)
+  val ttree = toolbox.typeCheck(code.tree)
+  toolbox.runExpr(ttree)
+}
-- 
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