Major rewrite of the testing infrastructure for...

Major rewrite of the testing infrastructure for the presentation
compiler. Added several new tests that will be part of the nightly
build. Once the move to SBT is completed I will look into how to extract
the test infrastructure (as it should really not be living in the
compiler codebase). Review by dragos

1 files changed, 86 insertions, 0 deletions

diff --git a/test/files/presentation/callcc-interpreter/src/CallccInterpreter.scala b/test/files/presentation/callcc-interpreter/src/CallccInterpreter.scala
new file mode 100644
index 0000000000..ce3b996b96
--- /dev/null
+++ b/test/files/presentation/callcc-interpreter/src/CallccInterpreter.scala
@@ -0,0 +1,86 @@
+object callccInterpreter {
+
+  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]) /*?*/ = (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) /*?*/ = Pair(a, b) match {
+    case Pair(Num(m), Num(n)) => this./*!*/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 (val a <- interp(l, e);
+			   val b <- interp(r, e);
+			   val c <- add(a, b))
+                      yield c
+    case Lam(x, t) => unitM(Fun(a => interp(t, Pair(x, a) :: e)))
+    case App(f, t) => for (val a <- interp(f, e);
+			   val b <- interp(t, e);
+			   val 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)))))
+
+  def main(args: Array[String]) {
+    println(test(term0))
+    println(test(term1))
+    println(test(term2))
+  }
+}
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