1 files changed, 7 insertions, 7 deletions
diff --git a/docs/examples/monads/simpleInterpreter.scala b/docs/examples/monads/simpleInterpreter.scala
index cde3a92dbb..64636749ff 100644
--- a/docs/examples/monads/simpleInterpreter.scala
+++ b/docs/examples/monads/simpleInterpreter.scala
@@ -22,7 +22,7 @@ object simpleInterpreter {
   trait Value;
   case object Wrong extends Value {
    override def toString() = "wrong"
-  } 
+  }
   case class Num(n: Int) extends Value {
     override def toString() = n.toString();
   }
@@ -30,15 +30,15 @@ object simpleInterpreter {
     override def toString() = "<function>"
   }
 
-  type Environment = List[Pair[Name, Value]];
+  type Environment = List[Tuple2[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)
+    case (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))
+  def add(a: Value, b: Value): M[Value] = (a, b) match {
+    case (Num(m), Num(n)) => unitM(Num(m + n))
     case _ => unitM(Wrong)
   }
 
@@ -54,14 +54,14 @@ object simpleInterpreter {
 			   b <- interp(r, e);
 			   c <- add(a, b))
                       yield c
-    case Lam(x, t) => unitM(Fun(a => interp(t, Pair(x, a) :: e)))
+    case Lam(x, t) => unitM(Fun(a => interp(t, (x, a) :: e)))
     case App(f, t) => for (a <- interp(f, e);
 			   b <- interp(t, e);
 			   c <- apply(a, b))
 		      yield c
   }
 
-  def test(t: Term): String = 
+  def test(t: Term): String =
     showM(interp(t, List()));
 
   val term0 = App(Lam("x", Add(Var("x"), Var("x"))), Add(Con(10), Con(11)));