1 files changed, 12 insertions, 12 deletions

diff --git a/docs/examples/monads/stateInterpreter.scala b/docs/examples/monads/stateInterpreter.scala
index 97f3335dab..e13e9049da 100644
--- a/docs/examples/monads/stateInterpreter.scala
+++ b/docs/examples/monads/stateInterpreter.scala
@@ -4,20 +4,20 @@ object stateInterpreter {
 
   type State = Int;
 
-  val tickS = new M(s => Pair((), s + 1));
+  val tickS = new M(s => ((), s + 1));
 
-  case class M[A](in: State => Pair[A, State]) {
-    def bind[B](k: A => M[B]) = M[B]{ s0 => 
-      val Pair(a, s1) = this in s0; k(a) in s1
+  case class M[A](in: State => Tuple2[A, State]) {
+    def bind[B](k: A => M[B]) = M[B]{ s0 =>
+      val (a, s1) = this in s0; k(a) in s1
     }
     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](s => Pair(a, s));
+  def unitM[A](a: A) = M[A](s => (a, s));
 
   def showM(m: M[Value]): String = {
-    val Pair(a, s1) = m in 0;
+    val (a, s1) = m in 0;
     "Value: " + a + "; Count: " + s1
   }
 
@@ -41,15 +41,15 @@ object stateInterpreter {
     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)) => for (_ <- tickS) yield Num(m + n)
+  def add(a: Value, b: Value): M[Value] = (a, b) match {
+    case (Num(m), Num(n)) => for (_ <- tickS) yield Num(m + n)
     case _ => unitM(Wrong)
   }
 
@@ -65,14 +65,14 @@ object stateInterpreter {
 			   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)));