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authorDen Shabalin <den.shabalin@gmail.com>2013-11-13 15:33:33 +0100
committerDen Shabalin <den.shabalin@gmail.com>2013-11-20 16:06:30 +0100
commitb004c3ddb38f8e690a0895a51ad0c83ff57a01e7 (patch)
tree0c31f83d2e039db4c2ead7a3280aaabc78671333 /docs/examples/monads/stateInterpreter.scala
parentc243435f113615b2f7407fbd683c93ec16c73749 (diff)
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deprecate Pair and Triple
Diffstat (limited to 'docs/examples/monads/stateInterpreter.scala')
-rw-r--r--docs/examples/monads/stateInterpreter.scala24
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)));