Add tasks for all the new languages

Task/Y-combinator/Swift/y-combinator-1.swift

@@ -0,0 +1,17 @@
+struct RecursiveFunc<F> {
+  let o : RecursiveFunc<F> -> F
+}
+
+func Y<A, B>(f: (A -> B) -> A -> B) -> A -> B {
+  let r = RecursiveFunc<A -> B> { w in f { w.o(w)($0) } }
+  return r.o(r)
+}
+
+let fac = Y { (f: Int -> Int) in
+  { $0 <= 1 ? 1 : $0 * f($0-1) }
+}
+let fib = Y { (f: Int -> Int) in
+  { $0 <= 2 ? 1 : f($0-1)+f($0-2) }
+}
+println("fac(5) = \(fac(5))")
+println("fib(9) = \(fib(9))")

Task/Y-combinator/Swift/y-combinator-2.swift

@@ -0,0 +1,5 @@
+func Y<A, B>(f: (A -> B) -> A -> B) -> A -> B {
+  typealias RecursiveFunc = Any -> A -> B
+  let r : RecursiveFunc = { (z: Any) in let w = z as! RecursiveFunc; return f { w(w)($0) } }
+  return r(r)
+}

Task/Y-combinator/Swift/y-combinator-3.swift

@@ -0,0 +1,3 @@
+func Y<In, Out>( f: (In->Out) -> (In->Out) ) -> (In->Out) {
+    return { x in f(Y(f))(x) }
+}