// simple factorial function using normal recursion
factorial(x) => x > 0 ? x * factorial(x-1) : 1

// simple factorial using anonymous recursion
factorial(x) => {
    f(func, val) => val > 0 ? val * func(val-1) : 1 
    return f(f, x);
}

// simple stack class
Stack(Object) :> {
    -vals = []
    +push(x) => (vals[] <- x)
    +pop() => vals[]->
    +size() => #vals
    +empty() => (vals = [])
}

my stack = Stack()
stack.push("hi")
print(stack.pop())