Anonymous user
Man or boy test: Difference between revisions
→{{header|Rust}}
Line 2,910:
};
let b = ||(b.f)(&b);
if k <= 0 {
return x4() + x5()
} else {
return b()
}
}
pub fn main() {
println!("{}", a(10, &||1, &||-1, &||-1, &||1, &||0));
}</lang>
Another solution that gives a reference-counted function a weak reference to itself:
<lang rust>use std::cell::Cell;
use std::cell::RefCell;
use std::rc::Rc;
use std::rc::Weak;
fn a(k: i32, x1: &Fn() -> i32, x2: &Fn() -> i32, x3: &Fn() -> i32, x4: &Fn() -> i32, x5: &Fn() -> i32) -> i32 {
let weak_holder: Rc<RefCell<Weak<Fn() -> i32>>> = Rc::new(RefCell::new(Weak::<fn() -> i32>::new()));
let weak_holder2 = weak_holder.clone();
let k1 = Cell::new(k);
let b: Rc<Fn() -> i32> = Rc::new(move || {
let b = weak_holder2.borrow().upgrade().unwrap();
k1.set(k1.get() - 1);
return a(k1.get(), &*b, x1, x2, x3, x4);
});
weak_holder.replace(Rc::downgrade(&b));
if k <= 0 {
return x4() + x5()
| |||