```
macro_rules! recurrence {
( a[n]: $sty:ty = $($inits:expr),+ ... $recur:expr ) => {
/* ... */
};
}
fn main() {
let fib = recurrence![a[n]: u64 = 0, 1 ... a[n-1] + a[n-2]];
for e in fib.take(10) { println!("{}", e) }
}
```

im learning macro tutorial:

https://danielkeep.github.io/quick-intro-to-macros.html

can not compile this macro,please help