1use super::*;
2
3pub struct TakeList<L: ListFn> {
4 next: L,
5 count: usize,
6}
7
8impl<L: ListFn> ListFn for TakeList<L> {
9 type Item = L::Item;
10 type End = ();
11 fn next(self) -> ListState<Self> {
12 if self.count == 0 {
13 ListState::End(())
14 } else {
15 match self.next.next() {
16 ListState::Some(some) => ListState::some(
17 some.first,
18 TakeList {
19 next: some.next,
20 count: self.count - 1,
21 },
22 ),
23 ListState::End(_) => ListState::End(()),
24 }
25 }
26 }
27}
28
29pub trait Take: ListFn {
30 fn take(self, count: usize) -> TakeList<Self> {
31 TakeList { next: self, count }
32 }
33}
34
35impl<L: ListFn> Take for L {}