use super::*;
pub struct TakeList<L: ListFn> {
next: L,
count: usize,
}
impl<L: ListFn> ListFn for TakeList<L> {
type Item = L::Item;
type End = ();
fn next(self) -> ListState<Self> {
if self.count == 0 {
ListState::End(())
} else {
match self.next.next() {
ListState::Some(some) => ListState::some(
some.first,
TakeList {
next: some.next,
count: self.count - 1,
},
),
ListState::End(_) => ListState::End(()),
}
}
}
}
pub trait Take: ListFn {
fn take(self, count: usize) -> TakeList<Self> {
TakeList { next: self, count }
}
}
impl<L: ListFn> Take for L {}