Function fplist::cons

pub fn cons<T>(elem: T, next: PersistentList<T>) -> PersistentList<T>

Constructs a new list by prepending one element to the another list.

The length of the overall list is increased.

use fplist::{cons, PersistentList};

let list = cons(1, cons(2, cons(3, PersistentList::new())));

assert_eq!(list.first(), Some(&1));
assert_eq!(list.len(), 3);

let list = list.rest();

assert_eq!(list.first(), Some(&2));
assert_eq!(list.len(), 2);

let list = list.rest();

assert_eq!(list.first(), Some(&3));
assert_eq!(list.len(), 1);

let list = list.rest();

assert_eq!(list.first(), None);
assert_eq!(list.len(), 0);