| use core::iter::*; |
| |
| #[test] |
| fn test_cycle() { |
| let cycle_len = 3; |
| let it = (0..).step_by(1).take(cycle_len).cycle(); |
| assert_eq!(it.size_hint(), (usize::MAX, None)); |
| for (i, x) in it.take(100).enumerate() { |
| assert_eq!(i % cycle_len, x); |
| } |
| |
| let mut it = (0..).step_by(1).take(0).cycle(); |
| assert_eq!(it.size_hint(), (0, Some(0))); |
| assert_eq!(it.next(), None); |
| |
| assert_eq!(empty::<i32>().cycle().fold(0, |acc, x| acc + x), 0); |
| |
| assert_eq!(once(1).cycle().skip(1).take(4).fold(0, |acc, x| acc + x), 4); |
| |
| assert_eq!((0..10).cycle().take(5).sum::<i32>(), 10); |
| assert_eq!((0..10).cycle().take(15).sum::<i32>(), 55); |
| assert_eq!((0..10).cycle().take(25).sum::<i32>(), 100); |
| |
| let mut iter = (0..10).cycle(); |
| iter.nth(14); |
| assert_eq!(iter.take(8).sum::<i32>(), 38); |
| |
| let mut iter = (0..10).cycle(); |
| iter.nth(9); |
| assert_eq!(iter.take(3).sum::<i32>(), 3); |
| } |