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109 lines
2.9 KiB
Rust
109 lines
2.9 KiB
Rust
use super::*;
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use core::iter::*;
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#[test]
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fn test_repeat() {
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let mut it = repeat(42);
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assert_eq!(it.next(), Some(42));
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assert_eq!(it.next(), Some(42));
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assert_eq!(it.next(), Some(42));
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assert_eq!(repeat(42).size_hint(), (usize::MAX, None));
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}
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#[test]
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fn test_repeat_take() {
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let mut it = repeat(42).take(3);
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assert_eq!(it.next(), Some(42));
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assert_eq!(it.next(), Some(42));
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assert_eq!(it.next(), Some(42));
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assert_eq!(it.next(), None);
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is_trusted_len(repeat(42).take(3));
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assert_eq!(repeat(42).take(3).size_hint(), (3, Some(3)));
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assert_eq!(repeat(42).take(0).size_hint(), (0, Some(0)));
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assert_eq!(repeat(42).take(usize::MAX).size_hint(), (usize::MAX, Some(usize::MAX)));
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}
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#[test]
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fn test_repeat_take_collect() {
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let v: Vec<_> = repeat(42).take(3).collect();
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assert_eq!(v, vec![42, 42, 42]);
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}
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#[test]
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fn test_repeat_with() {
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#[derive(PartialEq, Debug)]
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struct NotClone(usize);
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let mut it = repeat_with(|| NotClone(42));
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assert_eq!(it.next(), Some(NotClone(42)));
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assert_eq!(it.next(), Some(NotClone(42)));
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assert_eq!(it.next(), Some(NotClone(42)));
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assert_eq!(repeat_with(|| NotClone(42)).size_hint(), (usize::MAX, None));
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}
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#[test]
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fn test_repeat_with_take() {
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let mut it = repeat_with(|| 42).take(3);
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assert_eq!(it.next(), Some(42));
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assert_eq!(it.next(), Some(42));
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assert_eq!(it.next(), Some(42));
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assert_eq!(it.next(), None);
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is_trusted_len(repeat_with(|| 42).take(3));
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assert_eq!(repeat_with(|| 42).take(3).size_hint(), (3, Some(3)));
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assert_eq!(repeat_with(|| 42).take(0).size_hint(), (0, Some(0)));
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assert_eq!(repeat_with(|| 42).take(usize::MAX).size_hint(), (usize::MAX, Some(usize::MAX)));
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}
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#[test]
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fn test_repeat_with_take_collect() {
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let mut curr = 1;
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let v: Vec<_> = repeat_with(|| {
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let tmp = curr;
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curr *= 2;
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tmp
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})
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.take(5)
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.collect();
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assert_eq!(v, vec![1, 2, 4, 8, 16]);
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}
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#[test]
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fn test_successors() {
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let mut powers_of_10 = successors(Some(1_u16), |n| n.checked_mul(10));
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assert_eq!(powers_of_10.by_ref().collect::<Vec<_>>(), &[1, 10, 100, 1_000, 10_000]);
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assert_eq!(powers_of_10.next(), None);
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let mut empty = successors(None::<u32>, |_| unimplemented!());
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assert_eq!(empty.next(), None);
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assert_eq!(empty.next(), None);
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}
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#[test]
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fn test_once() {
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let mut it = once(42);
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assert_eq!(it.next(), Some(42));
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assert_eq!(it.next(), None);
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}
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#[test]
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fn test_once_with() {
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let count = Cell::new(0);
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let mut it = once_with(|| {
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count.set(count.get() + 1);
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42
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});
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assert_eq!(count.get(), 0);
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assert_eq!(it.next(), Some(42));
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assert_eq!(count.get(), 1);
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assert_eq!(it.next(), None);
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assert_eq!(count.get(), 1);
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assert_eq!(it.next(), None);
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assert_eq!(count.get(), 1);
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}
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#[test]
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fn test_empty() {
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let mut it = empty::<i32>();
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assert_eq!(it.next(), None);
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}
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