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Diffstat (limited to '')
-rw-r--r-- | library/core/tests/iter/adapters/skip_while.rs | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/library/core/tests/iter/adapters/skip_while.rs b/library/core/tests/iter/adapters/skip_while.rs new file mode 100644 index 000000000..929d4f6e6 --- /dev/null +++ b/library/core/tests/iter/adapters/skip_while.rs @@ -0,0 +1,50 @@ +use core::iter::*; + +#[test] +fn test_iterator_skip_while() { + let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19]; + let ys = [15, 16, 17, 19]; + let it = xs.iter().skip_while(|&x| *x < 15); + let mut i = 0; + for x in it { + assert_eq!(*x, ys[i]); + i += 1; + } + assert_eq!(i, ys.len()); +} + +#[test] +fn test_iterator_skip_while_fold() { + let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19]; + let ys = [15, 16, 17, 19]; + let it = xs.iter().skip_while(|&x| *x < 15); + let i = it.fold(0, |i, &x| { + assert_eq!(x, ys[i]); + i + 1 + }); + assert_eq!(i, ys.len()); + + let mut it = xs.iter().skip_while(|&x| *x < 15); + assert_eq!(it.next(), Some(&ys[0])); // process skips before folding + let i = it.fold(1, |i, &x| { + assert_eq!(x, ys[i]); + i + 1 + }); + assert_eq!(i, ys.len()); +} + +#[test] +fn test_skip_while_try_fold() { + let f = &|acc, x| i32::checked_add(2 * acc, x); + fn p(&x: &i32) -> bool { + (x % 10) <= 5 + } + assert_eq!((1..20).skip_while(p).try_fold(7, f), (6..20).try_fold(7, f)); + let mut iter = (1..20).skip_while(p); + assert_eq!(iter.nth(5), Some(11)); + assert_eq!(iter.try_fold(7, f), (12..20).try_fold(7, f)); + + let mut iter = (0..50).skip_while(|&x| (x % 20) < 15); + assert_eq!(iter.try_fold(0, i8::checked_add), None); + assert_eq!(iter.next(), Some(23)); +} |