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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
commit | 698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch) | |
tree | 173a775858bd501c378080a10dca74132f05bc50 /library/core/tests/iter/adapters/take.rs | |
parent | Initial commit. (diff) | |
download | rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip |
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'library/core/tests/iter/adapters/take.rs')
-rw-r--r-- | library/core/tests/iter/adapters/take.rs | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/library/core/tests/iter/adapters/take.rs b/library/core/tests/iter/adapters/take.rs new file mode 100644 index 000000000..bfb659f0a --- /dev/null +++ b/library/core/tests/iter/adapters/take.rs @@ -0,0 +1,148 @@ +use core::iter::*; + +#[test] +fn test_iterator_take() { + let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19]; + let ys = [0, 1, 2, 3, 5]; + + let mut it = xs.iter().take(ys.len()); + let mut i = 0; + assert_eq!(it.len(), ys.len()); + while let Some(&x) = it.next() { + assert_eq!(x, ys[i]); + i += 1; + assert_eq!(it.len(), ys.len() - i); + } + assert_eq!(i, ys.len()); + assert_eq!(it.len(), 0); + + let mut it = xs.iter().take(ys.len()); + let mut i = 0; + assert_eq!(it.len(), ys.len()); + while let Some(&x) = it.next_back() { + i += 1; + assert_eq!(x, ys[ys.len() - i]); + assert_eq!(it.len(), ys.len() - i); + } + assert_eq!(i, ys.len()); + assert_eq!(it.len(), 0); +} + +#[test] +fn test_iterator_take_nth() { + let xs = [0, 1, 2, 4, 5]; + let mut it = xs.iter(); + { + let mut take = it.by_ref().take(3); + let mut i = 0; + while let Some(&x) = take.nth(0) { + assert_eq!(x, i); + i += 1; + } + } + assert_eq!(it.nth(1), Some(&5)); + assert_eq!(it.nth(0), None); + + let xs = [0, 1, 2, 3, 4]; + let mut it = xs.iter().take(7); + let mut i = 1; + while let Some(&x) = it.nth(1) { + assert_eq!(x, i); + i += 2; + } +} + +#[test] +fn test_iterator_take_nth_back() { + let xs = [0, 1, 2, 4, 5]; + let mut it = xs.iter(); + { + let mut take = it.by_ref().take(3); + let mut i = 0; + while let Some(&x) = take.nth_back(0) { + i += 1; + assert_eq!(x, 3 - i); + } + } + assert_eq!(it.nth_back(0), None); + + let xs = [0, 1, 2, 3, 4]; + let mut it = xs.iter().take(7); + assert_eq!(it.nth_back(1), Some(&3)); + assert_eq!(it.nth_back(1), Some(&1)); + assert_eq!(it.nth_back(1), None); +} + +#[test] +fn test_take_advance_by() { + let mut take = (0..10).take(3); + assert_eq!(take.advance_by(2), Ok(())); + assert_eq!(take.next(), Some(2)); + assert_eq!(take.advance_by(1), Err(0)); + + assert_eq!((0..0).take(10).advance_by(0), Ok(())); + assert_eq!((0..0).take(10).advance_by(1), Err(0)); + assert_eq!((0..10).take(4).advance_by(5), Err(4)); + + let mut take = (0..10).take(3); + assert_eq!(take.advance_back_by(2), Ok(())); + assert_eq!(take.next(), Some(0)); + assert_eq!(take.advance_back_by(1), Err(0)); + + assert_eq!((0..2).take(1).advance_back_by(10), Err(1)); + assert_eq!((0..0).take(1).advance_back_by(1), Err(0)); + assert_eq!((0..0).take(1).advance_back_by(0), Ok(())); + assert_eq!((0..usize::MAX).take(100).advance_back_by(usize::MAX), Err(100)); +} + +#[test] +fn test_iterator_take_short() { + let xs = [0, 1, 2, 3]; + + let mut it = xs.iter().take(5); + let mut i = 0; + assert_eq!(it.len(), xs.len()); + while let Some(&x) = it.next() { + assert_eq!(x, xs[i]); + i += 1; + assert_eq!(it.len(), xs.len() - i); + } + assert_eq!(i, xs.len()); + assert_eq!(it.len(), 0); + + let mut it = xs.iter().take(5); + let mut i = 0; + assert_eq!(it.len(), xs.len()); + while let Some(&x) = it.next_back() { + i += 1; + assert_eq!(x, xs[xs.len() - i]); + assert_eq!(it.len(), xs.len() - i); + } + assert_eq!(i, xs.len()); + assert_eq!(it.len(), 0); +} + +#[test] +fn test_take_try_folds() { + let f = &|acc, x| i32::checked_add(2 * acc, x); + assert_eq!((10..30).take(10).try_fold(7, f), (10..20).try_fold(7, f)); + assert_eq!((10..30).take(10).try_rfold(7, f), (10..20).try_rfold(7, f)); + + let mut iter = (10..30).take(20); + assert_eq!(iter.try_fold(0, i8::checked_add), None); + assert_eq!(iter.next(), Some(20)); + assert_eq!(iter.try_rfold(0, i8::checked_add), None); + assert_eq!(iter.next_back(), Some(24)); + + let mut iter = (2..20).take(3); + assert_eq!(iter.try_for_each(Err), Err(2)); + assert_eq!(iter.try_for_each(Err), Err(3)); + assert_eq!(iter.try_for_each(Err), Err(4)); + assert_eq!(iter.try_for_each(Err), Ok(())); + + let mut iter = (2..20).take(3).rev(); + assert_eq!(iter.try_for_each(Err), Err(4)); + assert_eq!(iter.try_for_each(Err), Err(3)); + assert_eq!(iter.try_for_each(Err), Err(2)); + assert_eq!(iter.try_for_each(Err), Ok(())); +} |