diff options
Diffstat (limited to 'src/libcore/tests/iter.rs')
| -rw-r--r-- | src/libcore/tests/iter.rs | 403 |
1 files changed, 400 insertions, 3 deletions
diff --git a/src/libcore/tests/iter.rs b/src/libcore/tests/iter.rs index 3c4ea974fc9..5cac5b26d88 100644 --- a/src/libcore/tests/iter.rs +++ b/src/libcore/tests/iter.rs @@ -249,6 +249,25 @@ fn test_filter_map() { } #[test] +fn test_filter_map_fold() { + let xs = [0, 1, 2, 3, 4, 5, 6, 7, 8]; + let ys = [0*0, 2*2, 4*4, 6*6, 8*8]; + let it = xs.iter().filter_map(|&x| if x % 2 == 0 { Some(x*x) } else { None }); + let i = it.fold(0, |i, x| { + assert_eq!(x, ys[i]); + i + 1 + }); + assert_eq!(i, ys.len()); + + let it = xs.iter().filter_map(|&x| if x % 2 == 0 { Some(x*x) } else { None }); + let i = it.rfold(ys.len(), |i, x| { + assert_eq!(x, ys[i - 1]); + i - 1 + }); + assert_eq!(i, 0); +} + +#[test] fn test_iterator_enumerate() { let xs = [0, 1, 2, 3, 4, 5]; let it = xs.iter().enumerate(); @@ -282,7 +301,31 @@ fn test_iterator_enumerate_nth() { #[test] fn test_iterator_enumerate_count() { let xs = [0, 1, 2, 3, 4, 5]; - assert_eq!(xs.iter().count(), 6); + assert_eq!(xs.iter().enumerate().count(), 6); +} + +#[test] +fn test_iterator_enumerate_fold() { + let xs = [0, 1, 2, 3, 4, 5]; + let mut it = xs.iter().enumerate(); + // steal a couple to get an interesting offset + assert_eq!(it.next(), Some((0, &0))); + assert_eq!(it.next(), Some((1, &1))); + let i = it.fold(2, |i, (j, &x)| { + assert_eq!(i, j); + assert_eq!(x, xs[j]); + i + 1 + }); + assert_eq!(i, xs.len()); + + let mut it = xs.iter().enumerate(); + assert_eq!(it.next(), Some((0, &0))); + let i = it.rfold(xs.len() - 1, |i, (j, &x)| { + assert_eq!(i, j); + assert_eq!(x, xs[j]); + i - 1 + }); + assert_eq!(i, 0); } #[test] @@ -292,6 +335,25 @@ fn test_iterator_filter_count() { } #[test] +fn test_iterator_filter_fold() { + let xs = [0, 1, 2, 3, 4, 5, 6, 7, 8]; + let ys = [0, 2, 4, 6, 8]; + let it = xs.iter().filter(|&&x| x % 2 == 0); + let i = it.fold(0, |i, &x| { + assert_eq!(x, ys[i]); + i + 1 + }); + assert_eq!(i, ys.len()); + + let it = xs.iter().filter(|&&x| x % 2 == 0); + let i = it.rfold(ys.len(), |i, &x| { + assert_eq!(x, ys[i - 1]); + i - 1 + }); + assert_eq!(i, 0); +} + +#[test] fn test_iterator_peekable() { let xs = vec![0, 1, 2, 3, 4, 5]; let mut it = xs.iter().cloned().peekable(); @@ -381,6 +443,18 @@ fn test_iterator_peekable_last() { assert_eq!(it.last(), None); } +#[test] +fn test_iterator_peekable_fold() { + let xs = [0, 1, 2, 3, 4, 5]; + let mut it = xs.iter().peekable(); + assert_eq!(it.peek(), Some(&&0)); + let i = it.fold(0, |i, &x| { + assert_eq!(x, xs[i]); + i + 1 + }); + assert_eq!(i, xs.len()); +} + /// This is an iterator that follows the Iterator contract, /// but it is not fused. After having returned None once, it will start /// producing elements if .next() is called again. @@ -471,6 +545,26 @@ fn test_iterator_skip_while() { } #[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_iterator_skip() { let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19, 20, 30]; let ys = [13, 15, 16, 17, 19, 20, 30]; @@ -567,6 +661,45 @@ fn test_iterator_skip_last() { } #[test] +fn test_iterator_skip_fold() { + let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19, 20, 30]; + let ys = [13, 15, 16, 17, 19, 20, 30]; + + let it = xs.iter().skip(5); + 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(5); + 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()); + + let it = xs.iter().skip(5); + let i = it.rfold(ys.len(), |i, &x| { + let i = i - 1; + assert_eq!(x, ys[i]); + i + }); + assert_eq!(i, 0); + + let mut it = xs.iter().skip(5); + assert_eq!(it.next(), Some(&ys[0])); // process skips before folding + let i = it.rfold(ys.len(), |i, &x| { + let i = i - 1; + assert_eq!(x, ys[i]); + i + }); + assert_eq!(i, 1); + +} + +#[test] fn test_iterator_take() { let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19]; let ys = [0, 1, 2, 3, 5]; @@ -661,13 +794,22 @@ fn test_iterator_flat_map_fold() { let xs = [0, 3, 6]; let ys = [1, 2, 3, 4, 5, 6, 7]; let mut it = xs.iter().flat_map(|&x| x..x+3); - it.next(); - it.next_back(); + assert_eq!(it.next(), Some(0)); + assert_eq!(it.next_back(), Some(8)); let i = it.fold(0, |i, x| { assert_eq!(x, ys[i]); i + 1 }); assert_eq!(i, ys.len()); + + let mut it = xs.iter().flat_map(|&x| x..x+3); + assert_eq!(it.next(), Some(0)); + assert_eq!(it.next_back(), Some(8)); + let i = it.rfold(ys.len(), |i, x| { + assert_eq!(x, ys[i - 1]); + i - 1 + }); + assert_eq!(i, 0); } #[test] @@ -685,6 +827,32 @@ fn test_inspect() { } #[test] +fn test_inspect_fold() { + let xs = [1, 2, 3, 4]; + let mut n = 0; + { + let it = xs.iter().inspect(|_| n += 1); + let i = it.fold(0, |i, &x| { + assert_eq!(x, xs[i]); + i + 1 + }); + assert_eq!(i, xs.len()); + } + assert_eq!(n, xs.len()); + + let mut n = 0; + { + let it = xs.iter().inspect(|_| n += 1); + let i = it.rfold(xs.len(), |i, &x| { + assert_eq!(x, xs[i - 1]); + i - 1 + }); + assert_eq!(i, 0); + } + assert_eq!(n, xs.len()); +} + +#[test] fn test_cycle() { let cycle_len = 3; let it = (0..).step_by(1).take(cycle_len).cycle(); @@ -1242,6 +1410,31 @@ fn test_fuse_count() { } #[test] +fn test_fuse_fold() { + let xs = [0, 1, 2]; + let it = xs.iter(); // `FusedIterator` + let i = it.fuse().fold(0, |i, &x| { + assert_eq!(x, xs[i]); + i + 1 + }); + assert_eq!(i, xs.len()); + + let it = xs.iter(); // `FusedIterator` + let i = it.fuse().rfold(xs.len(), |i, &x| { + assert_eq!(x, xs[i - 1]); + i - 1 + }); + assert_eq!(i, 0); + + let it = xs.iter().scan((), |_, &x| Some(x)); // `!FusedIterator` + let i = it.fuse().fold(0, |i, x| { + assert_eq!(x, xs[i]); + i + 1 + }); + assert_eq!(i, xs.len()); +} + +#[test] fn test_once() { let mut it = once(42); assert_eq!(it.next(), Some(42)); @@ -1304,3 +1497,207 @@ fn test_step_replace_no_between() { assert_eq!(x, 1); assert_eq!(y, 5); } + +#[test] +fn test_rev_try_folds() { + let f = &|acc, x| i32::checked_add(2*acc, x); + assert_eq!((1..10).rev().try_fold(7, f), (1..10).try_rfold(7, f)); + assert_eq!((1..10).rev().try_rfold(7, f), (1..10).try_fold(7, f)); + + let a = [10, 20, 30, 40, 100, 60, 70, 80, 90]; + let mut iter = a.iter().rev(); + assert_eq!(iter.try_fold(0_i8, |acc, &x| acc.checked_add(x)), None); + assert_eq!(iter.next(), Some(&70)); + let mut iter = a.iter().rev(); + assert_eq!(iter.try_rfold(0_i8, |acc, &x| acc.checked_add(x)), None); + assert_eq!(iter.next_back(), Some(&60)); +} + +#[test] +fn test_cloned_try_folds() { + let a = [1, 2, 3, 4, 5, 6, 7, 8, 9]; + let f = &|acc, x| i32::checked_add(2*acc, x); + let f_ref = &|acc, &x| i32::checked_add(2*acc, x); + assert_eq!(a.iter().cloned().try_fold(7, f), a.iter().try_fold(7, f_ref)); + assert_eq!(a.iter().cloned().try_rfold(7, f), a.iter().try_rfold(7, f_ref)); + + let a = [10, 20, 30, 40, 100, 60, 70, 80, 90]; + let mut iter = a.iter().cloned(); + assert_eq!(iter.try_fold(0_i8, |acc, x| acc.checked_add(x)), None); + assert_eq!(iter.next(), Some(60)); + let mut iter = a.iter().cloned(); + assert_eq!(iter.try_rfold(0_i8, |acc, x| acc.checked_add(x)), None); + assert_eq!(iter.next_back(), Some(70)); +} + +#[test] +fn test_chain_try_folds() { + let c = || (0..10).chain(10..20); + + let f = &|acc, x| i32::checked_add(2*acc, x); + assert_eq!(c().try_fold(7, f), (0..20).try_fold(7, f)); + assert_eq!(c().try_rfold(7, f), (0..20).rev().try_fold(7, f)); + + let mut iter = c(); + assert_eq!(iter.position(|x| x == 5), Some(5)); + assert_eq!(iter.next(), Some(6), "stopped in front, state Both"); + assert_eq!(iter.position(|x| x == 13), Some(6)); + assert_eq!(iter.next(), Some(14), "stopped in back, state Back"); + assert_eq!(iter.try_fold(0, |acc, x| Some(acc+x)), Some((15..20).sum())); + + let mut iter = c().rev(); // use rev to access try_rfold + assert_eq!(iter.position(|x| x == 15), Some(4)); + assert_eq!(iter.next(), Some(14), "stopped in back, state Both"); + assert_eq!(iter.position(|x| x == 5), Some(8)); + assert_eq!(iter.next(), Some(4), "stopped in front, state Front"); + assert_eq!(iter.try_fold(0, |acc, x| Some(acc+x)), Some((0..4).sum())); + + let mut iter = c(); + iter.by_ref().rev().nth(14); // skip the last 15, ending in state Front + assert_eq!(iter.try_fold(7, f), (0..5).try_fold(7, f)); + + let mut iter = c(); + iter.nth(14); // skip the first 15, ending in state Back + assert_eq!(iter.try_rfold(7, f), (15..20).try_rfold(7, f)); +} + +#[test] +fn test_map_try_folds() { + let f = &|acc, x| i32::checked_add(2*acc, x); + assert_eq!((0..10).map(|x| x+3).try_fold(7, f), (3..13).try_fold(7, f)); + assert_eq!((0..10).map(|x| x+3).try_rfold(7, f), (3..13).try_rfold(7, f)); + + let mut iter = (0..40).map(|x| x+10); + 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(46)); +} + +#[test] +fn test_filter_try_folds() { + fn p(&x: &i32) -> bool { 0 <= x && x < 10 } + let f = &|acc, x| i32::checked_add(2*acc, x); + assert_eq!((-10..20).filter(p).try_fold(7, f), (0..10).try_fold(7, f)); + assert_eq!((-10..20).filter(p).try_rfold(7, f), (0..10).try_rfold(7, f)); + + let mut iter = (0..40).filter(|&x| x % 2 == 1); + assert_eq!(iter.try_fold(0, i8::checked_add), None); + assert_eq!(iter.next(), Some(25)); + assert_eq!(iter.try_rfold(0, i8::checked_add), None); + assert_eq!(iter.next_back(), Some(31)); +} + +#[test] +fn test_filter_map_try_folds() { + let mp = &|x| if 0 <= x && x < 10 { Some(x*2) } else { None }; + let f = &|acc, x| i32::checked_add(2*acc, x); + assert_eq!((-9..20).filter_map(mp).try_fold(7, f), (0..10).map(|x| 2*x).try_fold(7, f)); + assert_eq!((-9..20).filter_map(mp).try_rfold(7, f), (0..10).map(|x| 2*x).try_rfold(7, f)); + + let mut iter = (0..40).filter_map(|x| if x%2 == 1 { None } else { Some(x*2 + 10) }); + assert_eq!(iter.try_fold(0, i8::checked_add), None); + assert_eq!(iter.next(), Some(38)); + assert_eq!(iter.try_rfold(0, i8::checked_add), None); + assert_eq!(iter.next_back(), Some(78)); +} + +#[test] +fn test_enumerate_try_folds() { + let f = &|acc, (i, x)| usize::checked_add(2*acc, x/(i+1) + i); + assert_eq!((9..18).enumerate().try_fold(7, f), (0..9).map(|i| (i, i+9)).try_fold(7, f)); + assert_eq!((9..18).enumerate().try_rfold(7, f), (0..9).map(|i| (i, i+9)).try_rfold(7, f)); + + let mut iter = (100..200).enumerate(); + let f = &|acc, (i, x)| u8::checked_add(acc, u8::checked_div(x, i as u8 + 1)?); + assert_eq!(iter.try_fold(0, f), None); + assert_eq!(iter.next(), Some((7, 107))); + assert_eq!(iter.try_rfold(0, f), None); + assert_eq!(iter.next_back(), Some((11, 111))); +} + +#[test] +fn test_peek_try_fold() { + let f = &|acc, x| i32::checked_add(2*acc, x); + assert_eq!((1..20).peekable().try_fold(7, f), (1..20).try_fold(7, f)); + let mut iter = (1..20).peekable(); + assert_eq!(iter.peek(), Some(&1)); + assert_eq!(iter.try_fold(7, f), (1..20).try_fold(7, f)); + + let mut iter = [100, 20, 30, 40, 50, 60, 70].iter().cloned().peekable(); + assert_eq!(iter.peek(), Some(&100)); + assert_eq!(iter.try_fold(0, i8::checked_add), None); + assert_eq!(iter.peek(), Some(&40)); +} + +#[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)); +} + +#[test] +fn test_take_while_folds() { + let f = &|acc, x| i32::checked_add(2*acc, x); + assert_eq!((1..20).take_while(|&x| x != 10).try_fold(7, f), (1..10).try_fold(7, f)); + let mut iter = (1..20).take_while(|&x| x != 10); + assert_eq!(iter.try_fold(0, |x, y| Some(x+y)), Some((1..10).sum())); + assert_eq!(iter.next(), None, "flag should be set"); + let iter = (1..20).take_while(|&x| x != 10); + assert_eq!(iter.fold(0, |x, y| x+y), (1..10).sum()); + + let mut iter = (10..50).take_while(|&x| x != 40); + assert_eq!(iter.try_fold(0, i8::checked_add), None); + assert_eq!(iter.next(), Some(20)); +} + +#[test] +fn test_skip_try_folds() { + let f = &|acc, x| i32::checked_add(2*acc, x); + assert_eq!((1..20).skip(9).try_fold(7, f), (10..20).try_fold(7, f)); + assert_eq!((1..20).skip(9).try_rfold(7, f), (10..20).try_rfold(7, f)); + + let mut iter = (0..30).skip(10); + 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)); +} + +#[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)); +} + +#[test] +fn test_flat_map_try_folds() { + let f = &|acc, x| i32::checked_add(acc*2/3, x); + let mr = &|x| (5*x)..(5*x + 5); + assert_eq!((0..10).flat_map(mr).try_fold(7, f), (0..50).try_fold(7, f)); + assert_eq!((0..10).flat_map(mr).try_rfold(7, f), (0..50).try_rfold(7, f)); + let mut iter = (0..10).flat_map(mr); + iter.next(); iter.next_back(); // have front and back iters in progress + assert_eq!(iter.try_rfold(7, f), (1..49).try_rfold(7, f)); + + let mut iter = (0..10).flat_map(|x| (4*x)..(4*x + 4)); + assert_eq!(iter.try_fold(0, i8::checked_add), None); + assert_eq!(iter.next(), Some(17)); + assert_eq!(iter.try_rfold(0, i8::checked_add), None); + assert_eq!(iter.next_back(), Some(35)); +} |