| //! The purpose of these tests is to cover corner cases of iterators |
| //! and adaptors. |
| //! |
| //! In particular we test the tedious size_hint and exact size correctness. |
| |
| #![allow(deprecated, unstable_name_collisions)] |
| |
| use itertools::free::{ |
| cloned, enumerate, multipeek, peek_nth, put_back, put_back_n, rciter, zip, zip_eq, |
| }; |
| use itertools::Itertools; |
| use itertools::{iproduct, izip, multizip, EitherOrBoth}; |
| use quickcheck as qc; |
| use std::cmp::{max, min, Ordering}; |
| use std::collections::{HashMap, HashSet}; |
| use std::default::Default; |
| use std::num::Wrapping; |
| use std::ops::Range; |
| |
| use quickcheck::TestResult; |
| use rand::seq::SliceRandom; |
| use rand::Rng; |
| |
| /// Trait for size hint modifier types |
| trait HintKind: Copy + Send + qc::Arbitrary { |
| fn loosen_bounds(&self, org_hint: (usize, Option<usize>)) -> (usize, Option<usize>); |
| } |
| |
| /// Exact size hint variant that leaves hints unchanged |
| #[derive(Clone, Copy, Debug)] |
| struct Exact {} |
| |
| impl HintKind for Exact { |
| fn loosen_bounds(&self, org_hint: (usize, Option<usize>)) -> (usize, Option<usize>) { |
| org_hint |
| } |
| } |
| |
| impl qc::Arbitrary for Exact { |
| fn arbitrary<G: qc::Gen>(_: &mut G) -> Self { |
| Self {} |
| } |
| } |
| |
| /// Inexact size hint variant to simulate imprecise (but valid) size hints |
| /// |
| /// Will always decrease the lower bound and increase the upper bound |
| /// of the size hint by set amounts. |
| #[derive(Clone, Copy, Debug)] |
| struct Inexact { |
| underestimate: usize, |
| overestimate: usize, |
| } |
| |
| impl HintKind for Inexact { |
| fn loosen_bounds(&self, org_hint: (usize, Option<usize>)) -> (usize, Option<usize>) { |
| let (org_lower, org_upper) = org_hint; |
| ( |
| org_lower.saturating_sub(self.underestimate), |
| org_upper.and_then(move |x| x.checked_add(self.overestimate)), |
| ) |
| } |
| } |
| |
| impl qc::Arbitrary for Inexact { |
| fn arbitrary<G: qc::Gen>(g: &mut G) -> Self { |
| let ue_value = usize::arbitrary(g); |
| let oe_value = usize::arbitrary(g); |
| // Compensate for quickcheck using extreme values too rarely |
| let ue_choices = &[0, ue_value, usize::MAX]; |
| let oe_choices = &[0, oe_value, usize::MAX]; |
| Self { |
| underestimate: *ue_choices.choose(g).unwrap(), |
| overestimate: *oe_choices.choose(g).unwrap(), |
| } |
| } |
| |
| fn shrink(&self) -> Box<dyn Iterator<Item = Self>> { |
| let underestimate_value = self.underestimate; |
| let overestimate_value = self.overestimate; |
| Box::new(underestimate_value.shrink().flat_map(move |ue_value| { |
| overestimate_value.shrink().map(move |oe_value| Self { |
| underestimate: ue_value, |
| overestimate: oe_value, |
| }) |
| })) |
| } |
| } |
| |
| /// Our base iterator that we can impl Arbitrary for |
| /// |
| /// By default we'll return inexact bounds estimates for size_hint |
| /// to make tests harder to pass. |
| /// |
| /// NOTE: Iter is tricky and is not fused, to help catch bugs. |
| /// At the end it will return None once, then return Some(0), |
| /// then return None again. |
| #[derive(Clone, Debug)] |
| struct Iter<T, SK: HintKind = Inexact> { |
| iterator: Range<T>, |
| // fuse/done flag |
| fuse_flag: i32, |
| hint_kind: SK, |
| } |
| |
| impl<T, HK> Iter<T, HK> |
| where |
| HK: HintKind, |
| { |
| fn new(it: Range<T>, hint_kind: HK) -> Self { |
| Self { |
| iterator: it, |
| fuse_flag: 0, |
| hint_kind, |
| } |
| } |
| } |
| |
| impl<T, HK> Iterator for Iter<T, HK> |
| where |
| Range<T>: Iterator, |
| <Range<T> as Iterator>::Item: Default, |
| HK: HintKind, |
| { |
| type Item = <Range<T> as Iterator>::Item; |
| |
| fn next(&mut self) -> Option<Self::Item> { |
| let elt = self.iterator.next(); |
| if elt.is_none() { |
| self.fuse_flag += 1; |
| // check fuse flag |
| if self.fuse_flag == 2 { |
| return Some(Default::default()); |
| } |
| } |
| elt |
| } |
| |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| let org_hint = self.iterator.size_hint(); |
| self.hint_kind.loosen_bounds(org_hint) |
| } |
| } |
| |
| impl<T, HK> DoubleEndedIterator for Iter<T, HK> |
| where |
| Range<T>: DoubleEndedIterator, |
| <Range<T> as Iterator>::Item: Default, |
| HK: HintKind, |
| { |
| fn next_back(&mut self) -> Option<Self::Item> { |
| self.iterator.next_back() |
| } |
| } |
| |
| impl<T> ExactSizeIterator for Iter<T, Exact> |
| where |
| Range<T>: ExactSizeIterator, |
| <Range<T> as Iterator>::Item: Default, |
| { |
| } |
| |
| impl<T, HK> qc::Arbitrary for Iter<T, HK> |
| where |
| T: qc::Arbitrary, |
| HK: HintKind, |
| { |
| fn arbitrary<G: qc::Gen>(g: &mut G) -> Self { |
| Self::new(T::arbitrary(g)..T::arbitrary(g), HK::arbitrary(g)) |
| } |
| |
| fn shrink(&self) -> Box<dyn Iterator<Item = Self>> { |
| let r = self.iterator.clone(); |
| let hint_kind = self.hint_kind; |
| Box::new(r.start.shrink().flat_map(move |a| { |
| r.end |
| .shrink() |
| .map(move |b| Self::new(a.clone()..b, hint_kind)) |
| })) |
| } |
| } |
| |
| /// A meta-iterator which yields `Iter<i32>`s whose start/endpoints are |
| /// increased or decreased linearly on each iteration. |
| #[derive(Clone, Debug)] |
| struct ShiftRange<HK = Inexact> { |
| range_start: i32, |
| range_end: i32, |
| start_step: i32, |
| end_step: i32, |
| iter_count: u32, |
| hint_kind: HK, |
| } |
| |
| impl<HK> Iterator for ShiftRange<HK> |
| where |
| HK: HintKind, |
| { |
| type Item = Iter<i32, HK>; |
| |
| fn next(&mut self) -> Option<Self::Item> { |
| if self.iter_count == 0 { |
| return None; |
| } |
| |
| let iter = Iter::new(self.range_start..self.range_end, self.hint_kind); |
| |
| self.range_start += self.start_step; |
| self.range_end += self.end_step; |
| self.iter_count -= 1; |
| |
| Some(iter) |
| } |
| } |
| |
| impl ExactSizeIterator for ShiftRange<Exact> {} |
| |
| impl<HK> qc::Arbitrary for ShiftRange<HK> |
| where |
| HK: HintKind, |
| { |
| fn arbitrary<G: qc::Gen>(g: &mut G) -> Self { |
| const MAX_STARTING_RANGE_DIFF: i32 = 32; |
| const MAX_STEP_MODULO: i32 = 8; |
| const MAX_ITER_COUNT: u32 = 3; |
| |
| let range_start = qc::Arbitrary::arbitrary(g); |
| let range_end = range_start + g.gen_range(0, MAX_STARTING_RANGE_DIFF + 1); |
| let start_step = g.gen_range(-MAX_STEP_MODULO, MAX_STEP_MODULO + 1); |
| let end_step = g.gen_range(-MAX_STEP_MODULO, MAX_STEP_MODULO + 1); |
| let iter_count = g.gen_range(0, MAX_ITER_COUNT + 1); |
| let hint_kind = qc::Arbitrary::arbitrary(g); |
| |
| Self { |
| range_start, |
| range_end, |
| start_step, |
| end_step, |
| iter_count, |
| hint_kind, |
| } |
| } |
| } |
| |
| fn correct_count<I, F>(get_it: F) -> bool |
| where |
| I: Iterator, |
| F: Fn() -> I, |
| { |
| let mut counts = vec![get_it().count()]; |
| |
| 'outer: loop { |
| let mut it = get_it(); |
| |
| for _ in 0..(counts.len() - 1) { |
| #[allow(clippy::manual_assert)] |
| if it.next().is_none() { |
| panic!("Iterator shouldn't be finished, may not be deterministic"); |
| } |
| } |
| |
| if it.next().is_none() { |
| break 'outer; |
| } |
| |
| counts.push(it.count()); |
| } |
| |
| let total_actual_count = counts.len() - 1; |
| |
| for (i, returned_count) in counts.into_iter().enumerate() { |
| let actual_count = total_actual_count - i; |
| if actual_count != returned_count { |
| println!( |
| "Total iterations: {} True count: {} returned count: {}", |
| i, actual_count, returned_count |
| ); |
| |
| return false; |
| } |
| } |
| |
| true |
| } |
| |
| fn correct_size_hint<I: Iterator>(mut it: I) -> bool { |
| // record size hint at each iteration |
| let initial_hint = it.size_hint(); |
| let mut hints = Vec::with_capacity(initial_hint.0 + 1); |
| hints.push(initial_hint); |
| while let Some(_) = it.next() { |
| hints.push(it.size_hint()) |
| } |
| |
| let mut true_count = hints.len(); // start off +1 too much |
| |
| // check all the size hints |
| for &(low, hi) in &hints { |
| true_count -= 1; |
| if low > true_count || (hi.is_some() && hi.unwrap() < true_count) { |
| println!("True size: {:?}, size hint: {:?}", true_count, (low, hi)); |
| //println!("All hints: {:?}", hints); |
| return false; |
| } |
| } |
| true |
| } |
| |
| fn exact_size<I: ExactSizeIterator>(mut it: I) -> bool { |
| // check every iteration |
| let (mut low, mut hi) = it.size_hint(); |
| if Some(low) != hi { |
| return false; |
| } |
| while let Some(_) = it.next() { |
| let (xlow, xhi) = it.size_hint(); |
| if low != xlow + 1 { |
| return false; |
| } |
| low = xlow; |
| hi = xhi; |
| if Some(low) != hi { |
| return false; |
| } |
| } |
| let (low, hi) = it.size_hint(); |
| low == 0 && hi == Some(0) |
| } |
| |
| // Exact size for this case, without ExactSizeIterator |
| fn exact_size_for_this<I: Iterator>(mut it: I) -> bool { |
| // check every iteration |
| let (mut low, mut hi) = it.size_hint(); |
| if Some(low) != hi { |
| return false; |
| } |
| while let Some(_) = it.next() { |
| let (xlow, xhi) = it.size_hint(); |
| if low != xlow + 1 { |
| return false; |
| } |
| low = xlow; |
| hi = xhi; |
| if Some(low) != hi { |
| return false; |
| } |
| } |
| let (low, hi) = it.size_hint(); |
| low == 0 && hi == Some(0) |
| } |
| |
| /* |
| * NOTE: Range<i8> is broken! |
| * (all signed ranges are) |
| #[quickcheck] |
| fn size_range_i8(a: Iter<i8>) -> bool { |
| exact_size(a) |
| } |
| |
| #[quickcheck] |
| fn size_range_i16(a: Iter<i16>) -> bool { |
| exact_size(a) |
| } |
| |
| #[quickcheck] |
| fn size_range_u8(a: Iter<u8>) -> bool { |
| exact_size(a) |
| } |
| */ |
| |
| macro_rules! quickcheck { |
| // accept several property function definitions |
| // The property functions can use pattern matching and `mut` as usual |
| // in the function arguments, but the functions can not be generic. |
| {$($(#$attr:tt)* fn $fn_name:ident($($arg:tt)*) -> $ret:ty { $($code:tt)* })*} => ( |
| $( |
| #[test] |
| $(#$attr)* |
| fn $fn_name() { |
| fn prop($($arg)*) -> $ret { |
| $($code)* |
| } |
| ::quickcheck::quickcheck(quickcheck!(@fn prop [] $($arg)*)); |
| } |
| )* |
| ); |
| // parse argument list (with patterns allowed) into prop as fn(_, _) -> _ |
| (@fn $f:ident [$($t:tt)*]) => { |
| $f as fn($($t),*) -> _ |
| }; |
| (@fn $f:ident [$($p:tt)*] : $($tail:tt)*) => { |
| quickcheck!(@fn $f [$($p)* _] $($tail)*) |
| }; |
| (@fn $f:ident [$($p:tt)*] $t:tt $($tail:tt)*) => { |
| quickcheck!(@fn $f [$($p)*] $($tail)*) |
| }; |
| } |
| |
| quickcheck! { |
| |
| fn size_product(a: Iter<u16>, b: Iter<u16>) -> bool { |
| correct_size_hint(a.cartesian_product(b)) |
| } |
| fn size_product3(a: Iter<u16>, b: Iter<u16>, c: Iter<u16>) -> bool { |
| correct_size_hint(iproduct!(a, b, c)) |
| } |
| |
| fn correct_cartesian_product3(a: Iter<u16>, b: Iter<u16>, c: Iter<u16>, |
| take_manual: usize) -> () |
| { |
| // test correctness of iproduct through regular iteration (take) |
| // and through fold. |
| let ac = a.clone(); |
| let br = &b.clone(); |
| let cr = &c.clone(); |
| let answer: Vec<_> = ac.flat_map(move |ea| br.clone().flat_map(move |eb| cr.clone().map(move |ec| (ea, eb, ec)))).collect(); |
| let mut product_iter = iproduct!(a, b, c); |
| let mut actual = Vec::new(); |
| |
| actual.extend((&mut product_iter).take(take_manual)); |
| if actual.len() == take_manual { |
| product_iter.fold((), |(), elt| actual.push(elt)); |
| } |
| assert_eq!(answer, actual); |
| } |
| |
| fn size_multi_product(a: ShiftRange) -> bool { |
| correct_size_hint(a.multi_cartesian_product()) |
| } |
| fn correct_multi_product3(a: ShiftRange, take_manual: usize) -> () { |
| // Fix no. of iterators at 3 |
| let a = ShiftRange { iter_count: 3, ..a }; |
| |
| // test correctness of MultiProduct through regular iteration (take) |
| // and through fold. |
| let mut iters = a.clone(); |
| let i0 = iters.next().unwrap(); |
| let i1r = &iters.next().unwrap(); |
| let i2r = &iters.next().unwrap(); |
| let answer: Vec<_> = i0.flat_map(move |ei0| i1r.clone().flat_map(move |ei1| i2r.clone().map(move |ei2| vec![ei0, ei1, ei2]))).collect(); |
| let mut multi_product = a.clone().multi_cartesian_product(); |
| let mut actual = Vec::new(); |
| |
| actual.extend((&mut multi_product).take(take_manual)); |
| if actual.len() == take_manual { |
| multi_product.fold((), |(), elt| actual.push(elt)); |
| } |
| assert_eq!(answer, actual); |
| |
| assert_eq!(answer.into_iter().last(), a.multi_cartesian_product().last()); |
| } |
| |
| fn correct_empty_multi_product() -> () { |
| let empty = Vec::<std::vec::IntoIter<i32>>::new().into_iter().multi_cartesian_product(); |
| assert!(correct_size_hint(empty.clone())); |
| itertools::assert_equal(empty, std::iter::once(Vec::new())) |
| } |
| |
| fn size_multipeek(a: Iter<u16, Exact>, s: u8) -> bool { |
| let mut it = multipeek(a); |
| // peek a few times |
| for _ in 0..s { |
| it.peek(); |
| } |
| exact_size(it) |
| } |
| |
| fn size_peek_nth(a: Iter<u16, Exact>, s: u8) -> bool { |
| let mut it = peek_nth(a); |
| // peek a few times |
| for n in 0..s { |
| it.peek_nth(n as usize); |
| } |
| exact_size(it) |
| } |
| |
| fn equal_merge(mut a: Vec<i16>, mut b: Vec<i16>) -> bool { |
| a.sort(); |
| b.sort(); |
| let mut merged = a.clone(); |
| merged.extend(b.iter().cloned()); |
| merged.sort(); |
| itertools::equal(&merged, a.iter().merge(&b)) |
| } |
| fn size_merge(a: Iter<u16>, b: Iter<u16>) -> bool { |
| correct_size_hint(a.merge(b)) |
| } |
| fn size_zip(a: Iter<i16, Exact>, b: Iter<i16, Exact>, c: Iter<i16, Exact>) -> bool { |
| let filt = a.clone().dedup(); |
| correct_size_hint(multizip((filt, b.clone(), c.clone()))) && |
| exact_size(multizip((a, b, c))) |
| } |
| fn size_zip_rc(a: Iter<i16>, b: Iter<i16>) -> bool { |
| let rc = rciter(a); |
| correct_size_hint(multizip((&rc, &rc, b))) |
| } |
| |
| fn size_zip_macro(a: Iter<i16, Exact>, b: Iter<i16, Exact>, c: Iter<i16, Exact>) -> bool { |
| let filt = a.clone().dedup(); |
| correct_size_hint(izip!(filt, b.clone(), c.clone())) && |
| exact_size(izip!(a, b, c)) |
| } |
| fn equal_kmerge(mut a: Vec<i16>, mut b: Vec<i16>, mut c: Vec<i16>) -> bool { |
| use itertools::free::kmerge; |
| a.sort(); |
| b.sort(); |
| c.sort(); |
| let mut merged = a.clone(); |
| merged.extend(b.iter().cloned()); |
| merged.extend(c.iter().cloned()); |
| merged.sort(); |
| itertools::equal(merged.into_iter(), kmerge(vec![a, b, c])) |
| } |
| |
| // Any number of input iterators |
| fn equal_kmerge_2(mut inputs: Vec<Vec<i16>>) -> bool { |
| use itertools::free::kmerge; |
| // sort the inputs |
| for input in &mut inputs { |
| input.sort(); |
| } |
| let mut merged = inputs.concat(); |
| merged.sort(); |
| itertools::equal(merged.into_iter(), kmerge(inputs)) |
| } |
| |
| // Any number of input iterators |
| fn equal_kmerge_by_ge(mut inputs: Vec<Vec<i16>>) -> bool { |
| // sort the inputs |
| for input in &mut inputs { |
| input.sort(); |
| input.reverse(); |
| } |
| let mut merged = inputs.concat(); |
| merged.sort(); |
| merged.reverse(); |
| itertools::equal(merged.into_iter(), |
| inputs.into_iter().kmerge_by(|x, y| x >= y)) |
| } |
| |
| // Any number of input iterators |
| fn equal_kmerge_by_lt(mut inputs: Vec<Vec<i16>>) -> bool { |
| // sort the inputs |
| for input in &mut inputs { |
| input.sort(); |
| } |
| let mut merged = inputs.concat(); |
| merged.sort(); |
| itertools::equal(merged.into_iter(), |
| inputs.into_iter().kmerge_by(|x, y| x < y)) |
| } |
| |
| // Any number of input iterators |
| fn equal_kmerge_by_le(mut inputs: Vec<Vec<i16>>) -> bool { |
| // sort the inputs |
| for input in &mut inputs { |
| input.sort(); |
| } |
| let mut merged = inputs.concat(); |
| merged.sort(); |
| itertools::equal(merged.into_iter(), |
| inputs.into_iter().kmerge_by(|x, y| x <= y)) |
| } |
| fn size_kmerge(a: Iter<i16>, b: Iter<i16>, c: Iter<i16>) -> bool { |
| use itertools::free::kmerge; |
| correct_size_hint(kmerge(vec![a, b, c])) |
| } |
| fn equal_zip_eq(a: Vec<i32>, b: Vec<i32>) -> bool { |
| let len = std::cmp::min(a.len(), b.len()); |
| let a = &a[..len]; |
| let b = &b[..len]; |
| itertools::equal(zip_eq(a, b), zip(a, b)) |
| } |
| |
| #[should_panic] |
| fn zip_eq_panics(a: Vec<u8>, b: Vec<u8>) -> TestResult { |
| if a.len() == b.len() { return TestResult::discard(); } |
| zip_eq(a.iter(), b.iter()).for_each(|_| {}); |
| TestResult::passed() // won't come here |
| } |
| |
| fn equal_positions(a: Vec<i32>) -> bool { |
| let with_pos = a.iter().positions(|v| v % 2 == 0); |
| let without = a.iter().enumerate().filter(|(_, v)| *v % 2 == 0).map(|(i, _)| i); |
| itertools::equal(with_pos.clone(), without.clone()) |
| && itertools::equal(with_pos.rev(), without.rev()) |
| } |
| fn size_zip_longest(a: Iter<i16, Exact>, b: Iter<i16, Exact>) -> bool { |
| let filt = a.clone().dedup(); |
| let filt2 = b.clone().dedup(); |
| correct_size_hint(filt.zip_longest(b.clone())) && |
| correct_size_hint(a.clone().zip_longest(filt2)) && |
| exact_size(a.zip_longest(b)) |
| } |
| fn size_2_zip_longest(a: Iter<i16>, b: Iter<i16>) -> bool { |
| let it = a.clone().zip_longest(b.clone()); |
| let jt = a.clone().zip_longest(b.clone()); |
| itertools::equal(a, |
| it.filter_map(|elt| match elt { |
| EitherOrBoth::Both(x, _) => Some(x), |
| EitherOrBoth::Left(x) => Some(x), |
| _ => None, |
| } |
| )) |
| && |
| itertools::equal(b, |
| jt.filter_map(|elt| match elt { |
| EitherOrBoth::Both(_, y) => Some(y), |
| EitherOrBoth::Right(y) => Some(y), |
| _ => None, |
| } |
| )) |
| } |
| fn size_interleave(a: Iter<i16>, b: Iter<i16>) -> bool { |
| correct_size_hint(a.interleave(b)) |
| } |
| fn exact_interleave(a: Iter<i16, Exact>, b: Iter<i16, Exact>) -> bool { |
| exact_size_for_this(a.interleave(b)) |
| } |
| fn size_interleave_shortest(a: Iter<i16>, b: Iter<i16>) -> bool { |
| correct_size_hint(a.interleave_shortest(b)) |
| } |
| fn exact_interleave_shortest(a: Vec<()>, b: Vec<()>) -> bool { |
| exact_size_for_this(a.iter().interleave_shortest(&b)) |
| } |
| fn size_intersperse(a: Iter<i16>, x: i16) -> bool { |
| correct_size_hint(a.intersperse(x)) |
| } |
| fn equal_intersperse(a: Vec<i32>, x: i32) -> bool { |
| let mut inter = false; |
| let mut i = 0; |
| for elt in a.iter().cloned().intersperse(x) { |
| if inter { |
| if elt != x { return false } |
| } else { |
| if elt != a[i] { return false } |
| i += 1; |
| } |
| inter = !inter; |
| } |
| true |
| } |
| |
| fn equal_combinations_2(a: Vec<u8>) -> bool { |
| let mut v = Vec::new(); |
| for (i, x) in enumerate(&a) { |
| for y in &a[i + 1..] { |
| v.push((x, y)); |
| } |
| } |
| itertools::equal(a.iter().tuple_combinations::<(_, _)>(), v) |
| } |
| |
| fn collect_tuple_matches_size(a: Iter<i16>) -> bool { |
| let size = a.clone().count(); |
| a.collect_tuple::<(_, _, _)>().is_some() == (size == 3) |
| } |
| |
| fn correct_permutations(vals: HashSet<i32>, k: usize) -> () { |
| // Test permutations only on iterators of distinct integers, to prevent |
| // false positives. |
| |
| const MAX_N: usize = 5; |
| |
| let n = min(vals.len(), MAX_N); |
| let vals: HashSet<i32> = vals.into_iter().take(n).collect(); |
| |
| let perms = vals.iter().permutations(k); |
| |
| let mut actual = HashSet::new(); |
| |
| for perm in perms { |
| assert_eq!(perm.len(), k); |
| |
| let all_items_valid = perm.iter().all(|p| vals.contains(p)); |
| assert!(all_items_valid, "perm contains value not from input: {:?}", perm); |
| |
| // Check that all perm items are distinct |
| let distinct_len = { |
| let perm_set: HashSet<_> = perm.iter().collect(); |
| perm_set.len() |
| }; |
| assert_eq!(perm.len(), distinct_len); |
| |
| // Check that the perm is new |
| assert!(actual.insert(perm.clone()), "perm already encountered: {:?}", perm); |
| } |
| } |
| |
| fn permutations_lexic_order(a: usize, b: usize) -> () { |
| let a = a % 6; |
| let b = b % 6; |
| |
| let n = max(a, b); |
| let k = min (a, b); |
| |
| let expected_first: Vec<usize> = (0..k).collect(); |
| let expected_last: Vec<usize> = ((n - k)..n).rev().collect(); |
| |
| let mut perms = (0..n).permutations(k); |
| |
| let mut curr_perm = match perms.next() { |
| Some(p) => p, |
| None => { return; } |
| }; |
| |
| assert_eq!(expected_first, curr_perm); |
| |
| for next_perm in perms { |
| assert!( |
| next_perm > curr_perm, |
| "next perm isn't greater-than current; next_perm={:?} curr_perm={:?} n={}", |
| next_perm, curr_perm, n |
| ); |
| |
| curr_perm = next_perm; |
| } |
| |
| assert_eq!(expected_last, curr_perm); |
| |
| } |
| |
| fn permutations_count(n: usize, k: usize) -> bool { |
| let n = n % 6; |
| |
| correct_count(|| (0..n).permutations(k)) |
| } |
| |
| fn permutations_size(a: Iter<i32>, k: usize) -> bool { |
| correct_size_hint(a.take(5).permutations(k)) |
| } |
| |
| fn permutations_k0_yields_once(n: usize) -> () { |
| let k = 0; |
| let expected: Vec<Vec<usize>> = vec![vec![]]; |
| let actual = (0..n).permutations(k).collect_vec(); |
| |
| assert_eq!(expected, actual); |
| } |
| } |
| |
| quickcheck! { |
| fn correct_peek_nth(mut a: Vec<u16>) -> () { |
| let mut it = peek_nth(a.clone()); |
| for start_pos in 0..a.len() + 2 { |
| for real_idx in start_pos..a.len() + 2 { |
| let peek_idx = real_idx - start_pos; |
| assert_eq!(it.peek_nth(peek_idx), a.get(real_idx)); |
| assert_eq!(it.peek_nth_mut(peek_idx), a.get_mut(real_idx)); |
| } |
| assert_eq!(it.next(), a.get(start_pos).copied()); |
| } |
| } |
| |
| fn peek_nth_mut_replace(a: Vec<u16>, b: Vec<u16>) -> () { |
| let mut it = peek_nth(a.iter()); |
| for (i, m) in b.iter().enumerate().take(a.len().min(b.len())) { |
| *it.peek_nth_mut(i).unwrap() = m; |
| } |
| for (i, m) in a.iter().enumerate() { |
| assert_eq!(it.next().unwrap(), b.get(i).unwrap_or(m)); |
| } |
| assert_eq!(it.next(), None); |
| assert_eq!(it.next(), None); |
| } |
| |
| fn peek_nth_next_if(a: Vec<u8>) -> () { |
| let mut it = peek_nth(a.clone()); |
| for (idx, mut value) in a.iter().copied().enumerate() { |
| let should_be_none = it.next_if(|x| x != &value); |
| assert_eq!(should_be_none, None); |
| if value % 5 == 0 { |
| // Sometimes, peek up to 3 further. |
| let n = value as usize % 3; |
| let nth = it.peek_nth(n); |
| assert_eq!(nth, a.get(idx + n)); |
| } else if value % 5 == 1 { |
| // Sometimes, peek next element mutably. |
| if let Some(v) = it.peek_mut() { |
| *v = v.wrapping_sub(1); |
| let should_be_none = it.next_if_eq(&value); |
| assert_eq!(should_be_none, None); |
| value = value.wrapping_sub(1); |
| } |
| } |
| let eq = it.next_if_eq(&value); |
| assert_eq!(eq, Some(value)); |
| } |
| } |
| } |
| |
| quickcheck! { |
| fn dedup_via_coalesce(a: Vec<i32>) -> bool { |
| let mut b = a.clone(); |
| b.dedup(); |
| itertools::equal( |
| &b, |
| a |
| .iter() |
| .coalesce(|x, y| { |
| if x==y { |
| Ok(x) |
| } else { |
| Err((x, y)) |
| } |
| }) |
| .fold(vec![], |mut v, n| { |
| v.push(n); |
| v |
| }) |
| ) |
| } |
| } |
| |
| quickcheck! { |
| fn equal_dedup(a: Vec<i32>) -> bool { |
| let mut b = a.clone(); |
| b.dedup(); |
| itertools::equal(&b, a.iter().dedup()) |
| } |
| } |
| |
| quickcheck! { |
| fn equal_dedup_by(a: Vec<(i32, i32)>) -> bool { |
| let mut b = a.clone(); |
| b.dedup_by(|x, y| x.0==y.0); |
| itertools::equal(&b, a.iter().dedup_by(|x, y| x.0==y.0)) |
| } |
| } |
| |
| quickcheck! { |
| fn size_dedup(a: Vec<i32>) -> bool { |
| correct_size_hint(a.iter().dedup()) |
| } |
| } |
| |
| quickcheck! { |
| fn size_dedup_by(a: Vec<(i32, i32)>) -> bool { |
| correct_size_hint(a.iter().dedup_by(|x, y| x.0==y.0)) |
| } |
| } |
| |
| quickcheck! { |
| fn exact_repeatn((n, x): (usize, i32)) -> bool { |
| let it = itertools::repeat_n(x, n); |
| exact_size(it) |
| } |
| } |
| |
| quickcheck! { |
| fn size_put_back(a: Vec<u8>, x: Option<u8>) -> bool { |
| let mut it = put_back(a.into_iter()); |
| if let Some(t) = x { |
| it.put_back(t); |
| } |
| correct_size_hint(it) |
| } |
| } |
| |
| quickcheck! { |
| fn size_put_backn(a: Vec<u8>, b: Vec<u8>) -> bool { |
| let mut it = put_back_n(a.into_iter()); |
| for elt in b { |
| it.put_back(elt) |
| } |
| correct_size_hint(it) |
| } |
| } |
| |
| quickcheck! { |
| fn merge_join_by_ordering_vs_bool(a: Vec<u8>, b: Vec<u8>) -> bool { |
| use either::Either; |
| use itertools::free::merge_join_by; |
| let mut has_equal = false; |
| let it_ord = merge_join_by(a.clone(), b.clone(), Ord::cmp).flat_map(|v| match v { |
| EitherOrBoth::Both(l, r) => { |
| has_equal = true; |
| vec![Either::Left(l), Either::Right(r)] |
| } |
| EitherOrBoth::Left(l) => vec![Either::Left(l)], |
| EitherOrBoth::Right(r) => vec![Either::Right(r)], |
| }); |
| let it_bool = merge_join_by(a, b, PartialOrd::le); |
| itertools::equal(it_ord, it_bool) || has_equal |
| } |
| fn merge_join_by_bool_unwrapped_is_merge_by(a: Vec<u8>, b: Vec<u8>) -> bool { |
| use either::Either; |
| use itertools::free::merge_join_by; |
| let it = a.clone().into_iter().merge_by(b.clone(), PartialOrd::ge); |
| let it_join = merge_join_by(a, b, PartialOrd::ge).map(Either::into_inner); |
| itertools::equal(it, it_join) |
| } |
| } |
| |
| quickcheck! { |
| fn size_tee(a: Vec<u8>) -> bool { |
| let (mut t1, mut t2) = a.iter().tee(); |
| t1.next(); |
| t1.next(); |
| t2.next(); |
| exact_size(t1) && exact_size(t2) |
| } |
| } |
| |
| quickcheck! { |
| fn size_tee_2(a: Vec<u8>) -> bool { |
| let (mut t1, mut t2) = a.iter().dedup().tee(); |
| t1.next(); |
| t1.next(); |
| t2.next(); |
| correct_size_hint(t1) && correct_size_hint(t2) |
| } |
| } |
| |
| quickcheck! { |
| fn size_take_while_ref(a: Vec<u8>, stop: u8) -> bool { |
| correct_size_hint(a.iter().take_while_ref(|x| **x != stop)) |
| } |
| } |
| |
| quickcheck! { |
| fn equal_partition(a: Vec<i32>) -> bool { |
| let mut a = a; |
| let mut ap = a.clone(); |
| let split_index = itertools::partition(&mut ap, |x| *x >= 0); |
| let parted = (0..split_index).all(|i| ap[i] >= 0) && |
| (split_index..a.len()).all(|i| ap[i] < 0); |
| |
| a.sort(); |
| ap.sort(); |
| parted && (a == ap) |
| } |
| } |
| |
| quickcheck! { |
| fn size_combinations(a: Iter<i16>) -> bool { |
| let it = a.clone().tuple_combinations::<(_, _)>(); |
| correct_size_hint(it.clone()) && it.count() == binomial(a.count(), 2) |
| } |
| |
| fn exact_size_combinations_1(a: Vec<u8>) -> bool { |
| let it = a.iter().tuple_combinations::<(_,)>(); |
| exact_size_for_this(it.clone()) && it.count() == binomial(a.len(), 1) |
| } |
| fn exact_size_combinations_2(a: Vec<u8>) -> bool { |
| let it = a.iter().tuple_combinations::<(_, _)>(); |
| exact_size_for_this(it.clone()) && it.count() == binomial(a.len(), 2) |
| } |
| fn exact_size_combinations_3(mut a: Vec<u8>) -> bool { |
| a.truncate(15); |
| let it = a.iter().tuple_combinations::<(_, _, _)>(); |
| exact_size_for_this(it.clone()) && it.count() == binomial(a.len(), 3) |
| } |
| } |
| |
| fn binomial(n: usize, k: usize) -> usize { |
| if k > n { |
| 0 |
| } else { |
| (n - k + 1..=n).product::<usize>() / (1..=k).product::<usize>() |
| } |
| } |
| |
| quickcheck! { |
| fn equal_combinations(it: Iter<i16>) -> bool { |
| let values = it.clone().collect_vec(); |
| let mut cmb = it.tuple_combinations(); |
| for i in 0..values.len() { |
| for j in i+1..values.len() { |
| let pair = (values[i], values[j]); |
| if pair != cmb.next().unwrap() { |
| return false; |
| } |
| } |
| } |
| cmb.next().is_none() |
| } |
| } |
| |
| quickcheck! { |
| fn size_pad_tail(it: Iter<i8>, pad: u8) -> bool { |
| correct_size_hint(it.clone().pad_using(pad as usize, |_| 0)) && |
| correct_size_hint(it.dropping(1).rev().pad_using(pad as usize, |_| 0)) |
| } |
| } |
| |
| quickcheck! { |
| fn size_pad_tail2(it: Iter<i8, Exact>, pad: u8) -> bool { |
| exact_size(it.pad_using(pad as usize, |_| 0)) |
| } |
| } |
| |
| quickcheck! { |
| fn size_powerset(it: Iter<u8, Exact>) -> bool { |
| // Powerset cardinality gets large very quickly, limit input to keep test fast. |
| correct_size_hint(it.take(12).powerset()) |
| } |
| } |
| |
| quickcheck! { |
| fn size_duplicates(it: Iter<i8>) -> bool { |
| correct_size_hint(it.duplicates()) |
| } |
| } |
| |
| quickcheck! { |
| fn size_unique(it: Iter<i8>) -> bool { |
| correct_size_hint(it.unique()) |
| } |
| |
| fn count_unique(it: Vec<i8>, take_first: u8) -> () { |
| let answer = { |
| let mut v = it.clone(); |
| v.sort(); v.dedup(); |
| v.len() |
| }; |
| let mut iter = cloned(&it).unique(); |
| let first_count = (&mut iter).take(take_first as usize).count(); |
| let rest_count = iter.count(); |
| assert_eq!(answer, first_count + rest_count); |
| } |
| } |
| |
| quickcheck! { |
| fn fuzz_chunk_by_lazy_1(it: Iter<u8>) -> bool { |
| let jt = it.clone(); |
| let chunks = it.chunk_by(|k| *k); |
| itertools::equal(jt, chunks.into_iter().flat_map(|(_, x)| x)) |
| } |
| } |
| |
| quickcheck! { |
| fn fuzz_chunk_by_lazy_2(data: Vec<u8>) -> bool { |
| let chunks = data.iter().chunk_by(|k| *k / 10); |
| let res = itertools::equal(data.iter(), chunks.into_iter().flat_map(|(_, x)| x)); |
| res |
| } |
| } |
| |
| quickcheck! { |
| fn fuzz_chunk_by_lazy_3(data: Vec<u8>) -> bool { |
| let grouper = data.iter().chunk_by(|k| *k / 10); |
| let chunks = grouper.into_iter().collect_vec(); |
| let res = itertools::equal(data.iter(), chunks.into_iter().flat_map(|(_, x)| x)); |
| res |
| } |
| } |
| |
| quickcheck! { |
| fn fuzz_chunk_by_lazy_duo(data: Vec<u8>, order: Vec<(bool, bool)>) -> bool { |
| let grouper = data.iter().chunk_by(|k| *k / 3); |
| let mut chunks1 = grouper.into_iter(); |
| let mut chunks2 = grouper.into_iter(); |
| let mut elts = Vec::<&u8>::new(); |
| let mut old_chunks = Vec::new(); |
| |
| let tup1 = |(_, b)| b; |
| for &(ord, consume_now) in &order { |
| let iter = &mut [&mut chunks1, &mut chunks2][ord as usize]; |
| match iter.next() { |
| Some((_, gr)) => if consume_now { |
| for og in old_chunks.drain(..) { |
| elts.extend(og); |
| } |
| elts.extend(gr); |
| } else { |
| old_chunks.push(gr); |
| }, |
| None => break, |
| } |
| } |
| for og in old_chunks.drain(..) { |
| elts.extend(og); |
| } |
| for gr in chunks1.map(&tup1) { elts.extend(gr); } |
| for gr in chunks2.map(&tup1) { elts.extend(gr); } |
| itertools::assert_equal(&data, elts); |
| true |
| } |
| } |
| |
| quickcheck! { |
| fn chunk_clone_equal(a: Vec<u8>, size: u8) -> () { |
| let mut size = size; |
| if size == 0 { |
| size += 1; |
| } |
| let it = a.chunks(size as usize); |
| itertools::assert_equal(it.clone(), it); |
| } |
| } |
| |
| quickcheck! { |
| fn equal_chunks_lazy(a: Vec<u8>, size: u8) -> bool { |
| let mut size = size; |
| if size == 0 { |
| size += 1; |
| } |
| let chunks = a.iter().chunks(size as usize); |
| let it = a.chunks(size as usize); |
| for (a, b) in chunks.into_iter().zip(it) { |
| if !itertools::equal(a, b) { |
| return false; |
| } |
| } |
| true |
| } |
| } |
| |
| // tuple iterators |
| quickcheck! { |
| fn equal_circular_tuple_windows_1(a: Vec<u8>) -> bool { |
| let x = a.iter().map(|e| (e,) ); |
| let y = a.iter().circular_tuple_windows::<(_,)>(); |
| itertools::assert_equal(x,y); |
| true |
| } |
| |
| fn equal_circular_tuple_windows_2(a: Vec<u8>) -> bool { |
| let x = (0..a.len()).map(|start_idx| ( |
| &a[start_idx], |
| &a[(start_idx + 1) % a.len()], |
| )); |
| let y = a.iter().circular_tuple_windows::<(_, _)>(); |
| itertools::assert_equal(x,y); |
| true |
| } |
| |
| fn equal_circular_tuple_windows_3(a: Vec<u8>) -> bool { |
| let x = (0..a.len()).map(|start_idx| ( |
| &a[start_idx], |
| &a[(start_idx + 1) % a.len()], |
| &a[(start_idx + 2) % a.len()], |
| )); |
| let y = a.iter().circular_tuple_windows::<(_, _, _)>(); |
| itertools::assert_equal(x,y); |
| true |
| } |
| |
| fn equal_circular_tuple_windows_4(a: Vec<u8>) -> bool { |
| let x = (0..a.len()).map(|start_idx| ( |
| &a[start_idx], |
| &a[(start_idx + 1) % a.len()], |
| &a[(start_idx + 2) % a.len()], |
| &a[(start_idx + 3) % a.len()], |
| )); |
| let y = a.iter().circular_tuple_windows::<(_, _, _, _)>(); |
| itertools::assert_equal(x,y); |
| true |
| } |
| |
| fn equal_cloned_circular_tuple_windows(a: Vec<u8>) -> bool { |
| let x = a.iter().circular_tuple_windows::<(_, _, _, _)>(); |
| let y = x.clone(); |
| itertools::assert_equal(x,y); |
| true |
| } |
| |
| fn equal_cloned_circular_tuple_windows_noninitial(a: Vec<u8>) -> bool { |
| let mut x = a.iter().circular_tuple_windows::<(_, _, _, _)>(); |
| let _ = x.next(); |
| let y = x.clone(); |
| itertools::assert_equal(x,y); |
| true |
| } |
| |
| fn equal_cloned_circular_tuple_windows_complete(a: Vec<u8>) -> bool { |
| let mut x = a.iter().circular_tuple_windows::<(_, _, _, _)>(); |
| for _ in x.by_ref() {} |
| let y = x.clone(); |
| itertools::assert_equal(x,y); |
| true |
| } |
| |
| fn circular_tuple_windows_exact_size(a: Vec<u8>) -> bool { |
| exact_size(a.iter().circular_tuple_windows::<(_, _, _, _)>()) |
| } |
| |
| fn equal_tuple_windows_1(a: Vec<u8>) -> bool { |
| let x = a.windows(1).map(|s| (&s[0], )); |
| let y = a.iter().tuple_windows::<(_,)>(); |
| itertools::equal(x, y) |
| } |
| |
| fn equal_tuple_windows_2(a: Vec<u8>) -> bool { |
| let x = a.windows(2).map(|s| (&s[0], &s[1])); |
| let y = a.iter().tuple_windows::<(_, _)>(); |
| itertools::equal(x, y) |
| } |
| |
| fn equal_tuple_windows_3(a: Vec<u8>) -> bool { |
| let x = a.windows(3).map(|s| (&s[0], &s[1], &s[2])); |
| let y = a.iter().tuple_windows::<(_, _, _)>(); |
| itertools::equal(x, y) |
| } |
| |
| fn equal_tuple_windows_4(a: Vec<u8>) -> bool { |
| let x = a.windows(4).map(|s| (&s[0], &s[1], &s[2], &s[3])); |
| let y = a.iter().tuple_windows::<(_, _, _, _)>(); |
| itertools::equal(x, y) |
| } |
| |
| fn tuple_windows_exact_size_1(a: Vec<u8>) -> bool { |
| exact_size(a.iter().tuple_windows::<(_,)>()) |
| } |
| |
| fn tuple_windows_exact_size_4(a: Vec<u8>) -> bool { |
| exact_size(a.iter().tuple_windows::<(_, _, _, _)>()) |
| } |
| |
| fn equal_tuples_1(a: Vec<u8>) -> bool { |
| let x = a.chunks(1).map(|s| (&s[0], )); |
| let y = a.iter().tuples::<(_,)>(); |
| itertools::equal(x, y) |
| } |
| |
| fn equal_tuples_2(a: Vec<u8>) -> bool { |
| let x = a.chunks(2).filter(|s| s.len() == 2).map(|s| (&s[0], &s[1])); |
| let y = a.iter().tuples::<(_, _)>(); |
| itertools::equal(x, y) |
| } |
| |
| fn equal_tuples_3(a: Vec<u8>) -> bool { |
| let x = a.chunks(3).filter(|s| s.len() == 3).map(|s| (&s[0], &s[1], &s[2])); |
| let y = a.iter().tuples::<(_, _, _)>(); |
| itertools::equal(x, y) |
| } |
| |
| fn equal_tuples_4(a: Vec<u8>) -> bool { |
| let x = a.chunks(4).filter(|s| s.len() == 4).map(|s| (&s[0], &s[1], &s[2], &s[3])); |
| let y = a.iter().tuples::<(_, _, _, _)>(); |
| itertools::equal(x, y) |
| } |
| |
| fn exact_tuple_buffer(a: Vec<u8>) -> bool { |
| let mut iter = a.iter().tuples::<(_, _, _, _)>(); |
| (&mut iter).last(); |
| let buffer = iter.into_buffer(); |
| assert_eq!(buffer.len(), a.len() % 4); |
| exact_size(buffer) |
| } |
| |
| fn tuples_size_hint_inexact(a: Iter<u8>) -> bool { |
| correct_size_hint(a.clone().tuples::<(_,)>()) |
| && correct_size_hint(a.clone().tuples::<(_, _)>()) |
| && correct_size_hint(a.tuples::<(_, _, _, _)>()) |
| } |
| |
| fn tuples_size_hint_exact(a: Iter<u8, Exact>) -> bool { |
| exact_size(a.clone().tuples::<(_,)>()) |
| && exact_size(a.clone().tuples::<(_, _)>()) |
| && exact_size(a.tuples::<(_, _, _, _)>()) |
| } |
| } |
| |
| // with_position |
| quickcheck! { |
| fn with_position_exact_size_1(a: Vec<u8>) -> bool { |
| exact_size_for_this(a.iter().with_position()) |
| } |
| fn with_position_exact_size_2(a: Iter<u8, Exact>) -> bool { |
| exact_size_for_this(a.with_position()) |
| } |
| } |
| |
| quickcheck! { |
| fn correct_group_map_modulo_key(a: Vec<u8>, modulo: u8) -> () { |
| let modulo = if modulo == 0 { 1 } else { modulo }; // Avoid `% 0` |
| let count = a.len(); |
| let lookup = a.into_iter().map(|i| (i % modulo, i)).into_group_map(); |
| |
| assert_eq!(lookup.values().flat_map(|vals| vals.iter()).count(), count); |
| |
| for (&key, vals) in lookup.iter() { |
| assert!(vals.iter().all(|&val| val % modulo == key)); |
| } |
| } |
| } |
| |
| /// A peculiar type: Equality compares both tuple items, but ordering only the |
| /// first item. This is so we can check the stability property easily. |
| #[derive(Clone, Debug, PartialEq, Eq)] |
| struct Val(u32, u32); |
| |
| impl PartialOrd<Self> for Val { |
| fn partial_cmp(&self, other: &Self) -> Option<Ordering> { |
| Some(self.cmp(other)) |
| } |
| } |
| |
| impl Ord for Val { |
| fn cmp(&self, other: &Self) -> Ordering { |
| self.0.cmp(&other.0) |
| } |
| } |
| |
| impl qc::Arbitrary for Val { |
| fn arbitrary<G: qc::Gen>(g: &mut G) -> Self { |
| let (x, y) = <(u32, u32)>::arbitrary(g); |
| Self(x, y) |
| } |
| fn shrink(&self) -> Box<dyn Iterator<Item = Self>> { |
| Box::new((self.0, self.1).shrink().map(|(x, y)| Self(x, y))) |
| } |
| } |
| |
| quickcheck! { |
| fn minmax(a: Vec<Val>) -> bool { |
| use itertools::MinMaxResult; |
| |
| |
| let minmax = a.iter().minmax(); |
| let expected = match a.len() { |
| 0 => MinMaxResult::NoElements, |
| 1 => MinMaxResult::OneElement(&a[0]), |
| _ => MinMaxResult::MinMax(a.iter().min().unwrap(), |
| a.iter().max().unwrap()), |
| }; |
| minmax == expected |
| } |
| } |
| |
| quickcheck! { |
| fn minmax_f64(a: Vec<f64>) -> TestResult { |
| use itertools::MinMaxResult; |
| |
| if a.iter().any(|x| x.is_nan()) { |
| return TestResult::discard(); |
| } |
| |
| let min = cloned(&a).fold1(f64::min); |
| let max = cloned(&a).fold1(f64::max); |
| |
| let minmax = cloned(&a).minmax(); |
| let expected = match a.len() { |
| 0 => MinMaxResult::NoElements, |
| 1 => MinMaxResult::OneElement(min.unwrap()), |
| _ => MinMaxResult::MinMax(min.unwrap(), max.unwrap()), |
| }; |
| TestResult::from_bool(minmax == expected) |
| } |
| } |
| |
| quickcheck! { |
| fn tree_reduce_f64(mut a: Vec<f64>) -> TestResult { |
| fn collapse_adjacent<F>(x: Vec<f64>, mut f: F) -> Vec<f64> |
| where F: FnMut(f64, f64) -> f64 |
| { |
| let mut out = Vec::new(); |
| for i in (0..x.len()).step_by(2) { |
| if i == x.len()-1 { |
| out.push(x[i]) |
| } else { |
| out.push(f(x[i], x[i+1])); |
| } |
| } |
| out |
| } |
| |
| if a.iter().any(|x| x.is_nan()) { |
| return TestResult::discard(); |
| } |
| |
| let actual = a.iter().cloned().tree_reduce(f64::atan2); |
| |
| while a.len() > 1 { |
| a = collapse_adjacent(a, f64::atan2); |
| } |
| let expected = a.pop(); |
| |
| TestResult::from_bool(actual == expected) |
| } |
| } |
| |
| quickcheck! { |
| fn exactly_one_i32(a: Vec<i32>) -> TestResult { |
| let ret = a.iter().cloned().exactly_one(); |
| match a.len() { |
| 1 => TestResult::from_bool(ret.unwrap() == a[0]), |
| _ => TestResult::from_bool(ret.unwrap_err().eq(a.iter().cloned())), |
| } |
| } |
| } |
| |
| quickcheck! { |
| fn at_most_one_i32(a: Vec<i32>) -> TestResult { |
| let ret = a.iter().cloned().at_most_one(); |
| match a.len() { |
| 0 => TestResult::from_bool(ret.unwrap().is_none()), |
| 1 => TestResult::from_bool(ret.unwrap() == Some(a[0])), |
| _ => TestResult::from_bool(ret.unwrap_err().eq(a.iter().cloned())), |
| } |
| } |
| } |
| |
| quickcheck! { |
| fn consistent_grouping_map_with_by(a: Vec<u8>, modulo: u8) -> () { |
| let modulo = if modulo == 0 { 1 } else { modulo }; // Avoid `% 0` |
| |
| let lookup_grouping_map = a.iter().copied().map(|i| (i % modulo, i)).into_grouping_map().collect::<Vec<_>>(); |
| let lookup_grouping_map_by = a.iter().copied().into_grouping_map_by(|i| i % modulo).collect::<Vec<_>>(); |
| |
| assert_eq!(lookup_grouping_map, lookup_grouping_map_by); |
| } |
| |
| fn correct_grouping_map_by_aggregate_modulo_key(a: Vec<u8>, modulo: u8) -> () { |
| let modulo = if modulo < 2 { 2 } else { modulo } as u64; // Avoid `% 0` |
| let lookup = a.iter() |
| .map(|&b| b as u64) // Avoid overflows |
| .into_grouping_map_by(|i| i % modulo) |
| .aggregate(|acc, &key, val| { |
| assert!(val % modulo == key); |
| if val % (modulo - 1) == 0 { |
| None |
| } else { |
| Some(acc.unwrap_or(0) + val) |
| } |
| }); |
| |
| let group_map_lookup = a.iter() |
| .map(|&b| b as u64) |
| .map(|i| (i % modulo, i)) |
| .into_group_map() |
| .into_iter() |
| .filter_map(|(key, vals)| { |
| vals.into_iter().fold(None, |acc, val| { |
| if val % (modulo - 1) == 0 { |
| None |
| } else { |
| Some(acc.unwrap_or(0) + val) |
| } |
| }).map(|new_val| (key, new_val)) |
| }) |
| .collect::<HashMap<_,_>>(); |
| assert_eq!(lookup, group_map_lookup); |
| |
| for m in 0..modulo { |
| assert_eq!( |
| lookup.get(&m).copied(), |
| a.iter() |
| .map(|&b| b as u64) |
| .filter(|&val| val % modulo == m) |
| .fold(None, |acc, val| { |
| if val % (modulo - 1) == 0 { |
| None |
| } else { |
| Some(acc.unwrap_or(0) + val) |
| } |
| }) |
| ); |
| } |
| } |
| |
| fn correct_grouping_map_by_fold_with_modulo_key(a: Vec<u8>, modulo: u8) -> () { |
| #[derive(Debug, Default, PartialEq)] |
| struct Accumulator { |
| acc: u64, |
| } |
| |
| let modulo = if modulo == 0 { 1 } else { modulo } as u64; // Avoid `% 0` |
| let lookup = a.iter().map(|&b| b as u64) // Avoid overflows |
| .into_grouping_map_by(|i| i % modulo) |
| .fold_with(|_key, _val| Default::default(), |Accumulator { acc }, &key, val| { |
| assert!(val % modulo == key); |
| let acc = acc + val; |
| Accumulator { acc } |
| }); |
| |
| let group_map_lookup = a.iter() |
| .map(|&b| b as u64) |
| .map(|i| (i % modulo, i)) |
| .into_group_map() |
| .into_iter() |
| .map(|(key, vals)| (key, vals.into_iter().sum())).map(|(key, acc)| (key,Accumulator { acc })) |
| .collect::<HashMap<_,_>>(); |
| assert_eq!(lookup, group_map_lookup); |
| |
| for (&key, &Accumulator { acc: sum }) in lookup.iter() { |
| assert_eq!(sum, a.iter().map(|&b| b as u64).filter(|&val| val % modulo == key).sum::<u64>()); |
| } |
| } |
| |
| fn correct_grouping_map_by_fold_modulo_key(a: Vec<u8>, modulo: u8) -> () { |
| let modulo = if modulo == 0 { 1 } else { modulo } as u64; // Avoid `% 0` |
| let lookup = a.iter().map(|&b| b as u64) // Avoid overflows |
| .into_grouping_map_by(|i| i % modulo) |
| .fold(0u64, |acc, &key, val| { |
| assert!(val % modulo == key); |
| acc + val |
| }); |
| |
| let group_map_lookup = a.iter() |
| .map(|&b| b as u64) |
| .map(|i| (i % modulo, i)) |
| .into_group_map() |
| .into_iter() |
| .map(|(key, vals)| (key, vals.into_iter().sum())) |
| .collect::<HashMap<_,_>>(); |
| assert_eq!(lookup, group_map_lookup); |
| |
| for (&key, &sum) in lookup.iter() { |
| assert_eq!(sum, a.iter().map(|&b| b as u64).filter(|&val| val % modulo == key).sum::<u64>()); |
| } |
| } |
| |
| fn correct_grouping_map_by_reduce_modulo_key(a: Vec<u8>, modulo: u8) -> () { |
| let modulo = if modulo == 0 { 1 } else { modulo } as u64; // Avoid `% 0` |
| let lookup = a.iter().map(|&b| b as u64) // Avoid overflows |
| .into_grouping_map_by(|i| i % modulo) |
| .reduce(|acc, &key, val| { |
| assert!(val % modulo == key); |
| acc + val |
| }); |
| |
| // TODO: Swap `fold1` with stdlib's `reduce` when it's stabilized |
| let group_map_lookup = a.iter() |
| .map(|&b| b as u64) |
| .map(|i| (i % modulo, i)) |
| .into_group_map() |
| .into_iter() |
| .map(|(key, vals)| (key, vals.into_iter().fold1(|acc, val| acc + val).unwrap())) |
| .collect::<HashMap<_,_>>(); |
| assert_eq!(lookup, group_map_lookup); |
| |
| for (&key, &sum) in lookup.iter() { |
| assert_eq!(sum, a.iter().map(|&b| b as u64).filter(|&val| val % modulo == key).sum::<u64>()); |
| } |
| } |
| |
| fn correct_grouping_map_by_collect_modulo_key(a: Vec<u8>, modulo: u8) -> () { |
| let modulo = if modulo == 0 { 1 } else { modulo }; // Avoid `% 0` |
| let lookup_grouping_map = a.iter().copied().into_grouping_map_by(|i| i % modulo).collect::<Vec<_>>(); |
| let lookup_group_map = a.iter().copied().map(|i| (i % modulo, i)).into_group_map(); |
| |
| assert_eq!(lookup_grouping_map, lookup_group_map); |
| } |
| |
| fn correct_grouping_map_by_max_modulo_key(a: Vec<u8>, modulo: u8) -> () { |
| let modulo = if modulo == 0 { 1 } else { modulo }; // Avoid `% 0` |
| let lookup = a.iter().copied().into_grouping_map_by(|i| i % modulo).max(); |
| |
| let group_map_lookup = a.iter().copied() |
| .map(|i| (i % modulo, i)) |
| .into_group_map() |
| .into_iter() |
| .map(|(key, vals)| (key, vals.into_iter().max().unwrap())) |
| .collect::<HashMap<_,_>>(); |
| assert_eq!(lookup, group_map_lookup); |
| |
| for (&key, &max) in lookup.iter() { |
| assert_eq!(Some(max), a.iter().copied().filter(|&val| val % modulo == key).max()); |
| } |
| } |
| |
| fn correct_grouping_map_by_max_by_modulo_key(a: Vec<u8>, modulo: u8) -> () { |
| let modulo = if modulo == 0 { 1 } else { modulo }; // Avoid `% 0` |
| let lookup = a.iter().copied().into_grouping_map_by(|i| i % modulo).max_by(|_, v1, v2| v1.cmp(v2)); |
| |
| let group_map_lookup = a.iter().copied() |
| .map(|i| (i % modulo, i)) |
| .into_group_map() |
| .into_iter() |
| .map(|(key, vals)| (key, vals.into_iter().max_by(|v1, v2| v1.cmp(v2)).unwrap())) |
| .collect::<HashMap<_,_>>(); |
| assert_eq!(lookup, group_map_lookup); |
| |
| for (&key, &max) in lookup.iter() { |
| assert_eq!(Some(max), a.iter().copied().filter(|&val| val % modulo == key).max_by(|v1, v2| v1.cmp(v2))); |
| } |
| } |
| |
| fn correct_grouping_map_by_max_by_key_modulo_key(a: Vec<u8>, modulo: u8) -> () { |
| let modulo = if modulo == 0 { 1 } else { modulo }; // Avoid `% 0` |
| let lookup = a.iter().copied().into_grouping_map_by(|i| i % modulo).max_by_key(|_, &val| val); |
| |
| let group_map_lookup = a.iter().copied() |
| .map(|i| (i % modulo, i)) |
| .into_group_map() |
| .into_iter() |
| .map(|(key, vals)| (key, vals.into_iter().max_by_key(|&val| val).unwrap())) |
| .collect::<HashMap<_,_>>(); |
| assert_eq!(lookup, group_map_lookup); |
| |
| for (&key, &max) in lookup.iter() { |
| assert_eq!(Some(max), a.iter().copied().filter(|&val| val % modulo == key).max_by_key(|&val| val)); |
| } |
| } |
| |
| fn correct_grouping_map_by_min_modulo_key(a: Vec<u8>, modulo: u8) -> () { |
| let modulo = if modulo == 0 { 1 } else { modulo }; // Avoid `% 0` |
| let lookup = a.iter().copied().into_grouping_map_by(|i| i % modulo).min(); |
| |
| let group_map_lookup = a.iter().copied() |
| .map(|i| (i % modulo, i)) |
| .into_group_map() |
| .into_iter() |
| .map(|(key, vals)| (key, vals.into_iter().min().unwrap())) |
| .collect::<HashMap<_,_>>(); |
| assert_eq!(lookup, group_map_lookup); |
| |
| for (&key, &min) in lookup.iter() { |
| assert_eq!(Some(min), a.iter().copied().filter(|&val| val % modulo == key).min()); |
| } |
| } |
| |
| fn correct_grouping_map_by_min_by_modulo_key(a: Vec<u8>, modulo: u8) -> () { |
| let modulo = if modulo == 0 { 1 } else { modulo }; // Avoid `% 0` |
| let lookup = a.iter().copied().into_grouping_map_by(|i| i % modulo).min_by(|_, v1, v2| v1.cmp(v2)); |
| |
| let group_map_lookup = a.iter().copied() |
| .map(|i| (i % modulo, i)) |
| .into_group_map() |
| .into_iter() |
| .map(|(key, vals)| (key, vals.into_iter().min_by(|v1, v2| v1.cmp(v2)).unwrap())) |
| .collect::<HashMap<_,_>>(); |
| assert_eq!(lookup, group_map_lookup); |
| |
| for (&key, &min) in lookup.iter() { |
| assert_eq!(Some(min), a.iter().copied().filter(|&val| val % modulo == key).min_by(|v1, v2| v1.cmp(v2))); |
| } |
| } |
| |
| fn correct_grouping_map_by_min_by_key_modulo_key(a: Vec<u8>, modulo: u8) -> () { |
| let modulo = if modulo == 0 { 1 } else { modulo }; // Avoid `% 0` |
| let lookup = a.iter().copied().into_grouping_map_by(|i| i % modulo).min_by_key(|_, &val| val); |
| |
| let group_map_lookup = a.iter().copied() |
| .map(|i| (i % modulo, i)) |
| .into_group_map() |
| .into_iter() |
| .map(|(key, vals)| (key, vals.into_iter().min_by_key(|&val| val).unwrap())) |
| .collect::<HashMap<_,_>>(); |
| assert_eq!(lookup, group_map_lookup); |
| |
| for (&key, &min) in lookup.iter() { |
| assert_eq!(Some(min), a.iter().copied().filter(|&val| val % modulo == key).min_by_key(|&val| val)); |
| } |
| } |
| |
| fn correct_grouping_map_by_minmax_modulo_key(a: Vec<u8>, modulo: u8) -> () { |
| let modulo = if modulo == 0 { 1 } else { modulo }; // Avoid `% 0` |
| let lookup = a.iter().copied().into_grouping_map_by(|i| i % modulo).minmax(); |
| |
| let group_map_lookup = a.iter().copied() |
| .map(|i| (i % modulo, i)) |
| .into_group_map() |
| .into_iter() |
| .map(|(key, vals)| (key, vals.into_iter().minmax())) |
| .collect::<HashMap<_,_>>(); |
| assert_eq!(lookup, group_map_lookup); |
| |
| for (&key, &minmax) in lookup.iter() { |
| assert_eq!(minmax, a.iter().copied().filter(|&val| val % modulo == key).minmax()); |
| } |
| } |
| |
| fn correct_grouping_map_by_minmax_by_modulo_key(a: Vec<u8>, modulo: u8) -> () { |
| let modulo = if modulo == 0 { 1 } else { modulo }; // Avoid `% 0` |
| let lookup = a.iter().copied().into_grouping_map_by(|i| i % modulo).minmax_by(|_, v1, v2| v1.cmp(v2)); |
| |
| let group_map_lookup = a.iter().copied() |
| .map(|i| (i % modulo, i)) |
| .into_group_map() |
| .into_iter() |
| .map(|(key, vals)| (key, vals.into_iter().minmax_by(|v1, v2| v1.cmp(v2)))) |
| .collect::<HashMap<_,_>>(); |
| assert_eq!(lookup, group_map_lookup); |
| |
| for (&key, &minmax) in lookup.iter() { |
| assert_eq!(minmax, a.iter().copied().filter(|&val| val % modulo == key).minmax_by(|v1, v2| v1.cmp(v2))); |
| } |
| } |
| |
| fn correct_grouping_map_by_minmax_by_key_modulo_key(a: Vec<u8>, modulo: u8) -> () { |
| let modulo = if modulo == 0 { 1 } else { modulo }; // Avoid `% 0` |
| let lookup = a.iter().copied().into_grouping_map_by(|i| i % modulo).minmax_by_key(|_, &val| val); |
| |
| let group_map_lookup = a.iter().copied() |
| .map(|i| (i % modulo, i)) |
| .into_group_map() |
| .into_iter() |
| .map(|(key, vals)| (key, vals.into_iter().minmax_by_key(|&val| val))) |
| .collect::<HashMap<_,_>>(); |
| assert_eq!(lookup, group_map_lookup); |
| |
| for (&key, &minmax) in lookup.iter() { |
| assert_eq!(minmax, a.iter().copied().filter(|&val| val % modulo == key).minmax_by_key(|&val| val)); |
| } |
| } |
| |
| fn correct_grouping_map_by_sum_modulo_key(a: Vec<u8>, modulo: u8) -> () { |
| let modulo = if modulo == 0 { 1 } else { modulo } as u64; // Avoid `% 0` |
| let lookup = a.iter().map(|&b| b as u64) // Avoid overflows |
| .into_grouping_map_by(|i| i % modulo) |
| .sum(); |
| |
| let group_map_lookup = a.iter().map(|&b| b as u64) |
| .map(|i| (i % modulo, i)) |
| .into_group_map() |
| .into_iter() |
| .map(|(key, vals)| (key, vals.into_iter().sum())) |
| .collect::<HashMap<_,_>>(); |
| assert_eq!(lookup, group_map_lookup); |
| |
| for (&key, &sum) in lookup.iter() { |
| assert_eq!(sum, a.iter().map(|&b| b as u64).filter(|&val| val % modulo == key).sum::<u64>()); |
| } |
| } |
| |
| fn correct_grouping_map_by_product_modulo_key(a: Vec<u8>, modulo: u8) -> () { |
| let modulo = Wrapping(if modulo == 0 { 1 } else { modulo } as u64); // Avoid `% 0` |
| let lookup = a.iter().map(|&b| Wrapping(b as u64)) // Avoid overflows |
| .into_grouping_map_by(|i| i % modulo) |
| .product(); |
| |
| let group_map_lookup = a.iter().map(|&b| Wrapping(b as u64)) |
| .map(|i| (i % modulo, i)) |
| .into_group_map() |
| .into_iter() |
| .map(|(key, vals)| (key, vals.into_iter().product::<Wrapping<u64>>())) |
| .collect::<HashMap<_,_>>(); |
| assert_eq!(lookup, group_map_lookup); |
| |
| for (&key, &prod) in lookup.iter() { |
| assert_eq!( |
| prod, |
| a.iter() |
| .map(|&b| Wrapping(b as u64)) |
| .filter(|&val| val % modulo == key) |
| .product::<Wrapping<u64>>() |
| ); |
| } |
| } |
| |
| // This should check that if multiple elements are equally minimum or maximum |
| // then `max`, `min` and `minmax` pick the first minimum and the last maximum. |
| // This is to be consistent with `std::iter::max` and `std::iter::min`. |
| fn correct_grouping_map_by_min_max_minmax_order_modulo_key() -> () { |
| use itertools::MinMaxResult; |
| |
| let lookup = (0..=10) |
| .into_grouping_map_by(|_| 0) |
| .max_by(|_, _, _| Ordering::Equal); |
| |
| assert_eq!(lookup[&0], 10); |
| |
| let lookup = (0..=10) |
| .into_grouping_map_by(|_| 0) |
| .min_by(|_, _, _| Ordering::Equal); |
| |
| assert_eq!(lookup[&0], 0); |
| |
| let lookup = (0..=10) |
| .into_grouping_map_by(|_| 0) |
| .minmax_by(|_, _, _| Ordering::Equal); |
| |
| assert_eq!(lookup[&0], MinMaxResult::MinMax(0, 10)); |
| } |
| } |
| |
| quickcheck! { |
| fn counts(nums: Vec<isize>) -> TestResult { |
| let counts = nums.iter().counts(); |
| for (&item, &count) in counts.iter() { |
| #[allow(clippy::absurd_extreme_comparisons)] |
| if count <= 0 { |
| return TestResult::failed(); |
| } |
| if count != nums.iter().filter(|&x| x == item).count() { |
| return TestResult::failed(); |
| } |
| } |
| for item in nums.iter() { |
| if !counts.contains_key(item) { |
| return TestResult::failed(); |
| } |
| } |
| TestResult::passed() |
| } |
| } |
| |
| quickcheck! { |
| fn test_double_ended_zip_2(a: Vec<u8>, b: Vec<u8>) -> TestResult { |
| let mut x = |
| multizip((a.clone().into_iter(), b.clone().into_iter())) |
| .collect_vec(); |
| x.reverse(); |
| |
| let y = |
| multizip((a.into_iter(), b.into_iter())) |
| .rfold(Vec::new(), |mut vec, e| { vec.push(e); vec }); |
| |
| TestResult::from_bool(itertools::equal(x, y)) |
| } |
| |
| fn test_double_ended_zip_3(a: Vec<u8>, b: Vec<u8>, c: Vec<u8>) -> TestResult { |
| let mut x = |
| multizip((a.clone().into_iter(), b.clone().into_iter(), c.clone().into_iter())) |
| .collect_vec(); |
| x.reverse(); |
| |
| let y = |
| multizip((a.into_iter(), b.into_iter(), c.into_iter())) |
| .rfold(Vec::new(), |mut vec, e| { vec.push(e); vec }); |
| |
| TestResult::from_bool(itertools::equal(x, y)) |
| } |
| } |
| |
| fn is_fused<I: Iterator>(mut it: I) -> bool { |
| for _ in it.by_ref() {} |
| for _ in 0..10 { |
| if it.next().is_some() { |
| return false; |
| } |
| } |
| true |
| } |
| |
| quickcheck! { |
| fn fused_combination(a: Iter<i16>) -> bool |
| { |
| is_fused(a.clone().combinations(1)) && |
| is_fused(a.combinations(3)) |
| } |
| |
| fn fused_combination_with_replacement(a: Iter<i16>) -> bool |
| { |
| is_fused(a.clone().combinations_with_replacement(1)) && |
| is_fused(a.combinations_with_replacement(3)) |
| } |
| |
| fn fused_tuple_combination(a: Iter<i16>) -> bool |
| { |
| is_fused(a.clone().fuse().tuple_combinations::<(_,)>()) && |
| is_fused(a.fuse().tuple_combinations::<(_,_,_)>()) |
| } |
| |
| fn fused_unique(a: Iter<i16>) -> bool |
| { |
| is_fused(a.fuse().unique()) |
| } |
| |
| fn fused_unique_by(a: Iter<i16>) -> bool |
| { |
| is_fused(a.fuse().unique_by(|x| x % 100)) |
| } |
| |
| fn fused_interleave_shortest(a: Iter<i16>, b: Iter<i16>) -> bool |
| { |
| !is_fused(a.clone().interleave_shortest(b.clone())) && |
| is_fused(a.fuse().interleave_shortest(b.fuse())) |
| } |
| |
| fn fused_product(a: Iter<i16>, b: Iter<i16>) -> bool |
| { |
| is_fused(a.fuse().cartesian_product(b.fuse())) |
| } |
| |
| fn fused_merge(a: Iter<i16>, b: Iter<i16>) -> bool |
| { |
| is_fused(a.fuse().merge(b.fuse())) |
| } |
| |
| fn fused_filter_ok(a: Iter<i16>) -> bool |
| { |
| is_fused(a.map(|x| if x % 2 == 0 {Ok(x)} else {Err(x)} ) |
| .filter_ok(|x| x % 3 == 0) |
| .fuse()) |
| } |
| |
| fn fused_filter_map_ok(a: Iter<i16>) -> bool |
| { |
| is_fused(a.map(|x| if x % 2 == 0 {Ok(x)} else {Err(x)} ) |
| .filter_map_ok(|x| if x % 3 == 0 {Some(x / 3)} else {None}) |
| .fuse()) |
| } |
| |
| fn fused_positions(a: Iter<i16>) -> bool |
| { |
| !is_fused(a.clone().positions(|x|x%2==0)) && |
| is_fused(a.fuse().positions(|x|x%2==0)) |
| } |
| |
| fn fused_update(a: Iter<i16>) -> bool |
| { |
| !is_fused(a.clone().update(|x|*x+=1)) && |
| is_fused(a.fuse().update(|x|*x+=1)) |
| } |
| |
| fn fused_tuple_windows(a: Iter<i16>) -> bool |
| { |
| is_fused(a.fuse().tuple_windows::<(_,_)>()) |
| } |
| |
| fn fused_pad_using(a: Iter<i16>) -> bool |
| { |
| is_fused(a.fuse().pad_using(100,|_|0)) |
| } |
| } |
| |
| quickcheck! { |
| fn min_set_contains_min(a: Vec<(usize, char)>) -> bool { |
| let result_set = a.iter().min_set(); |
| if let Some(result_element) = a.iter().min() { |
| result_set.contains(&result_element) |
| } else { |
| result_set.is_empty() |
| } |
| } |
| |
| fn min_set_by_contains_min(a: Vec<(usize, char)>) -> bool { |
| let compare = |x: &&(usize, char), y: &&(usize, char)| x.1.cmp(&y.1); |
| let result_set = a.iter().min_set_by(compare); |
| if let Some(result_element) = a.iter().min_by(compare) { |
| result_set.contains(&result_element) |
| } else { |
| result_set.is_empty() |
| } |
| } |
| |
| fn min_set_by_key_contains_min(a: Vec<(usize, char)>) -> bool { |
| let key = |x: &&(usize, char)| x.1; |
| let result_set = a.iter().min_set_by_key(&key); |
| if let Some(result_element) = a.iter().min_by_key(&key) { |
| result_set.contains(&result_element) |
| } else { |
| result_set.is_empty() |
| } |
| } |
| |
| fn max_set_contains_max(a: Vec<(usize, char)>) -> bool { |
| let result_set = a.iter().max_set(); |
| if let Some(result_element) = a.iter().max() { |
| result_set.contains(&result_element) |
| } else { |
| result_set.is_empty() |
| } |
| } |
| |
| fn max_set_by_contains_max(a: Vec<(usize, char)>) -> bool { |
| let compare = |x: &&(usize, char), y: &&(usize, char)| x.1.cmp(&y.1); |
| let result_set = a.iter().max_set_by(compare); |
| if let Some(result_element) = a.iter().max_by(compare) { |
| result_set.contains(&result_element) |
| } else { |
| result_set.is_empty() |
| } |
| } |
| |
| fn max_set_by_key_contains_max(a: Vec<(usize, char)>) -> bool { |
| let key = |x: &&(usize, char)| x.1; |
| let result_set = a.iter().max_set_by_key(&key); |
| if let Some(result_element) = a.iter().max_by_key(&key) { |
| result_set.contains(&result_element) |
| } else { |
| result_set.is_empty() |
| } |
| } |
| |
| fn tail(v: Vec<i32>, n: u8) -> bool { |
| let n = n as usize; |
| let result = &v[v.len().saturating_sub(n)..]; |
| itertools::equal(v.iter().tail(n), result) |
| && itertools::equal(v.iter().filter(|_| true).tail(n), result) |
| } |
| } |
