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-rw-r--r--vendor/itertools/tests/test_std.rs1569
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diff --git a/vendor/itertools/tests/test_std.rs b/vendor/itertools/tests/test_std.rs
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+#![allow(unstable_name_collisions)]
+
+use crate::it::cloned;
+use crate::it::free::put_back_n;
+use crate::it::free::rciter;
+use crate::it::iproduct;
+use crate::it::izip;
+use crate::it::multipeek;
+use crate::it::multizip;
+use crate::it::peek_nth;
+use crate::it::repeat_n;
+use crate::it::ExactlyOneError;
+use crate::it::FoldWhile;
+use crate::it::Itertools;
+use itertools as it;
+use quickcheck as qc;
+use rand::{
+ distributions::{Distribution, Standard},
+ rngs::StdRng,
+ Rng, SeedableRng,
+};
+use rand::{seq::SliceRandom, thread_rng};
+use std::{cmp::min, fmt::Debug, marker::PhantomData};
+
+#[test]
+fn product3() {
+ let prod = iproduct!(0..3, 0..2, 0..2);
+ assert_eq!(prod.size_hint(), (12, Some(12)));
+ let v = prod.collect_vec();
+ for i in 0..3 {
+ for j in 0..2 {
+ for k in 0..2 {
+ assert!((i, j, k) == v[(i * 2 * 2 + j * 2 + k) as usize]);
+ }
+ }
+ }
+ for (_, _, _, _) in iproduct!(0..3, 0..2, 0..2, 0..3) { /* test compiles */ }
+}
+
+#[test]
+fn interleave_shortest() {
+ let v0: Vec<i32> = vec![0, 2, 4];
+ let v1: Vec<i32> = vec![1, 3, 5, 7];
+ let it = v0.into_iter().interleave_shortest(v1);
+ assert_eq!(it.size_hint(), (6, Some(6)));
+ assert_eq!(it.collect_vec(), vec![0, 1, 2, 3, 4, 5]);
+
+ let v0: Vec<i32> = vec![0, 2, 4, 6, 8];
+ let v1: Vec<i32> = vec![1, 3, 5];
+ let it = v0.into_iter().interleave_shortest(v1);
+ assert_eq!(it.size_hint(), (7, Some(7)));
+ assert_eq!(it.collect_vec(), vec![0, 1, 2, 3, 4, 5, 6]);
+
+ let i0 = ::std::iter::repeat(0);
+ let v1: Vec<_> = vec![1, 3, 5];
+ let it = i0.interleave_shortest(v1);
+ assert_eq!(it.size_hint(), (7, Some(7)));
+
+ let v0: Vec<_> = vec![0, 2, 4];
+ let i1 = ::std::iter::repeat(1);
+ let it = v0.into_iter().interleave_shortest(i1);
+ assert_eq!(it.size_hint(), (6, Some(6)));
+}
+
+#[test]
+fn duplicates_by() {
+ let xs = ["aaa", "bbbbb", "aa", "ccc", "bbbb", "aaaaa", "cccc"];
+ let ys = ["aa", "bbbb", "cccc"];
+ it::assert_equal(ys.iter(), xs.iter().duplicates_by(|x| x[..2].to_string()));
+ it::assert_equal(
+ ys.iter(),
+ xs.iter().rev().duplicates_by(|x| x[..2].to_string()).rev(),
+ );
+ let ys_rev = ["ccc", "aa", "bbbbb"];
+ it::assert_equal(
+ ys_rev.iter(),
+ xs.iter().duplicates_by(|x| x[..2].to_string()).rev(),
+ );
+}
+
+#[test]
+fn duplicates() {
+ let xs = [0, 1, 2, 3, 2, 1, 3];
+ let ys = [2, 1, 3];
+ it::assert_equal(ys.iter(), xs.iter().duplicates());
+ it::assert_equal(ys.iter(), xs.iter().rev().duplicates().rev());
+ let ys_rev = [3, 2, 1];
+ it::assert_equal(ys_rev.iter(), xs.iter().duplicates().rev());
+
+ let xs = [0, 1, 0, 1];
+ let ys = [0, 1];
+ it::assert_equal(ys.iter(), xs.iter().duplicates());
+ it::assert_equal(ys.iter(), xs.iter().rev().duplicates().rev());
+ let ys_rev = [1, 0];
+ it::assert_equal(ys_rev.iter(), xs.iter().duplicates().rev());
+
+ let xs = [0, 1, 2, 1, 2];
+ let ys = vec![1, 2];
+ assert_eq!(ys, xs.iter().duplicates().cloned().collect_vec());
+ assert_eq!(
+ ys,
+ xs.iter().rev().duplicates().rev().cloned().collect_vec()
+ );
+ let ys_rev = vec![2, 1];
+ assert_eq!(ys_rev, xs.iter().duplicates().rev().cloned().collect_vec());
+}
+
+#[test]
+fn unique_by() {
+ let xs = ["aaa", "bbbbb", "aa", "ccc", "bbbb", "aaaaa", "cccc"];
+ let ys = ["aaa", "bbbbb", "ccc"];
+ it::assert_equal(ys.iter(), xs.iter().unique_by(|x| x[..2].to_string()));
+ it::assert_equal(
+ ys.iter(),
+ xs.iter().rev().unique_by(|x| x[..2].to_string()).rev(),
+ );
+ let ys_rev = ["cccc", "aaaaa", "bbbb"];
+ it::assert_equal(
+ ys_rev.iter(),
+ xs.iter().unique_by(|x| x[..2].to_string()).rev(),
+ );
+}
+
+#[test]
+fn unique() {
+ let xs = [0, 1, 2, 3, 2, 1, 3];
+ let ys = [0, 1, 2, 3];
+ it::assert_equal(ys.iter(), xs.iter().unique());
+ it::assert_equal(ys.iter(), xs.iter().rev().unique().rev());
+ let ys_rev = [3, 1, 2, 0];
+ it::assert_equal(ys_rev.iter(), xs.iter().unique().rev());
+
+ let xs = [0, 1];
+ let ys = [0, 1];
+ it::assert_equal(ys.iter(), xs.iter().unique());
+ it::assert_equal(ys.iter(), xs.iter().rev().unique().rev());
+ let ys_rev = [1, 0];
+ it::assert_equal(ys_rev.iter(), xs.iter().unique().rev());
+}
+
+#[test]
+fn intersperse() {
+ let xs = ["a", "", "b", "c"];
+ let v: Vec<&str> = xs.iter().cloned().intersperse(", ").collect();
+ let text: String = v.concat();
+ assert_eq!(text, "a, , b, c".to_string());
+
+ let ys = [0, 1, 2, 3];
+ let mut it = ys[..0].iter().copied().intersperse(1);
+ assert!(it.next().is_none());
+}
+
+#[test]
+fn dedup() {
+ let xs = [0, 1, 1, 1, 2, 1, 3, 3];
+ let ys = [0, 1, 2, 1, 3];
+ it::assert_equal(ys.iter(), xs.iter().dedup());
+ let xs = [0, 0, 0, 0, 0];
+ let ys = [0];
+ it::assert_equal(ys.iter(), xs.iter().dedup());
+
+ let xs = [0, 1, 1, 1, 2, 1, 3, 3];
+ let ys = [0, 1, 2, 1, 3];
+ let mut xs_d = Vec::new();
+ xs.iter().dedup().fold((), |(), &elt| xs_d.push(elt));
+ assert_eq!(&xs_d, &ys);
+}
+
+#[test]
+fn coalesce() {
+ let data = [-1., -2., -3., 3., 1., 0., -1.];
+ let it = data.iter().cloned().coalesce(|x, y| {
+ if (x >= 0.) == (y >= 0.) {
+ Ok(x + y)
+ } else {
+ Err((x, y))
+ }
+ });
+ itertools::assert_equal(it.clone(), vec![-6., 4., -1.]);
+ assert_eq!(
+ it.fold(vec![], |mut v, n| {
+ v.push(n);
+ v
+ }),
+ vec![-6., 4., -1.]
+ );
+}
+
+#[test]
+fn dedup_by() {
+ let xs = [
+ (0, 0),
+ (0, 1),
+ (1, 1),
+ (2, 1),
+ (0, 2),
+ (3, 1),
+ (0, 3),
+ (1, 3),
+ ];
+ let ys = [(0, 0), (0, 1), (0, 2), (3, 1), (0, 3)];
+ it::assert_equal(ys.iter(), xs.iter().dedup_by(|x, y| x.1 == y.1));
+ let xs = [(0, 1), (0, 2), (0, 3), (0, 4), (0, 5)];
+ let ys = [(0, 1)];
+ it::assert_equal(ys.iter(), xs.iter().dedup_by(|x, y| x.0 == y.0));
+
+ let xs = [
+ (0, 0),
+ (0, 1),
+ (1, 1),
+ (2, 1),
+ (0, 2),
+ (3, 1),
+ (0, 3),
+ (1, 3),
+ ];
+ let ys = [(0, 0), (0, 1), (0, 2), (3, 1), (0, 3)];
+ let mut xs_d = Vec::new();
+ xs.iter()
+ .dedup_by(|x, y| x.1 == y.1)
+ .fold((), |(), &elt| xs_d.push(elt));
+ assert_eq!(&xs_d, &ys);
+}
+
+#[test]
+fn dedup_with_count() {
+ let xs: [i32; 8] = [0, 1, 1, 1, 2, 1, 3, 3];
+ let ys: [(usize, &i32); 5] = [(1, &0), (3, &1), (1, &2), (1, &1), (2, &3)];
+
+ it::assert_equal(ys.iter().cloned(), xs.iter().dedup_with_count());
+
+ let xs: [i32; 5] = [0, 0, 0, 0, 0];
+ let ys: [(usize, &i32); 1] = [(5, &0)];
+
+ it::assert_equal(ys.iter().cloned(), xs.iter().dedup_with_count());
+}
+
+#[test]
+fn dedup_by_with_count() {
+ let xs = [
+ (0, 0),
+ (0, 1),
+ (1, 1),
+ (2, 1),
+ (0, 2),
+ (3, 1),
+ (0, 3),
+ (1, 3),
+ ];
+ let ys = [
+ (1, &(0, 0)),
+ (3, &(0, 1)),
+ (1, &(0, 2)),
+ (1, &(3, 1)),
+ (2, &(0, 3)),
+ ];
+
+ it::assert_equal(
+ ys.iter().cloned(),
+ xs.iter().dedup_by_with_count(|x, y| x.1 == y.1),
+ );
+
+ let xs = [(0, 1), (0, 2), (0, 3), (0, 4), (0, 5)];
+ let ys = [(5, &(0, 1))];
+
+ it::assert_equal(
+ ys.iter().cloned(),
+ xs.iter().dedup_by_with_count(|x, y| x.0 == y.0),
+ );
+}
+
+#[test]
+fn all_equal() {
+ assert!("".chars().all_equal());
+ assert!("A".chars().all_equal());
+ assert!(!"AABBCCC".chars().all_equal());
+ assert!("AAAAAAA".chars().all_equal());
+ for (_key, mut sub) in &"AABBCCC".chars().chunk_by(|&x| x) {
+ assert!(sub.all_equal());
+ }
+}
+
+#[test]
+fn all_equal_value() {
+ assert_eq!("".chars().all_equal_value(), Err(None));
+ assert_eq!("A".chars().all_equal_value(), Ok('A'));
+ assert_eq!("AABBCCC".chars().all_equal_value(), Err(Some(('A', 'B'))));
+ assert_eq!("AAAAAAA".chars().all_equal_value(), Ok('A'));
+ {
+ let mut it = [1, 2, 3].iter().copied();
+ let result = it.all_equal_value();
+ assert_eq!(result, Err(Some((1, 2))));
+ let remaining = it.next();
+ assert_eq!(remaining, Some(3));
+ assert!(it.next().is_none());
+ }
+}
+
+#[test]
+fn all_unique() {
+ assert!("ABCDEFGH".chars().all_unique());
+ assert!(!"ABCDEFGA".chars().all_unique());
+ assert!(::std::iter::empty::<usize>().all_unique());
+}
+
+#[test]
+fn test_put_back_n() {
+ let xs = [0, 1, 1, 1, 2, 1, 3, 3];
+ let mut pb = put_back_n(xs.iter().cloned());
+ pb.next();
+ pb.next();
+ pb.put_back(1);
+ pb.put_back(0);
+ it::assert_equal(pb, xs.iter().cloned());
+}
+
+#[test]
+fn tee() {
+ let xs = [0, 1, 2, 3];
+ let (mut t1, mut t2) = xs.iter().cloned().tee();
+ assert_eq!(t1.next(), Some(0));
+ assert_eq!(t2.next(), Some(0));
+ assert_eq!(t1.next(), Some(1));
+ assert_eq!(t1.next(), Some(2));
+ assert_eq!(t1.next(), Some(3));
+ assert_eq!(t1.next(), None);
+ assert_eq!(t2.next(), Some(1));
+ assert_eq!(t2.next(), Some(2));
+ assert_eq!(t1.next(), None);
+ assert_eq!(t2.next(), Some(3));
+ assert_eq!(t2.next(), None);
+ assert_eq!(t1.next(), None);
+ assert_eq!(t2.next(), None);
+
+ let (t1, t2) = xs.iter().cloned().tee();
+ it::assert_equal(t1, xs.iter().cloned());
+ it::assert_equal(t2, xs.iter().cloned());
+
+ let (t1, t2) = xs.iter().cloned().tee();
+ it::assert_equal(t1.zip(t2), xs.iter().cloned().zip(xs.iter().cloned()));
+}
+
+#[test]
+fn test_rciter() {
+ let xs = [0, 1, 1, 1, 2, 1, 3, 5, 6];
+
+ let mut r1 = rciter(xs.iter().cloned());
+ let mut r2 = r1.clone();
+ assert_eq!(r1.next(), Some(0));
+ assert_eq!(r2.next(), Some(1));
+ let mut z = r1.zip(r2);
+ assert_eq!(z.next(), Some((1, 1)));
+ assert_eq!(z.next(), Some((2, 1)));
+ assert_eq!(z.next(), Some((3, 5)));
+ assert_eq!(z.next(), None);
+
+ // test intoiterator
+ let r1 = rciter(0..5);
+ let mut z = izip!(&r1, r1);
+ assert_eq!(z.next(), Some((0, 1)));
+}
+
+#[test]
+fn trait_pointers() {
+ struct ByRef<'r, I: ?Sized>(&'r mut I);
+
+ impl<'r, X, I> Iterator for ByRef<'r, I>
+ where
+ I: ?Sized + 'r + Iterator<Item = X>,
+ {
+ type Item = X;
+ fn next(&mut self) -> Option<Self::Item> {
+ self.0.next()
+ }
+ }
+
+ let mut it = Box::new(0..10) as Box<dyn Iterator<Item = i32>>;
+ assert_eq!(it.next(), Some(0));
+
+ {
+ let jt: &mut dyn Iterator<Item = i32> = &mut *it;
+ assert_eq!(jt.next(), Some(1));
+
+ {
+ let mut r = ByRef(jt);
+ assert_eq!(r.next(), Some(2));
+ }
+
+ assert_eq!(jt.find_position(|x| *x == 4), Some((1, 4)));
+ jt.for_each(|_| ());
+ }
+}
+
+#[test]
+fn merge_by() {
+ let odd: Vec<(u32, &str)> = vec![(1, "hello"), (3, "world"), (5, "!")];
+ let even = [(2, "foo"), (4, "bar"), (6, "baz")];
+ let expected = [
+ (1, "hello"),
+ (2, "foo"),
+ (3, "world"),
+ (4, "bar"),
+ (5, "!"),
+ (6, "baz"),
+ ];
+ let results = odd.iter().merge_by(even.iter(), |a, b| a.0 <= b.0);
+ it::assert_equal(results, expected.iter());
+}
+
+#[test]
+fn merge_by_btree() {
+ use std::collections::BTreeMap;
+ let mut bt1 = BTreeMap::new();
+ bt1.insert("hello", 1);
+ bt1.insert("world", 3);
+ let mut bt2 = BTreeMap::new();
+ bt2.insert("foo", 2);
+ bt2.insert("bar", 4);
+ let results = bt1.into_iter().merge_by(bt2, |a, b| a.0 <= b.0);
+ let expected = vec![("bar", 4), ("foo", 2), ("hello", 1), ("world", 3)];
+ it::assert_equal(results, expected);
+}
+
+#[test]
+fn kmerge() {
+ let its = (0..4).map(|s| (s..10).step_by(4));
+
+ it::assert_equal(its.kmerge(), 0..10);
+}
+
+#[test]
+fn kmerge_2() {
+ let its = vec![3, 2, 1, 0].into_iter().map(|s| (s..10).step_by(4));
+
+ it::assert_equal(its.kmerge(), 0..10);
+}
+
+#[test]
+fn kmerge_empty() {
+ let its = (0..4).map(|_| 0..0);
+ assert_eq!(its.kmerge().next(), None);
+}
+
+#[test]
+fn kmerge_size_hint() {
+ let its = (0..5).map(|_| (0..10));
+ assert_eq!(its.kmerge().size_hint(), (50, Some(50)));
+}
+
+#[test]
+fn kmerge_empty_size_hint() {
+ let its = (0..5).map(|_| (0..0));
+ assert_eq!(its.kmerge().size_hint(), (0, Some(0)));
+}
+
+#[test]
+fn join() {
+ let many = [1, 2, 3];
+ let one = [1];
+ let none: Vec<i32> = vec![];
+
+ assert_eq!(many.iter().join(", "), "1, 2, 3");
+ assert_eq!(one.iter().join(", "), "1");
+ assert_eq!(none.iter().join(", "), "");
+}
+
+#[test]
+fn sorted_unstable_by() {
+ let sc = [3, 4, 1, 2].iter().cloned().sorted_by(|&a, &b| a.cmp(&b));
+ it::assert_equal(sc, vec![1, 2, 3, 4]);
+
+ let v = (0..5).sorted_unstable_by(|&a, &b| a.cmp(&b).reverse());
+ it::assert_equal(v, vec![4, 3, 2, 1, 0]);
+}
+
+#[test]
+fn sorted_unstable_by_key() {
+ let sc = [3, 4, 1, 2].iter().cloned().sorted_unstable_by_key(|&x| x);
+ it::assert_equal(sc, vec![1, 2, 3, 4]);
+
+ let v = (0..5).sorted_unstable_by_key(|&x| -x);
+ it::assert_equal(v, vec![4, 3, 2, 1, 0]);
+}
+
+#[test]
+fn sorted_by() {
+ let sc = [3, 4, 1, 2].iter().cloned().sorted_by(|&a, &b| a.cmp(&b));
+ it::assert_equal(sc, vec![1, 2, 3, 4]);
+
+ let v = (0..5).sorted_by(|&a, &b| a.cmp(&b).reverse());
+ it::assert_equal(v, vec![4, 3, 2, 1, 0]);
+}
+
+#[cfg(not(miri))]
+qc::quickcheck! {
+ fn k_smallest_range(n: i64, m: u16, k: u16) -> () {
+ // u16 is used to constrain k and m to 0..2¹⁶,
+ // otherwise the test could use too much memory.
+ let (k, m) = (k as usize, m as u64);
+
+ let mut v: Vec<_> = (n..n.saturating_add(m as _)).collect();
+ // Generate a random permutation of n..n+m
+ v.shuffle(&mut thread_rng());
+
+ // Construct the right answers for the top and bottom elements
+ let mut sorted = v.clone();
+ sorted.sort();
+ // how many elements are we checking
+ let num_elements = min(k, m as _);
+
+ // Compute the top and bottom k in various combinations
+ let sorted_smallest = sorted[..num_elements].iter().cloned();
+ let smallest = v.iter().cloned().k_smallest(k);
+ let smallest_by = v.iter().cloned().k_smallest_by(k, Ord::cmp);
+ let smallest_by_key = v.iter().cloned().k_smallest_by_key(k, |&x| x);
+
+ let sorted_largest = sorted[sorted.len() - num_elements..].iter().rev().cloned();
+ let largest = v.iter().cloned().k_largest(k);
+ let largest_by = v.iter().cloned().k_largest_by(k, Ord::cmp);
+ let largest_by_key = v.iter().cloned().k_largest_by_key(k, |&x| x);
+
+ // Check the variations produce the same answers and that they're right
+ it::assert_equal(smallest, sorted_smallest.clone());
+ it::assert_equal(smallest_by, sorted_smallest.clone());
+ it::assert_equal(smallest_by_key, sorted_smallest);
+
+ it::assert_equal(largest, sorted_largest.clone());
+ it::assert_equal(largest_by, sorted_largest.clone());
+ it::assert_equal(largest_by_key, sorted_largest);
+ }
+
+ fn k_smallest_relaxed_range(n: i64, m: u16, k: u16) -> () {
+ // u16 is used to constrain k and m to 0..2¹⁶,
+ // otherwise the test could use too much memory.
+ let (k, m) = (k as usize, m as u64);
+
+ let mut v: Vec<_> = (n..n.saturating_add(m as _)).collect();
+ // Generate a random permutation of n..n+m
+ v.shuffle(&mut thread_rng());
+
+ // Construct the right answers for the top and bottom elements
+ let mut sorted = v.clone();
+ sorted.sort();
+ // how many elements are we checking
+ let num_elements = min(k, m as _);
+
+ // Compute the top and bottom k in various combinations
+ let sorted_smallest = sorted[..num_elements].iter().cloned();
+ let smallest = v.iter().cloned().k_smallest_relaxed(k);
+ let smallest_by = v.iter().cloned().k_smallest_relaxed_by(k, Ord::cmp);
+ let smallest_by_key = v.iter().cloned().k_smallest_relaxed_by_key(k, |&x| x);
+
+ let sorted_largest = sorted[sorted.len() - num_elements..].iter().rev().cloned();
+ let largest = v.iter().cloned().k_largest_relaxed(k);
+ let largest_by = v.iter().cloned().k_largest_relaxed_by(k, Ord::cmp);
+ let largest_by_key = v.iter().cloned().k_largest_relaxed_by_key(k, |&x| x);
+
+ // Check the variations produce the same answers and that they're right
+ it::assert_equal(smallest, sorted_smallest.clone());
+ it::assert_equal(smallest_by, sorted_smallest.clone());
+ it::assert_equal(smallest_by_key, sorted_smallest);
+
+ it::assert_equal(largest, sorted_largest.clone());
+ it::assert_equal(largest_by, sorted_largest.clone());
+ it::assert_equal(largest_by_key, sorted_largest);
+ }
+}
+
+#[derive(Clone, Debug)]
+struct RandIter<T: 'static + Clone + Send, R: 'static + Clone + Rng + SeedableRng + Send = StdRng> {
+ idx: usize,
+ len: usize,
+ rng: R,
+ _t: PhantomData<T>,
+}
+
+impl<T: Clone + Send, R: Clone + Rng + SeedableRng + Send> Iterator for RandIter<T, R>
+where
+ Standard: Distribution<T>,
+{
+ type Item = T;
+ fn next(&mut self) -> Option<T> {
+ if self.idx == self.len {
+ None
+ } else {
+ self.idx += 1;
+ Some(self.rng.gen())
+ }
+ }
+}
+
+impl<T: Clone + Send, R: Clone + Rng + SeedableRng + Send> qc::Arbitrary for RandIter<T, R> {
+ fn arbitrary<G: qc::Gen>(g: &mut G) -> Self {
+ Self {
+ idx: 0,
+ len: g.size(),
+ rng: R::seed_from_u64(g.next_u64()),
+ _t: PhantomData {},
+ }
+ }
+}
+
+// Check that taking the k smallest is the same as
+// sorting then taking the k first elements
+fn k_smallest_sort<I>(i: I, k: u16)
+where
+ I: Iterator + Clone,
+ I::Item: Ord + Debug,
+{
+ let j = i.clone();
+ let i1 = i.clone();
+ let j1 = i.clone();
+ let k = k as usize;
+ it::assert_equal(i.k_smallest(k), j.sorted().take(k));
+ it::assert_equal(i1.k_smallest_relaxed(k), j1.sorted().take(k));
+}
+
+// Similar to `k_smallest_sort` but for our custom heap implementation.
+fn k_smallest_by_sort<I>(i: I, k: u16)
+where
+ I: Iterator + Clone,
+ I::Item: Ord + Debug,
+{
+ let j = i.clone();
+ let i1 = i.clone();
+ let j1 = i.clone();
+ let k = k as usize;
+ it::assert_equal(i.k_smallest_by(k, Ord::cmp), j.sorted().take(k));
+ it::assert_equal(i1.k_smallest_relaxed_by(k, Ord::cmp), j1.sorted().take(k));
+}
+
+macro_rules! generic_test {
+ ($f:ident, $($t:ty),+) => {
+ $(paste::item! {
+ qc::quickcheck! {
+ fn [< $f _ $t >](i: RandIter<$t>, k: u16) -> () {
+ $f(i, k)
+ }
+ }
+ })+
+ };
+}
+
+#[cfg(not(miri))]
+generic_test!(k_smallest_sort, u8, u16, u32, u64, i8, i16, i32, i64);
+#[cfg(not(miri))]
+generic_test!(k_smallest_by_sort, u8, u16, u32, u64, i8, i16, i32, i64);
+
+#[test]
+fn sorted_by_key() {
+ let sc = [3, 4, 1, 2].iter().cloned().sorted_by_key(|&x| x);
+ it::assert_equal(sc, vec![1, 2, 3, 4]);
+
+ let v = (0..5).sorted_by_key(|&x| -x);
+ it::assert_equal(v, vec![4, 3, 2, 1, 0]);
+}
+
+#[test]
+fn sorted_by_cached_key() {
+ // Track calls to key function
+ let mut ncalls = 0;
+
+ let sorted = [3, 4, 1, 2].iter().cloned().sorted_by_cached_key(|&x| {
+ ncalls += 1;
+ x.to_string()
+ });
+ it::assert_equal(sorted, vec![1, 2, 3, 4]);
+ // Check key function called once per element
+ assert_eq!(ncalls, 4);
+
+ let mut ncalls = 0;
+
+ let sorted = (0..5).sorted_by_cached_key(|&x| {
+ ncalls += 1;
+ -x
+ });
+ it::assert_equal(sorted, vec![4, 3, 2, 1, 0]);
+ // Check key function called once per element
+ assert_eq!(ncalls, 5);
+}
+
+#[test]
+fn test_multipeek() {
+ let nums = vec![1u8, 2, 3, 4, 5];
+
+ let mp = multipeek(nums.iter().copied());
+ assert_eq!(nums, mp.collect::<Vec<_>>());
+
+ let mut mp = multipeek(nums.iter().copied());
+ assert_eq!(mp.peek(), Some(&1));
+ assert_eq!(mp.next(), Some(1));
+ assert_eq!(mp.peek(), Some(&2));
+ assert_eq!(mp.peek(), Some(&3));
+ assert_eq!(mp.next(), Some(2));
+ assert_eq!(mp.peek(), Some(&3));
+ assert_eq!(mp.peek(), Some(&4));
+ assert_eq!(mp.peek(), Some(&5));
+ assert_eq!(mp.peek(), None);
+ assert_eq!(mp.next(), Some(3));
+ assert_eq!(mp.next(), Some(4));
+ assert_eq!(mp.peek(), Some(&5));
+ assert_eq!(mp.peek(), None);
+ assert_eq!(mp.next(), Some(5));
+ assert_eq!(mp.next(), None);
+ assert_eq!(mp.peek(), None);
+}
+
+#[test]
+fn test_multipeek_reset() {
+ let data = [1, 2, 3, 4];
+
+ let mut mp = multipeek(cloned(&data));
+ assert_eq!(mp.peek(), Some(&1));
+ assert_eq!(mp.next(), Some(1));
+ assert_eq!(mp.peek(), Some(&2));
+ assert_eq!(mp.peek(), Some(&3));
+ mp.reset_peek();
+ assert_eq!(mp.peek(), Some(&2));
+ assert_eq!(mp.next(), Some(2));
+}
+
+#[test]
+fn test_multipeek_peeking_next() {
+ use crate::it::PeekingNext;
+ let nums = [1u8, 2, 3, 4, 5, 6, 7];
+
+ let mut mp = multipeek(nums.iter().copied());
+ assert_eq!(mp.peeking_next(|&x| x != 0), Some(1));
+ assert_eq!(mp.next(), Some(2));
+ assert_eq!(mp.peek(), Some(&3));
+ assert_eq!(mp.peek(), Some(&4));
+ assert_eq!(mp.peeking_next(|&x| x == 3), Some(3));
+ assert_eq!(mp.peek(), Some(&4));
+ assert_eq!(mp.peeking_next(|&x| x != 4), None);
+ assert_eq!(mp.peeking_next(|&x| x == 4), Some(4));
+ assert_eq!(mp.peek(), Some(&5));
+ assert_eq!(mp.peek(), Some(&6));
+ assert_eq!(mp.peeking_next(|&x| x != 5), None);
+ assert_eq!(mp.peek(), Some(&7));
+ assert_eq!(mp.peeking_next(|&x| x == 5), Some(5));
+ assert_eq!(mp.peeking_next(|&x| x == 6), Some(6));
+ assert_eq!(mp.peek(), Some(&7));
+ assert_eq!(mp.peek(), None);
+ assert_eq!(mp.next(), Some(7));
+ assert_eq!(mp.peek(), None);
+}
+
+#[test]
+fn test_repeat_n_peeking_next() {
+ use crate::it::PeekingNext;
+ let mut rn = repeat_n(0, 5);
+ assert_eq!(rn.peeking_next(|&x| x != 0), None);
+ assert_eq!(rn.peeking_next(|&x| x <= 0), Some(0));
+ assert_eq!(rn.next(), Some(0));
+ assert_eq!(rn.peeking_next(|&x| x <= 0), Some(0));
+ assert_eq!(rn.peeking_next(|&x| x != 0), None);
+ assert_eq!(rn.peeking_next(|&x| x >= 0), Some(0));
+ assert_eq!(rn.next(), Some(0));
+ assert_eq!(rn.peeking_next(|&x| x <= 0), None);
+ assert_eq!(rn.next(), None);
+}
+
+#[test]
+fn test_peek_nth() {
+ let nums = vec![1u8, 2, 3, 4, 5];
+
+ let iter = peek_nth(nums.iter().copied());
+ assert_eq!(nums, iter.collect::<Vec<_>>());
+
+ let mut iter = peek_nth(nums.iter().copied());
+
+ assert_eq!(iter.peek_nth(0), Some(&1));
+ assert_eq!(iter.peek_nth(0), Some(&1));
+ assert_eq!(iter.next(), Some(1));
+
+ assert_eq!(iter.peek_nth(0), Some(&2));
+ assert_eq!(iter.peek_nth(1), Some(&3));
+ assert_eq!(iter.next(), Some(2));
+
+ assert_eq!(iter.peek_nth(0), Some(&3));
+ assert_eq!(iter.peek_nth(1), Some(&4));
+ assert_eq!(iter.peek_nth(2), Some(&5));
+ assert_eq!(iter.peek_nth(3), None);
+
+ assert_eq!(iter.next(), Some(3));
+ assert_eq!(iter.next(), Some(4));
+
+ assert_eq!(iter.peek_nth(0), Some(&5));
+ assert_eq!(iter.peek_nth(1), None);
+ assert_eq!(iter.next(), Some(5));
+ assert_eq!(iter.next(), None);
+
+ assert_eq!(iter.peek_nth(0), None);
+ assert_eq!(iter.peek_nth(1), None);
+}
+
+#[test]
+fn test_peek_nth_peeking_next() {
+ use it::PeekingNext;
+ let nums = [1u8, 2, 3, 4, 5, 6, 7];
+ let mut iter = peek_nth(nums.iter().copied());
+
+ assert_eq!(iter.peeking_next(|&x| x != 0), Some(1));
+ assert_eq!(iter.next(), Some(2));
+
+ assert_eq!(iter.peek_nth(0), Some(&3));
+ assert_eq!(iter.peek_nth(1), Some(&4));
+ assert_eq!(iter.peeking_next(|&x| x == 3), Some(3));
+ assert_eq!(iter.peek(), Some(&4));
+
+ assert_eq!(iter.peeking_next(|&x| x != 4), None);
+ assert_eq!(iter.peeking_next(|&x| x == 4), Some(4));
+ assert_eq!(iter.peek_nth(0), Some(&5));
+ assert_eq!(iter.peek_nth(1), Some(&6));
+
+ assert_eq!(iter.peeking_next(|&x| x != 5), None);
+ assert_eq!(iter.peek(), Some(&5));
+
+ assert_eq!(iter.peeking_next(|&x| x == 5), Some(5));
+ assert_eq!(iter.peeking_next(|&x| x == 6), Some(6));
+ assert_eq!(iter.peek_nth(0), Some(&7));
+ assert_eq!(iter.peek_nth(1), None);
+ assert_eq!(iter.next(), Some(7));
+ assert_eq!(iter.peek(), None);
+}
+
+#[test]
+fn test_peek_nth_next_if() {
+ let nums = [1u8, 2, 3, 4, 5, 6, 7];
+ let mut iter = peek_nth(nums.iter().copied());
+
+ assert_eq!(iter.next_if(|&x| x != 0), Some(1));
+ assert_eq!(iter.next(), Some(2));
+
+ assert_eq!(iter.peek_nth(0), Some(&3));
+ assert_eq!(iter.peek_nth(1), Some(&4));
+ assert_eq!(iter.next_if_eq(&3), Some(3));
+ assert_eq!(iter.peek(), Some(&4));
+
+ assert_eq!(iter.next_if(|&x| x != 4), None);
+ assert_eq!(iter.next_if_eq(&4), Some(4));
+ assert_eq!(iter.peek_nth(0), Some(&5));
+ assert_eq!(iter.peek_nth(1), Some(&6));
+
+ assert_eq!(iter.next_if(|&x| x != 5), None);
+ assert_eq!(iter.peek(), Some(&5));
+
+ assert_eq!(iter.next_if(|&x| x % 2 == 1), Some(5));
+ assert_eq!(iter.next_if_eq(&6), Some(6));
+ assert_eq!(iter.peek_nth(0), Some(&7));
+ assert_eq!(iter.peek_nth(1), None);
+ assert_eq!(iter.next(), Some(7));
+ assert_eq!(iter.peek(), None);
+}
+
+#[test]
+fn pad_using() {
+ it::assert_equal((0..0).pad_using(1, |_| 1), 1..2);
+
+ let v: Vec<usize> = vec![0, 1, 2];
+ let r = v.into_iter().pad_using(5, |n| n);
+ it::assert_equal(r, vec![0, 1, 2, 3, 4]);
+
+ let v: Vec<usize> = vec![0, 1, 2];
+ let r = v.into_iter().pad_using(1, |_| panic!());
+ it::assert_equal(r, vec![0, 1, 2]);
+}
+
+#[test]
+fn chunk_by() {
+ for (ch1, sub) in &"AABBCCC".chars().chunk_by(|&x| x) {
+ for ch2 in sub {
+ assert_eq!(ch1, ch2);
+ }
+ }
+
+ for (ch1, sub) in &"AAABBBCCCCDDDD".chars().chunk_by(|&x| x) {
+ for ch2 in sub {
+ assert_eq!(ch1, ch2);
+ if ch1 == 'C' {
+ break;
+ }
+ }
+ }
+
+ let toupper = |ch: &char| ch.to_uppercase().next().unwrap();
+
+ // try all possible orderings
+ for indices in permutohedron::Heap::new(&mut [0, 1, 2, 3]) {
+ let chunks = "AaaBbbccCcDDDD".chars().chunk_by(&toupper);
+ let mut subs = chunks.into_iter().collect_vec();
+
+ for &idx in &indices[..] {
+ let (key, text) = match idx {
+ 0 => ('A', "Aaa".chars()),
+ 1 => ('B', "Bbb".chars()),
+ 2 => ('C', "ccCc".chars()),
+ 3 => ('D', "DDDD".chars()),
+ _ => unreachable!(),
+ };
+ assert_eq!(key, subs[idx].0);
+ it::assert_equal(&mut subs[idx].1, text);
+ }
+ }
+
+ let chunks = "AAABBBCCCCDDDD".chars().chunk_by(|&x| x);
+ let mut subs = chunks.into_iter().map(|(_, g)| g).collect_vec();
+
+ let sd = subs.pop().unwrap();
+ let sc = subs.pop().unwrap();
+ let sb = subs.pop().unwrap();
+ let sa = subs.pop().unwrap();
+ for (a, b, c, d) in multizip((sa, sb, sc, sd)) {
+ assert_eq!(a, 'A');
+ assert_eq!(b, 'B');
+ assert_eq!(c, 'C');
+ assert_eq!(d, 'D');
+ }
+
+ // check that the key closure is called exactly n times
+ {
+ let mut ntimes = 0;
+ let text = "AABCCC";
+ for (_, sub) in &text.chars().chunk_by(|&x| {
+ ntimes += 1;
+ x
+ }) {
+ for _ in sub {}
+ }
+ assert_eq!(ntimes, text.len());
+ }
+
+ {
+ let mut ntimes = 0;
+ let text = "AABCCC";
+ for _ in &text.chars().chunk_by(|&x| {
+ ntimes += 1;
+ x
+ }) {}
+ assert_eq!(ntimes, text.len());
+ }
+
+ {
+ let text = "ABCCCDEEFGHIJJKK";
+ let gr = text.chars().chunk_by(|&x| x);
+ it::assert_equal(gr.into_iter().flat_map(|(_, sub)| sub), text.chars());
+ }
+}
+
+#[test]
+fn chunk_by_lazy_2() {
+ let data = [0, 1];
+ let chunks = data.iter().chunk_by(|k| *k);
+ let gs = chunks.into_iter().collect_vec();
+ it::assert_equal(data.iter(), gs.into_iter().flat_map(|(_k, g)| g));
+
+ let data = [0, 1, 1, 0, 0];
+ let chunks = data.iter().chunk_by(|k| *k);
+ let mut gs = chunks.into_iter().collect_vec();
+ gs[1..].reverse();
+ it::assert_equal(&[0, 0, 0, 1, 1], gs.into_iter().flat_map(|(_, g)| g));
+
+ let grouper = data.iter().chunk_by(|k| *k);
+ let mut chunks = Vec::new();
+ for (k, chunk) in &grouper {
+ if *k == 1 {
+ chunks.push(chunk);
+ }
+ }
+ it::assert_equal(&mut chunks[0], &[1, 1]);
+
+ let data = [0, 0, 0, 1, 1, 0, 0, 2, 2, 3, 3];
+ let grouper = data.iter().chunk_by(|k| *k);
+ let mut chunks = Vec::new();
+ for (i, (_, chunk)) in grouper.into_iter().enumerate() {
+ if i < 2 {
+ chunks.push(chunk);
+ } else if i < 4 {
+ for _ in chunk {}
+ } else {
+ chunks.push(chunk);
+ }
+ }
+ it::assert_equal(&mut chunks[0], &[0, 0, 0]);
+ it::assert_equal(&mut chunks[1], &[1, 1]);
+ it::assert_equal(&mut chunks[2], &[3, 3]);
+
+ let data = [0, 0, 0, 1, 1, 0, 0, 2, 2, 3, 3];
+ let mut i = 0;
+ let grouper = data.iter().chunk_by(move |_| {
+ let k = i / 3;
+ i += 1;
+ k
+ });
+ for (i, chunk) in &grouper {
+ match i {
+ 0 => it::assert_equal(chunk, &[0, 0, 0]),
+ 1 => it::assert_equal(chunk, &[1, 1, 0]),
+ 2 => it::assert_equal(chunk, &[0, 2, 2]),
+ 3 => it::assert_equal(chunk, &[3, 3]),
+ _ => unreachable!(),
+ }
+ }
+}
+
+#[test]
+fn chunk_by_lazy_3() {
+ // test consuming each chunk on the lap after it was produced
+ let data = [0, 0, 0, 1, 1, 0, 0, 1, 1, 2, 2];
+ let grouper = data.iter().chunk_by(|elt| *elt);
+ let mut last = None;
+ for (key, chunk) in &grouper {
+ if let Some(gr) = last.take() {
+ for elt in gr {
+ assert!(elt != key && i32::abs(elt - key) == 1);
+ }
+ }
+ last = Some(chunk);
+ }
+}
+
+#[test]
+fn chunks() {
+ let data = [0, 0, 0, 1, 1, 0, 0, 2, 2, 3, 3];
+ let grouper = data.iter().chunks(3);
+ for (i, chunk) in grouper.into_iter().enumerate() {
+ match i {
+ 0 => it::assert_equal(chunk, &[0, 0, 0]),
+ 1 => it::assert_equal(chunk, &[1, 1, 0]),
+ 2 => it::assert_equal(chunk, &[0, 2, 2]),
+ 3 => it::assert_equal(chunk, &[3, 3]),
+ _ => unreachable!(),
+ }
+ }
+}
+
+#[test]
+fn concat_empty() {
+ let data: Vec<Vec<()>> = Vec::new();
+ assert_eq!(data.into_iter().concat(), Vec::new())
+}
+
+#[test]
+fn concat_non_empty() {
+ let data = vec![vec![1, 2, 3], vec![4, 5, 6], vec![7, 8, 9]];
+ assert_eq!(data.into_iter().concat(), vec![1, 2, 3, 4, 5, 6, 7, 8, 9])
+}
+
+#[test]
+fn combinations() {
+ assert!((1..3).combinations(5).next().is_none());
+
+ let it = (1..3).combinations(2);
+ it::assert_equal(it, vec![vec![1, 2]]);
+
+ let it = (1..5).combinations(2);
+ it::assert_equal(
+ it,
+ vec![
+ vec![1, 2],
+ vec![1, 3],
+ vec![1, 4],
+ vec![2, 3],
+ vec![2, 4],
+ vec![3, 4],
+ ],
+ );
+
+ it::assert_equal((0..0).tuple_combinations::<(_, _)>(), <Vec<_>>::new());
+ it::assert_equal((0..1).tuple_combinations::<(_, _)>(), <Vec<_>>::new());
+ it::assert_equal((0..2).tuple_combinations::<(_, _)>(), vec![(0, 1)]);
+
+ it::assert_equal((0..0).combinations(2), <Vec<Vec<_>>>::new());
+ it::assert_equal((0..1).combinations(1), vec![vec![0]]);
+ it::assert_equal((0..2).combinations(1), vec![vec![0], vec![1]]);
+ it::assert_equal((0..2).combinations(2), vec![vec![0, 1]]);
+}
+
+#[test]
+fn combinations_of_too_short() {
+ for i in 1..10 {
+ assert!((0..0).combinations(i).next().is_none());
+ assert!((0..i - 1).combinations(i).next().is_none());
+ }
+}
+
+#[test]
+fn combinations_zero() {
+ it::assert_equal((1..3).combinations(0), vec![vec![]]);
+ it::assert_equal((0..0).combinations(0), vec![vec![]]);
+}
+
+fn binomial(n: usize, k: usize) -> usize {
+ if k > n {
+ 0
+ } else {
+ (n - k + 1..=n).product::<usize>() / (1..=k).product::<usize>()
+ }
+}
+
+#[test]
+fn combinations_range_count() {
+ for n in 0..=7 {
+ for k in 0..=7 {
+ let len = binomial(n, k);
+ let mut it = (0..n).combinations(k);
+ assert_eq!(len, it.clone().count());
+ assert_eq!(len, it.size_hint().0);
+ assert_eq!(Some(len), it.size_hint().1);
+ for count in (0..len).rev() {
+ let elem = it.next();
+ assert!(elem.is_some());
+ assert_eq!(count, it.clone().count());
+ assert_eq!(count, it.size_hint().0);
+ assert_eq!(Some(count), it.size_hint().1);
+ }
+ let should_be_none = it.next();
+ assert!(should_be_none.is_none());
+ }
+ }
+}
+
+#[test]
+fn combinations_inexact_size_hints() {
+ for k in 0..=7 {
+ let mut numbers = (0..18).filter(|i| i % 2 == 0); // 9 elements
+ let mut it = numbers.clone().combinations(k);
+ let real_n = numbers.clone().count();
+ let len = binomial(real_n, k);
+ assert_eq!(len, it.clone().count());
+
+ let mut nb_loaded = 0;
+ let sh = numbers.size_hint();
+ assert_eq!(binomial(sh.0 + nb_loaded, k), it.size_hint().0);
+ assert_eq!(sh.1.map(|n| binomial(n + nb_loaded, k)), it.size_hint().1);
+
+ for next_count in 1..=len {
+ let elem = it.next();
+ assert!(elem.is_some());
+ assert_eq!(len - next_count, it.clone().count());
+ if next_count == 1 {
+ // The very first time, the lazy buffer is prefilled.
+ nb_loaded = numbers.by_ref().take(k).count();
+ } else {
+ // Then it loads one item each time until exhausted.
+ let nb = numbers.next();
+ if nb.is_some() {
+ nb_loaded += 1;
+ }
+ }
+ let sh = numbers.size_hint();
+ if next_count > real_n - k + 1 {
+ assert_eq!(0, sh.0);
+ assert_eq!(Some(0), sh.1);
+ assert_eq!(real_n, nb_loaded);
+ // Once it's fully loaded, size hints of `it` are exacts.
+ }
+ assert_eq!(binomial(sh.0 + nb_loaded, k) - next_count, it.size_hint().0);
+ assert_eq!(
+ sh.1.map(|n| binomial(n + nb_loaded, k) - next_count),
+ it.size_hint().1
+ );
+ }
+ let should_be_none = it.next();
+ assert!(should_be_none.is_none());
+ }
+}
+
+#[test]
+fn permutations_zero() {
+ it::assert_equal((1..3).permutations(0), vec![vec![]]);
+ it::assert_equal((0..0).permutations(0), vec![vec![]]);
+}
+
+#[test]
+fn permutations_range_count() {
+ for n in 0..=4 {
+ for k in 0..=4 {
+ let len = if k <= n { (n - k + 1..=n).product() } else { 0 };
+ let mut it = (0..n).permutations(k);
+ assert_eq!(len, it.clone().count());
+ assert_eq!(len, it.size_hint().0);
+ assert_eq!(Some(len), it.size_hint().1);
+ for count in (0..len).rev() {
+ let elem = it.next();
+ assert!(elem.is_some());
+ assert_eq!(count, it.clone().count());
+ assert_eq!(count, it.size_hint().0);
+ assert_eq!(Some(count), it.size_hint().1);
+ }
+ let should_be_none = it.next();
+ assert!(should_be_none.is_none());
+ }
+ }
+}
+
+#[test]
+fn permutations_overflowed_size_hints() {
+ let mut it = std::iter::repeat(()).permutations(2);
+ assert_eq!(it.size_hint().0, usize::MAX);
+ assert_eq!(it.size_hint().1, None);
+ for nb_generated in 1..=1000 {
+ it.next();
+ assert!(it.size_hint().0 >= usize::MAX - nb_generated);
+ assert_eq!(it.size_hint().1, None);
+ }
+}
+
+#[test]
+#[cfg(not(miri))]
+fn combinations_with_replacement() {
+ // Pool smaller than n
+ it::assert_equal((0..1).combinations_with_replacement(2), vec![vec![0, 0]]);
+ // Pool larger than n
+ it::assert_equal(
+ (0..3).combinations_with_replacement(2),
+ vec![
+ vec![0, 0],
+ vec![0, 1],
+ vec![0, 2],
+ vec![1, 1],
+ vec![1, 2],
+ vec![2, 2],
+ ],
+ );
+ // Zero size
+ it::assert_equal((0..3).combinations_with_replacement(0), vec![vec![]]);
+ // Zero size on empty pool
+ it::assert_equal((0..0).combinations_with_replacement(0), vec![vec![]]);
+ // Empty pool
+ it::assert_equal(
+ (0..0).combinations_with_replacement(2),
+ <Vec<Vec<_>>>::new(),
+ );
+}
+
+#[test]
+fn combinations_with_replacement_range_count() {
+ for n in 0..=4 {
+ for k in 0..=4 {
+ let len = binomial(usize::saturating_sub(n + k, 1), k);
+ let mut it = (0..n).combinations_with_replacement(k);
+ assert_eq!(len, it.clone().count());
+ assert_eq!(len, it.size_hint().0);
+ assert_eq!(Some(len), it.size_hint().1);
+ for count in (0..len).rev() {
+ let elem = it.next();
+ assert!(elem.is_some());
+ assert_eq!(count, it.clone().count());
+ assert_eq!(count, it.size_hint().0);
+ assert_eq!(Some(count), it.size_hint().1);
+ }
+ let should_be_none = it.next();
+ assert!(should_be_none.is_none());
+ }
+ }
+}
+
+#[test]
+fn powerset() {
+ it::assert_equal((0..0).powerset(), vec![vec![]]);
+ it::assert_equal((0..1).powerset(), vec![vec![], vec![0]]);
+ it::assert_equal(
+ (0..2).powerset(),
+ vec![vec![], vec![0], vec![1], vec![0, 1]],
+ );
+ it::assert_equal(
+ (0..3).powerset(),
+ vec![
+ vec![],
+ vec![0],
+ vec![1],
+ vec![2],
+ vec![0, 1],
+ vec![0, 2],
+ vec![1, 2],
+ vec![0, 1, 2],
+ ],
+ );
+
+ assert_eq!((0..4).powerset().count(), 1 << 4);
+ assert_eq!((0..8).powerset().count(), 1 << 8);
+ assert_eq!((0..16).powerset().count(), 1 << 16);
+
+ for n in 0..=4 {
+ let mut it = (0..n).powerset();
+ let len = 2_usize.pow(n);
+ assert_eq!(len, it.clone().count());
+ assert_eq!(len, it.size_hint().0);
+ assert_eq!(Some(len), it.size_hint().1);
+ for count in (0..len).rev() {
+ let elem = it.next();
+ assert!(elem.is_some());
+ assert_eq!(count, it.clone().count());
+ assert_eq!(count, it.size_hint().0);
+ assert_eq!(Some(count), it.size_hint().1);
+ }
+ let should_be_none = it.next();
+ assert!(should_be_none.is_none());
+ }
+}
+
+#[test]
+fn diff_mismatch() {
+ let a = [1, 2, 3, 4];
+ let b = vec![1.0, 5.0, 3.0, 4.0];
+ let b_map = b.into_iter().map(|f| f as i32);
+ let diff = it::diff_with(a.iter(), b_map, |a, b| *a == b);
+
+ assert!(match diff {
+ Some(it::Diff::FirstMismatch(1, _, from_diff)) =>
+ from_diff.collect::<Vec<_>>() == vec![5, 3, 4],
+ _ => false,
+ });
+}
+
+#[test]
+fn diff_longer() {
+ let a = [1, 2, 3, 4];
+ let b = vec![1.0, 2.0, 3.0, 4.0, 5.0, 6.0];
+ let b_map = b.into_iter().map(|f| f as i32);
+ let diff = it::diff_with(a.iter(), b_map, |a, b| *a == b);
+
+ assert!(match diff {
+ Some(it::Diff::Longer(_, remaining)) => remaining.collect::<Vec<_>>() == vec![5, 6],
+ _ => false,
+ });
+}
+
+#[test]
+fn diff_shorter() {
+ let a = [1, 2, 3, 4];
+ let b = vec![1.0, 2.0];
+ let b_map = b.into_iter().map(|f| f as i32);
+ let diff = it::diff_with(a.iter(), b_map, |a, b| *a == b);
+
+ assert!(match diff {
+ Some(it::Diff::Shorter(len, _)) => len == 2,
+ _ => false,
+ });
+}
+
+#[test]
+fn extrema_set() {
+ use std::cmp::Ordering;
+
+ // A peculiar type: Equality compares both tuple items, but ordering only the
+ // first item. Used to distinguish equal elements.
+ #[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)
+ }
+ }
+
+ assert_eq!(None::<u32>.iter().min_set(), Vec::<&u32>::new());
+ assert_eq!(None::<u32>.iter().max_set(), Vec::<&u32>::new());
+
+ assert_eq!(Some(1u32).iter().min_set(), vec![&1]);
+ assert_eq!(Some(1u32).iter().max_set(), vec![&1]);
+
+ let data = [Val(0, 1), Val(2, 0), Val(0, 2), Val(1, 0), Val(2, 1)];
+
+ let min_set = data.iter().min_set();
+ assert_eq!(min_set, vec![&Val(0, 1), &Val(0, 2)]);
+
+ let min_set_by_key = data.iter().min_set_by_key(|v| v.1);
+ assert_eq!(min_set_by_key, vec![&Val(2, 0), &Val(1, 0)]);
+
+ let min_set_by = data.iter().min_set_by(|x, y| x.1.cmp(&y.1));
+ assert_eq!(min_set_by, vec![&Val(2, 0), &Val(1, 0)]);
+
+ let max_set = data.iter().max_set();
+ assert_eq!(max_set, vec![&Val(2, 0), &Val(2, 1)]);
+
+ let max_set_by_key = data.iter().max_set_by_key(|v| v.1);
+ assert_eq!(max_set_by_key, vec![&Val(0, 2)]);
+
+ let max_set_by = data.iter().max_set_by(|x, y| x.1.cmp(&y.1));
+ assert_eq!(max_set_by, vec![&Val(0, 2)]);
+}
+
+#[test]
+fn minmax() {
+ use crate::it::MinMaxResult;
+ use std::cmp::Ordering;
+
+ // 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)
+ }
+ }
+
+ assert_eq!(
+ None::<Option<u32>>.iter().minmax(),
+ MinMaxResult::NoElements
+ );
+
+ assert_eq!(Some(1u32).iter().minmax(), MinMaxResult::OneElement(&1));
+
+ let data = [Val(0, 1), Val(2, 0), Val(0, 2), Val(1, 0), Val(2, 1)];
+
+ let minmax = data.iter().minmax();
+ assert_eq!(minmax, MinMaxResult::MinMax(&Val(0, 1), &Val(2, 1)));
+
+ let (min, max) = data.iter().minmax_by_key(|v| v.1).into_option().unwrap();
+ assert_eq!(min, &Val(2, 0));
+ assert_eq!(max, &Val(0, 2));
+
+ let (min, max) = data
+ .iter()
+ .minmax_by(|x, y| x.1.cmp(&y.1))
+ .into_option()
+ .unwrap();
+ assert_eq!(min, &Val(2, 0));
+ assert_eq!(max, &Val(0, 2));
+}
+
+#[test]
+fn format() {
+ let data = [0, 1, 2, 3];
+ let ans1 = "0, 1, 2, 3";
+ let ans2 = "0--1--2--3";
+
+ let t1 = format!("{}", data.iter().format(", "));
+ assert_eq!(t1, ans1);
+ let t2 = format!("{:?}", data.iter().format("--"));
+ assert_eq!(t2, ans2);
+
+ let dataf = [1.1, 5.71828, -22.];
+ let t3 = format!("{:.2e}", dataf.iter().format(", "));
+ assert_eq!(t3, "1.10e0, 5.72e0, -2.20e1");
+}
+
+#[test]
+fn while_some() {
+ let ns = (1..10)
+ .map(|x| if x % 5 != 0 { Some(x) } else { None })
+ .while_some();
+ it::assert_equal(ns, vec![1, 2, 3, 4]);
+}
+
+#[test]
+fn fold_while() {
+ let mut iterations = 0;
+ let vec = vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
+ let sum = vec
+ .into_iter()
+ .fold_while(0, |acc, item| {
+ iterations += 1;
+ let new_sum = acc + item;
+ if new_sum <= 20 {
+ FoldWhile::Continue(new_sum)
+ } else {
+ FoldWhile::Done(acc)
+ }
+ })
+ .into_inner();
+ assert_eq!(iterations, 6);
+ assert_eq!(sum, 15);
+}
+
+#[test]
+fn tree_reduce() {
+ let x = [
+ "",
+ "0",
+ "0 1 x",
+ "0 1 x 2 x",
+ "0 1 x 2 3 x x",
+ "0 1 x 2 3 x x 4 x",
+ "0 1 x 2 3 x x 4 5 x x",
+ "0 1 x 2 3 x x 4 5 x 6 x x",
+ "0 1 x 2 3 x x 4 5 x 6 7 x x x",
+ "0 1 x 2 3 x x 4 5 x 6 7 x x x 8 x",
+ "0 1 x 2 3 x x 4 5 x 6 7 x x x 8 9 x x",
+ "0 1 x 2 3 x x 4 5 x 6 7 x x x 8 9 x 10 x x",
+ "0 1 x 2 3 x x 4 5 x 6 7 x x x 8 9 x 10 11 x x x",
+ "0 1 x 2 3 x x 4 5 x 6 7 x x x 8 9 x 10 11 x x 12 x x",
+ "0 1 x 2 3 x x 4 5 x 6 7 x x x 8 9 x 10 11 x x 12 13 x x x",
+ "0 1 x 2 3 x x 4 5 x 6 7 x x x 8 9 x 10 11 x x 12 13 x 14 x x x",
+ "0 1 x 2 3 x x 4 5 x 6 7 x x x 8 9 x 10 11 x x 12 13 x 14 15 x x x x",
+ ];
+ for (i, &s) in x.iter().enumerate() {
+ let expected = if s.is_empty() {
+ None
+ } else {
+ Some(s.to_string())
+ };
+ let num_strings = (0..i).map(|x| x.to_string());
+ let actual = num_strings.tree_reduce(|a, b| format!("{} {} x", a, b));
+ assert_eq!(actual, expected);
+ }
+}
+
+#[test]
+fn exactly_one_question_mark_syntax_works() {
+ exactly_one_question_mark_return().unwrap_err();
+}
+
+fn exactly_one_question_mark_return() -> Result<(), ExactlyOneError<std::slice::Iter<'static, ()>>>
+{
+ [].iter().exactly_one()?;
+ Ok(())
+}
+
+#[test]
+fn multiunzip() {
+ let (a, b, c): (Vec<_>, Vec<_>, Vec<_>) = [(0, 1, 2), (3, 4, 5), (6, 7, 8)]
+ .iter()
+ .cloned()
+ .multiunzip();
+ assert_eq!((a, b, c), (vec![0, 3, 6], vec![1, 4, 7], vec![2, 5, 8]));
+ let (): () = [(), (), ()].iter().cloned().multiunzip();
+ #[allow(clippy::type_complexity)]
+ let t: (
+ Vec<_>,
+ Vec<_>,
+ Vec<_>,
+ Vec<_>,
+ Vec<_>,
+ Vec<_>,
+ Vec<_>,
+ Vec<_>,
+ Vec<_>,
+ Vec<_>,
+ Vec<_>,
+ Vec<_>,
+ ) = [(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11)]
+ .iter()
+ .cloned()
+ .multiunzip();
+ assert_eq!(
+ t,
+ (
+ vec![0],
+ vec![1],
+ vec![2],
+ vec![3],
+ vec![4],
+ vec![5],
+ vec![6],
+ vec![7],
+ vec![8],
+ vec![9],
+ vec![10],
+ vec![11]
+ )
+ );
+}
generated by cgit v1.2.3 (git 2.39.1) at 2026-02-02 18:30:23 +0000