1 // Copyright 2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
12 use core::iter::order::*;
13 use core::iter::MinMaxResult::*;
22 let empty: [isize; 0] = [];
26 assert!(!lt(xs.iter(), ys.iter()));
27 assert!(!le(xs.iter(), ys.iter()));
28 assert!( gt(xs.iter(), ys.iter()));
29 assert!( ge(xs.iter(), ys.iter()));
31 assert!( lt(ys.iter(), xs.iter()));
32 assert!( le(ys.iter(), xs.iter()));
33 assert!(!gt(ys.iter(), xs.iter()));
34 assert!(!ge(ys.iter(), xs.iter()));
36 assert!( lt(empty.iter(), xs.iter()));
37 assert!( le(empty.iter(), xs.iter()));
38 assert!(!gt(empty.iter(), xs.iter()));
39 assert!(!ge(empty.iter(), xs.iter()));
42 let u = [1.0f64, 2.0];
43 let v = [0.0f64/0.0, 3.0];
45 assert!(!lt(u.iter(), v.iter()));
46 assert!(!le(u.iter(), v.iter()));
47 assert!(!gt(u.iter(), v.iter()));
48 assert!(!ge(u.iter(), v.iter()));
54 assert!(lt(a.iter(), b.iter()) == (a[0] < b[0]));
55 assert!(le(a.iter(), b.iter()) == (a[0] <= b[0]));
56 assert!(gt(a.iter(), b.iter()) == (a[0] > b[0]));
57 assert!(ge(a.iter(), b.iter()) == (a[0] >= b[0]));
59 assert!(lt(c.iter(), b.iter()) == (c[0] < b[0]));
60 assert!(le(c.iter(), b.iter()) == (c[0] <= b[0]));
61 assert!(gt(c.iter(), b.iter()) == (c[0] > b[0]));
62 assert!(ge(c.iter(), b.iter()) == (c[0] >= b[0]));
66 fn test_multi_iter() {
69 assert!(eq(xs.iter(), ys.iter().rev()));
70 assert!(lt(xs.iter(), xs.iter().skip(2)));
74 fn test_counter_from_iter() {
75 let it = (0..).step_by(5).take(10);
76 let xs: Vec<isize> = FromIterator::from_iter(it);
77 assert_eq!(xs, [0, 5, 10, 15, 20, 25, 30, 35, 40, 45]);
81 fn test_iterator_chain() {
82 let xs = [0, 1, 2, 3, 4, 5];
83 let ys = [30, 40, 50, 60];
84 let expected = [0, 1, 2, 3, 4, 5, 30, 40, 50, 60];
85 let it = xs.iter().chain(ys.iter());
88 assert_eq!(x, expected[i]);
91 assert_eq!(i, expected.len());
93 let ys = (30..).step_by(10).take(4);
94 let it = xs.iter().cloned().chain(ys);
97 assert_eq!(x, expected[i]);
100 assert_eq!(i, expected.len());
104 fn test_filter_map() {
105 let it = (0..).step_by(1).take(10)
106 .filter_map(|x| if x % 2 == 0 { Some(x*x) } else { None });
107 assert_eq!(it.collect::<Vec<usize>>(), [0*0, 2*2, 4*4, 6*6, 8*8]);
111 fn test_iterator_enumerate() {
112 let xs = [0, 1, 2, 3, 4, 5];
113 let it = xs.iter().enumerate();
120 fn test_iterator_peekable() {
121 let xs = vec![0, 1, 2, 3, 4, 5];
122 let mut it = xs.iter().cloned().peekable();
124 assert_eq!(it.len(), 6);
125 assert_eq!(it.peek().unwrap(), &0);
126 assert_eq!(it.len(), 6);
127 assert_eq!(it.next().unwrap(), 0);
128 assert_eq!(it.len(), 5);
129 assert_eq!(it.next().unwrap(), 1);
130 assert_eq!(it.len(), 4);
131 assert_eq!(it.next().unwrap(), 2);
132 assert_eq!(it.len(), 3);
133 assert_eq!(it.peek().unwrap(), &3);
134 assert_eq!(it.len(), 3);
135 assert_eq!(it.peek().unwrap(), &3);
136 assert_eq!(it.len(), 3);
137 assert_eq!(it.next().unwrap(), 3);
138 assert_eq!(it.len(), 2);
139 assert_eq!(it.next().unwrap(), 4);
140 assert_eq!(it.len(), 1);
141 assert_eq!(it.peek().unwrap(), &5);
142 assert_eq!(it.len(), 1);
143 assert_eq!(it.next().unwrap(), 5);
144 assert_eq!(it.len(), 0);
145 assert!(it.peek().is_none());
146 assert_eq!(it.len(), 0);
147 assert!(it.next().is_none());
148 assert_eq!(it.len(), 0);
152 fn test_iterator_take_while() {
153 let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19];
154 let ys = [0, 1, 2, 3, 5, 13];
155 let it = xs.iter().take_while(|&x| *x < 15);
158 assert_eq!(*x, ys[i]);
161 assert_eq!(i, ys.len());
165 fn test_iterator_skip_while() {
166 let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19];
167 let ys = [15, 16, 17, 19];
168 let it = xs.iter().skip_while(|&x| *x < 15);
171 assert_eq!(*x, ys[i]);
174 assert_eq!(i, ys.len());
178 fn test_iterator_skip() {
179 let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19, 20, 30];
180 let ys = [13, 15, 16, 17, 19, 20, 30];
181 let mut it = xs.iter().skip(5);
183 while let Some(&x) = it.next() {
184 assert_eq!(x, ys[i]);
186 assert_eq!(it.len(), xs.len()-5-i);
188 assert_eq!(i, ys.len());
189 assert_eq!(it.len(), 0);
193 fn test_iterator_take() {
194 let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19];
195 let ys = [0, 1, 2, 3, 5];
196 let mut it = xs.iter().take(5);
198 assert_eq!(it.len(), 5);
199 while let Some(&x) = it.next() {
200 assert_eq!(x, ys[i]);
202 assert_eq!(it.len(), 5-i);
204 assert_eq!(i, ys.len());
205 assert_eq!(it.len(), 0);
209 fn test_iterator_take_short() {
210 let xs = [0, 1, 2, 3];
211 let ys = [0, 1, 2, 3];
212 let mut it = xs.iter().take(5);
214 assert_eq!(it.len(), 4);
215 while let Some(&x) = it.next() {
216 assert_eq!(x, ys[i]);
218 assert_eq!(it.len(), 4-i);
220 assert_eq!(i, ys.len());
221 assert_eq!(it.len(), 0);
225 fn test_iterator_scan() {
226 // test the type inference
227 fn add(old: &mut isize, new: &usize) -> Option<f64> {
228 *old += *new as isize;
231 let xs = [0, 1, 2, 3, 4];
232 let ys = [0f64, 1.0, 3.0, 6.0, 10.0];
234 let it = xs.iter().scan(0, add);
237 assert_eq!(x, ys[i]);
240 assert_eq!(i, ys.len());
244 fn test_iterator_flat_map() {
246 let ys = [0, 1, 2, 3, 4, 5, 6, 7, 8];
247 let it = xs.iter().flat_map(|&x| (x..).step_by(1).take(3));
250 assert_eq!(x, ys[i]);
253 assert_eq!(i, ys.len());
258 let xs = [1, 2, 3, 4];
264 .collect::<Vec<usize>>();
266 assert_eq!(n, xs.len());
267 assert_eq!(&xs[..], &ys[..]);
272 fn count(st: &mut usize) -> Option<usize> {
282 let it = Unfold::new(0, count);
285 assert_eq!(counted, i);
294 let it = (0..).step_by(1).take(cycle_len).cycle();
295 assert_eq!(it.size_hint(), (usize::MAX, None));
296 for (i, x) in it.take(100).enumerate() {
297 assert_eq!(i % cycle_len, x);
300 let mut it = (0..).step_by(1).take(0).cycle();
301 assert_eq!(it.size_hint(), (0, Some(0)));
302 assert_eq!(it.next(), None);
306 fn test_iterator_nth() {
307 let v: &[_] = &[0, 1, 2, 3, 4];
308 for i in 0..v.len() {
309 assert_eq!(v.iter().nth(i).unwrap(), &v[i]);
311 assert_eq!(v.iter().nth(v.len()), None);
315 fn test_iterator_last() {
316 let v: &[_] = &[0, 1, 2, 3, 4];
317 assert_eq!(v.iter().last().unwrap(), &4);
318 assert_eq!(v[..1].iter().last().unwrap(), &0);
322 fn test_iterator_len() {
323 let v: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
324 assert_eq!(v[..4].iter().count(), 4);
325 assert_eq!(v[..10].iter().count(), 10);
326 assert_eq!(v[..0].iter().count(), 0);
330 fn test_iterator_sum() {
331 let v: &[i32] = &[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
332 assert_eq!(v[..4].iter().cloned().sum::<i32>(), 6);
333 assert_eq!(v.iter().cloned().sum::<i32>(), 55);
334 assert_eq!(v[..0].iter().cloned().sum::<i32>(), 0);
338 fn test_iterator_product() {
339 let v: &[i32] = &[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
340 assert_eq!(v[..4].iter().cloned().product::<i32>(), 0);
341 assert_eq!(v[1..5].iter().cloned().product::<i32>(), 24);
342 assert_eq!(v[..0].iter().cloned().product::<i32>(), 1);
346 fn test_iterator_max() {
347 let v: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
348 assert_eq!(v[..4].iter().cloned().max(), Some(3));
349 assert_eq!(v.iter().cloned().max(), Some(10));
350 assert_eq!(v[..0].iter().cloned().max(), None);
354 fn test_iterator_min() {
355 let v: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
356 assert_eq!(v[..4].iter().cloned().min(), Some(0));
357 assert_eq!(v.iter().cloned().min(), Some(0));
358 assert_eq!(v[..0].iter().cloned().min(), None);
362 fn test_iterator_size_hint() {
363 let c = (0..).step_by(1);
364 let v: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
365 let v2 = &[10, 11, 12];
368 assert_eq!(c.size_hint(), (usize::MAX, None));
369 assert_eq!(vi.clone().size_hint(), (10, Some(10)));
371 assert_eq!(c.clone().take(5).size_hint(), (5, Some(5)));
372 assert_eq!(c.clone().skip(5).size_hint().1, None);
373 assert_eq!(c.clone().take_while(|_| false).size_hint(), (0, None));
374 assert_eq!(c.clone().skip_while(|_| false).size_hint(), (0, None));
375 assert_eq!(c.clone().enumerate().size_hint(), (usize::MAX, None));
376 assert_eq!(c.clone().chain(vi.clone().cloned()).size_hint(), (usize::MAX, None));
377 assert_eq!(c.clone().zip(vi.clone()).size_hint(), (10, Some(10)));
378 assert_eq!(c.clone().scan(0, |_,_| Some(0)).size_hint(), (0, None));
379 assert_eq!(c.clone().filter(|_| false).size_hint(), (0, None));
380 assert_eq!(c.clone().map(|_| 0).size_hint(), (usize::MAX, None));
381 assert_eq!(c.filter_map(|_| Some(0)).size_hint(), (0, None));
383 assert_eq!(vi.clone().take(5).size_hint(), (5, Some(5)));
384 assert_eq!(vi.clone().take(12).size_hint(), (10, Some(10)));
385 assert_eq!(vi.clone().skip(3).size_hint(), (7, Some(7)));
386 assert_eq!(vi.clone().skip(12).size_hint(), (0, Some(0)));
387 assert_eq!(vi.clone().take_while(|_| false).size_hint(), (0, Some(10)));
388 assert_eq!(vi.clone().skip_while(|_| false).size_hint(), (0, Some(10)));
389 assert_eq!(vi.clone().enumerate().size_hint(), (10, Some(10)));
390 assert_eq!(vi.clone().chain(v2.iter()).size_hint(), (13, Some(13)));
391 assert_eq!(vi.clone().zip(v2.iter()).size_hint(), (3, Some(3)));
392 assert_eq!(vi.clone().scan(0, |_,_| Some(0)).size_hint(), (0, Some(10)));
393 assert_eq!(vi.clone().filter(|_| false).size_hint(), (0, Some(10)));
394 assert_eq!(vi.clone().map(|&i| i+1).size_hint(), (10, Some(10)));
395 assert_eq!(vi.filter_map(|_| Some(0)).size_hint(), (0, Some(10)));
400 let a = vec![1, 2, 3, 4, 5];
401 let b: Vec<isize> = a.iter().cloned().collect();
407 // FIXME (#22405): Replace `Box::new` with `box` here when/if possible.
408 let v: Box<[isize]> = Box::new([1, 2, 3, 4, 5]);
409 assert!(v.iter().all(|&x| x < 10));
410 assert!(!v.iter().all(|&x| x % 2 == 0));
411 assert!(!v.iter().all(|&x| x > 100));
412 assert!(v[..0].iter().all(|_| panic!()));
417 // FIXME (#22405): Replace `Box::new` with `box` here when/if possible.
418 let v: Box<[isize]> = Box::new([1, 2, 3, 4, 5]);
419 assert!(v.iter().any(|&x| x < 10));
420 assert!(v.iter().any(|&x| x % 2 == 0));
421 assert!(!v.iter().any(|&x| x > 100));
422 assert!(!v[..0].iter().any(|_| panic!()));
427 let v: &[isize] = &[1, 3, 9, 27, 103, 14, 11];
428 assert_eq!(*v.iter().find(|&&x| x & 1 == 0).unwrap(), 14);
429 assert_eq!(*v.iter().find(|&&x| x % 3 == 0).unwrap(), 3);
430 assert!(v.iter().find(|&&x| x % 12 == 0).is_none());
435 let v = &[1, 3, 9, 27, 103, 14, 11];
436 assert_eq!(v.iter().position(|x| *x & 1 == 0).unwrap(), 5);
437 assert_eq!(v.iter().position(|x| *x % 3 == 0).unwrap(), 1);
438 assert!(v.iter().position(|x| *x % 12 == 0).is_none());
443 let xs = &[1, 2, 2, 1, 5, 9, 0, 2];
444 assert_eq!(xs.iter().filter(|x| **x == 2).count(), 3);
445 assert_eq!(xs.iter().filter(|x| **x == 5).count(), 1);
446 assert_eq!(xs.iter().filter(|x| **x == 95).count(), 0);
451 let xs: &[isize] = &[-3, 0, 1, 5, -10];
452 assert_eq!(*xs.iter().max_by(|x| x.abs()).unwrap(), -10);
457 let xs: &[isize] = &[-3, 0, 1, 5, -10];
458 assert_eq!(*xs.iter().min_by(|x| x.abs()).unwrap(), 0);
464 // sum the first five values
465 let partial_sum = xs.by_ref().take(5).fold(0, |a, b| a + b);
466 assert_eq!(partial_sum, 10);
467 assert_eq!(xs.next(), Some(5));
472 let xs = [2, 4, 6, 8, 10, 12, 14, 16];
473 let mut it = xs.iter();
476 assert!(it.rev().cloned().collect::<Vec<isize>>() ==
477 vec![16, 14, 12, 10, 8, 6]);
482 let xs = [2u8, 4, 6, 8];
484 let mut it = xs.iter().cloned();
485 assert_eq!(it.len(), 4);
486 assert_eq!(it.next(), Some(2));
487 assert_eq!(it.len(), 3);
488 assert_eq!(it.next(), Some(4));
489 assert_eq!(it.len(), 2);
490 assert_eq!(it.next_back(), Some(8));
491 assert_eq!(it.len(), 1);
492 assert_eq!(it.next_back(), Some(6));
493 assert_eq!(it.len(), 0);
494 assert_eq!(it.next_back(), None);
498 fn test_double_ended_map() {
499 let xs = [1, 2, 3, 4, 5, 6];
500 let mut it = xs.iter().map(|&x| x * -1);
501 assert_eq!(it.next(), Some(-1));
502 assert_eq!(it.next(), Some(-2));
503 assert_eq!(it.next_back(), Some(-6));
504 assert_eq!(it.next_back(), Some(-5));
505 assert_eq!(it.next(), Some(-3));
506 assert_eq!(it.next_back(), Some(-4));
507 assert_eq!(it.next(), None);
511 fn test_double_ended_enumerate() {
512 let xs = [1, 2, 3, 4, 5, 6];
513 let mut it = xs.iter().cloned().enumerate();
514 assert_eq!(it.next(), Some((0, 1)));
515 assert_eq!(it.next(), Some((1, 2)));
516 assert_eq!(it.next_back(), Some((5, 6)));
517 assert_eq!(it.next_back(), Some((4, 5)));
518 assert_eq!(it.next_back(), Some((3, 4)));
519 assert_eq!(it.next_back(), Some((2, 3)));
520 assert_eq!(it.next(), None);
524 fn test_double_ended_zip() {
525 let xs = [1, 2, 3, 4, 5, 6];
526 let ys = [1, 2, 3, 7];
527 let a = xs.iter().cloned();
528 let b = ys.iter().cloned();
529 let mut it = a.zip(b);
530 assert_eq!(it.next(), Some((1, 1)));
531 assert_eq!(it.next(), Some((2, 2)));
532 assert_eq!(it.next_back(), Some((4, 7)));
533 assert_eq!(it.next_back(), Some((3, 3)));
534 assert_eq!(it.next(), None);
538 fn test_double_ended_filter() {
539 let xs = [1, 2, 3, 4, 5, 6];
540 let mut it = xs.iter().filter(|&x| *x & 1 == 0);
541 assert_eq!(it.next_back().unwrap(), &6);
542 assert_eq!(it.next_back().unwrap(), &4);
543 assert_eq!(it.next().unwrap(), &2);
544 assert_eq!(it.next_back(), None);
548 fn test_double_ended_filter_map() {
549 let xs = [1, 2, 3, 4, 5, 6];
550 let mut it = xs.iter().filter_map(|&x| if x & 1 == 0 { Some(x * 2) } else { None });
551 assert_eq!(it.next_back().unwrap(), 12);
552 assert_eq!(it.next_back().unwrap(), 8);
553 assert_eq!(it.next().unwrap(), 4);
554 assert_eq!(it.next_back(), None);
558 fn test_double_ended_chain() {
559 let xs = [1, 2, 3, 4, 5];
561 let mut it = xs.iter().chain(ys.iter()).rev();
562 assert_eq!(it.next().unwrap(), &11);
563 assert_eq!(it.next().unwrap(), &9);
564 assert_eq!(it.next_back().unwrap(), &1);
565 assert_eq!(it.next_back().unwrap(), &2);
566 assert_eq!(it.next_back().unwrap(), &3);
567 assert_eq!(it.next_back().unwrap(), &4);
568 assert_eq!(it.next_back().unwrap(), &5);
569 assert_eq!(it.next_back().unwrap(), &7);
570 assert_eq!(it.next_back(), None);
574 fn test_rposition() {
575 fn f(xy: &(isize, char)) -> bool { let (_x, y) = *xy; y == 'b' }
576 fn g(xy: &(isize, char)) -> bool { let (_x, y) = *xy; y == 'd' }
577 let v = [(0, 'a'), (1, 'b'), (2, 'c'), (3, 'b')];
579 assert_eq!(v.iter().rposition(f), Some(3));
580 assert!(v.iter().rposition(g).is_none());
585 fn test_rposition_panic() {
586 let v: [(Box<_>, Box<_>); 4] =
587 [(box 0, box 0), (box 0, box 0),
588 (box 0, box 0), (box 0, box 0)];
590 v.iter().rposition(|_elt| {
601 fn check_randacc_iter<A, T>(a: T, len: usize) where
603 T: Clone + RandomAccessIterator + Iterator<Item=A>,
605 let mut b = a.clone();
606 assert_eq!(len, b.indexable());
608 for (i, elt) in a.enumerate() {
609 assert!(Some(elt) == b.idx(i));
613 assert!(None == b.idx(n));
614 // call recursively to check after picking off an element
617 check_randacc_iter(b, len-1);
623 fn test_double_ended_flat_map() {
626 let mut it = u.iter().flat_map(|x| v[*x..v.len()].iter());
627 assert_eq!(it.next_back().unwrap(), &8);
628 assert_eq!(it.next().unwrap(), &5);
629 assert_eq!(it.next_back().unwrap(), &7);
630 assert_eq!(it.next_back().unwrap(), &6);
631 assert_eq!(it.next_back().unwrap(), &8);
632 assert_eq!(it.next().unwrap(), &6);
633 assert_eq!(it.next_back().unwrap(), &7);
634 assert_eq!(it.next_back(), None);
635 assert_eq!(it.next(), None);
636 assert_eq!(it.next_back(), None);
640 fn test_random_access_chain() {
641 let xs = [1, 2, 3, 4, 5];
643 let mut it = xs.iter().chain(ys.iter());
644 assert_eq!(it.idx(0).unwrap(), &1);
645 assert_eq!(it.idx(5).unwrap(), &7);
646 assert_eq!(it.idx(7).unwrap(), &11);
647 assert!(it.idx(8).is_none());
653 assert_eq!(it.idx(0).unwrap(), &3);
654 assert_eq!(it.idx(4).unwrap(), &9);
655 assert!(it.idx(6).is_none());
657 check_randacc_iter(it, xs.len() + ys.len() - 3);
661 fn test_random_access_enumerate() {
662 let xs = [1, 2, 3, 4, 5];
663 check_randacc_iter(xs.iter().enumerate(), xs.len());
667 fn test_random_access_rev() {
668 let xs = [1, 2, 3, 4, 5];
669 check_randacc_iter(xs.iter().rev(), xs.len());
670 let mut it = xs.iter().rev();
674 check_randacc_iter(it, xs.len() - 3);
678 fn test_random_access_zip() {
679 let xs = [1, 2, 3, 4, 5];
681 check_randacc_iter(xs.iter().zip(ys.iter()), cmp::min(xs.len(), ys.len()));
685 fn test_random_access_take() {
686 let xs = [1, 2, 3, 4, 5];
687 let empty: &[isize] = &[];
688 check_randacc_iter(xs.iter().take(3), 3);
689 check_randacc_iter(xs.iter().take(20), xs.len());
690 check_randacc_iter(xs.iter().take(0), 0);
691 check_randacc_iter(empty.iter().take(2), 0);
695 fn test_random_access_skip() {
696 let xs = [1, 2, 3, 4, 5];
697 let empty: &[isize] = &[];
698 check_randacc_iter(xs.iter().skip(2), xs.len() - 2);
699 check_randacc_iter(empty.iter().skip(2), 0);
703 fn test_random_access_inspect() {
704 let xs = [1, 2, 3, 4, 5];
706 // test .map and .inspect that don't implement Clone
707 let mut it = xs.iter().inspect(|_| {});
708 assert_eq!(xs.len(), it.indexable());
709 for (i, elt) in xs.iter().enumerate() {
710 assert_eq!(Some(elt), it.idx(i));
716 fn test_random_access_map() {
717 let xs = [1, 2, 3, 4, 5];
719 let mut it = xs.iter().cloned();
720 assert_eq!(xs.len(), it.indexable());
721 for (i, elt) in xs.iter().enumerate() {
722 assert_eq!(Some(*elt), it.idx(i));
727 fn test_random_access_cycle() {
728 let xs = [1, 2, 3, 4, 5];
729 let empty: &[isize] = &[];
730 check_randacc_iter(xs.iter().cycle().take(27), 27);
731 check_randacc_iter(empty.iter().cycle(), 0);
735 fn test_double_ended_range() {
736 assert_eq!((11..14).rev().collect::<Vec<_>>(), [13, 12, 11]);
737 for _ in (10..0).rev() {
738 panic!("unreachable");
741 assert_eq!((11..14).rev().collect::<Vec<_>>(), [13, 12, 11]);
742 for _ in (10..0).rev() {
743 panic!("unreachable");
749 assert_eq!((0..5).collect::<Vec<_>>(), [0, 1, 2, 3, 4]);
750 assert_eq!((-10..-1).collect::<Vec<_>>(), [-10, -9, -8, -7, -6, -5, -4, -3, -2]);
751 assert_eq!((0..5).rev().collect::<Vec<_>>(), [4, 3, 2, 1, 0]);
752 assert_eq!((200..-5).count(), 0);
753 assert_eq!((200..-5).rev().count(), 0);
754 assert_eq!((200..200).count(), 0);
755 assert_eq!((200..200).rev().count(), 0);
757 assert_eq!((0..100).size_hint(), (100, Some(100)));
758 // this test is only meaningful when sizeof usize < sizeof u64
759 assert_eq!((usize::MAX - 1..usize::MAX).size_hint(), (1, Some(1)));
760 assert_eq!((-10..-1).size_hint(), (9, Some(9)));
761 assert_eq!((-1..-10).size_hint(), (0, Some(0)));
763 assert_eq!((-70..58i8).size_hint(), (128, Some(128)));
764 assert_eq!((-128..127i8).size_hint(), (255, Some(255)));
765 assert_eq!((-2..isize::MAX).size_hint(),
766 (isize::MAX as usize + 2, Some(isize::MAX as usize + 2)));
770 fn test_range_inclusive() {
771 assert!(range_inclusive(0, 5).collect::<Vec<isize>>() ==
772 vec![0, 1, 2, 3, 4, 5]);
773 assert!(range_inclusive(0, 5).rev().collect::<Vec<isize>>() ==
774 vec![5, 4, 3, 2, 1, 0]);
775 assert_eq!(range_inclusive(200, -5).count(), 0);
776 assert_eq!(range_inclusive(200, -5).rev().count(), 0);
777 assert_eq!(range_inclusive(200, 200).collect::<Vec<isize>>(), [200]);
778 assert_eq!(range_inclusive(200, 200).rev().collect::<Vec<isize>>(), [200]);
782 fn test_range_step() {
783 assert_eq!((0..20).step_by(5).collect::<Vec<isize>>(), [0, 5, 10, 15]);
784 assert_eq!((20..0).step_by(-5).collect::<Vec<isize>>(), [20, 15, 10, 5]);
785 assert_eq!((20..0).step_by(-6).collect::<Vec<isize>>(), [20, 14, 8, 2]);
786 assert_eq!((200..255).step_by(50).collect::<Vec<u8>>(), [200, 250]);
787 assert_eq!((200..-5).step_by(1).collect::<Vec<isize>>(), []);
788 assert_eq!((200..200).step_by(1).collect::<Vec<isize>>(), []);
793 let mut ys = [1, 2, 3, 4, 5];
794 ys.iter_mut().reverse_in_place();
795 assert!(ys == [5, 4, 3, 2, 1]);
799 fn test_peekable_is_empty() {
801 let mut it = a.iter().peekable();
802 assert!( !it.is_empty() );
804 assert!( it.is_empty() );
809 let v: [isize; 0] = [];
810 assert_eq!(v.iter().min_max(), NoElements);
813 assert!(v.iter().min_max() == OneElement(&1));
815 let v = [1, 2, 3, 4, 5];
816 assert!(v.iter().min_max() == MinMax(&1, &5));
818 let v = [1, 2, 3, 4, 5, 6];
819 assert!(v.iter().min_max() == MinMax(&1, &6));
821 let v = [1, 1, 1, 1];
822 assert!(v.iter().min_max() == MinMax(&1, &1));
826 fn test_min_max_result() {
827 let r: MinMaxResult<isize> = NoElements;
828 assert_eq!(r.into_option(), None);
830 let r = OneElement(1);
831 assert_eq!(r.into_option(), Some((1,1)));
834 assert_eq!(r.into_option(), Some((1,2)));
839 let mut it = iterate(1, |x| x * 2);
840 assert_eq!(it.next(), Some(1));
841 assert_eq!(it.next(), Some(2));
842 assert_eq!(it.next(), Some(4));
843 assert_eq!(it.next(), Some(8));
848 let mut it = repeat(42);
849 assert_eq!(it.next(), Some(42));
850 assert_eq!(it.next(), Some(42));
851 assert_eq!(it.next(), Some(42));
857 assert_eq!(it.len(), 3);
858 assert_eq!(it.next(), Some(0));
859 assert_eq!(it.len(), 2);
860 assert_eq!(it.next(), Some(1));
861 assert_eq!(it.len(), 1);
862 assert_eq!(it.next(), Some(2));
863 assert_eq!(it.len(), 0);
864 assert_eq!(it.next(), None);
865 assert_eq!(it.len(), 0);
866 assert_eq!(it.next(), None);
867 assert_eq!(it.len(), 0);
868 assert_eq!(it.next(), None);
869 assert_eq!(it.len(), 0);
873 fn bench_rposition(b: &mut Bencher) {
874 let it: Vec<usize> = (0..300).collect();
876 it.iter().rposition(|&x| x <= 150);
881 fn bench_skip_while(b: &mut Bencher) {
885 it.skip_while(|&x| { sum += x; sum < 4000 }).all(|_| true);
890 fn bench_multiple_take(b: &mut Bencher) {
891 let mut it = (0..42).cycle();
893 let n = it.next().unwrap();
895 it.clone().take(it.next().unwrap()).all(|_| true);
900 fn scatter(x: i32) -> i32 { (x * 31) % 127 }
903 fn bench_max_by(b: &mut Bencher) {
906 it.max_by(|&x| scatter(x))
910 // http://www.reddit.com/r/rust/comments/31syce/using_iterators_to_find_the_index_of_the_min_or/
912 fn bench_max_by2(b: &mut Bencher) {
913 fn max_index_iter(array: &[i32]) -> usize {
914 array.iter().enumerate().max_by(|&(_, item)| item).unwrap().0
917 let mut data = vec![0i32; 1638];
920 b.iter(|| max_index_iter(&data));
924 fn bench_max(b: &mut Bencher) {
927 it.map(scatter).max()