1 // Copyright 2012-2014 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.
11 //! A doubly-linked list with owned nodes.
13 //! The `DList` allows pushing and popping elements at either end.
15 //! `DList` implements the trait `Deque`. It should be imported with
16 //! `use collections::Deque`.
18 // DList is constructed like a singly-linked list over the field `next`.
19 // including the last link being None; each Node owns its `next` field.
21 // Backlinks over DList::prev are raw pointers that form a full chain in
22 // the reverse direction.
26 use alloc::boxed::Box;
27 use core::default::Default;
32 use std::hash::{Writer, Hash};
34 /// A doubly-linked list.
38 list_tail: Rawlink<Node<T>>,
41 type Link<T> = Option<Box<Node<T>>>;
47 impl<T> Copy for Rawlink<T> {}
51 prev: Rawlink<Node<T>>,
55 /// An iterator over references to the items of a `DList`.
56 pub struct Items<'a, T:'a> {
58 tail: Rawlink<Node<T>>,
62 // FIXME #11820: the &'a Option<> of the Link stops clone working.
63 impl<'a, T> Clone for Items<'a, T> {
64 fn clone(&self) -> Items<'a, T> { *self }
67 impl<'a,T> Copy for Items<'a,T> {}
69 /// An iterator over mutable references to the items of a `DList`.
70 pub struct MutItems<'a, T:'a> {
71 list: &'a mut DList<T>,
72 head: Rawlink<Node<T>>,
73 tail: Rawlink<Node<T>>,
77 /// An iterator over mutable references to the items of a `DList`.
79 pub struct MoveItems<T> {
83 /// Rawlink is a type like Option<T> but for holding a raw pointer
85 /// Like Option::None for Rawlink
86 fn none() -> Rawlink<T> {
87 Rawlink{p: ptr::null_mut()}
90 /// Like Option::Some for Rawlink
91 fn some(n: &mut T) -> Rawlink<T> {
95 /// Convert the `Rawlink` into an Option value
96 fn resolve_immut<'a>(&self) -> Option<&'a T> {
102 /// Convert the `Rawlink` into an Option value
103 fn resolve<'a>(&mut self) -> Option<&'a mut T> {
104 if self.p.is_null() {
107 Some(unsafe { mem::transmute(self.p) })
111 /// Return the `Rawlink` and replace with `Rawlink::none()`
112 fn take(&mut self) -> Rawlink<T> {
113 mem::replace(self, Rawlink::none())
117 impl<T> Clone for Rawlink<T> {
119 fn clone(&self) -> Rawlink<T> {
125 fn new(v: T) -> Node<T> {
126 Node{value: v, next: None, prev: Rawlink::none()}
130 /// Set the .prev field on `next`, then return `Some(next)`
131 fn link_with_prev<T>(mut next: Box<Node<T>>, prev: Rawlink<Node<T>>)
139 /// Add a Node first in the list
141 fn push_front_node(&mut self, mut new_head: Box<Node<T>>) {
142 match self.list_head {
144 self.list_tail = Rawlink::some(&mut *new_head);
145 self.list_head = link_with_prev(new_head, Rawlink::none());
147 Some(ref mut head) => {
148 new_head.prev = Rawlink::none();
149 head.prev = Rawlink::some(&mut *new_head);
150 mem::swap(head, &mut new_head);
151 head.next = Some(new_head);
157 /// Remove the first Node and return it, or None if the list is empty
159 fn pop_front_node(&mut self) -> Option<Box<Node<T>>> {
160 self.list_head.take().map(|mut front_node| {
162 match front_node.next.take() {
163 Some(node) => self.list_head = link_with_prev(node, Rawlink::none()),
164 None => self.list_tail = Rawlink::none()
170 /// Add a Node last in the list
172 fn push_back_node(&mut self, mut new_tail: Box<Node<T>>) {
173 match self.list_tail.resolve() {
174 None => return self.push_front_node(new_tail),
176 self.list_tail = Rawlink::some(&mut *new_tail);
177 tail.next = link_with_prev(new_tail, Rawlink::some(tail));
183 /// Remove the last Node and return it, or None if the list is empty
185 fn pop_back_node(&mut self) -> Option<Box<Node<T>>> {
186 self.list_tail.resolve().map_or(None, |tail| {
188 self.list_tail = tail.prev;
189 match tail.prev.resolve() {
190 None => self.list_head.take(),
191 Some(tail_prev) => tail_prev.next.take()
197 impl<T> Default for DList<T> {
199 fn default() -> DList<T> { DList::new() }
203 /// Creates an empty `DList`.
205 #[unstable = "matches collection reform specification, waiting for dust to settle"]
206 pub fn new() -> DList<T> {
207 DList{list_head: None, list_tail: Rawlink::none(), length: 0}
210 /// Moves the last element to the front of the list.
212 /// If the list is empty, does nothing.
217 /// use std::collections::DList;
219 /// let mut dl = DList::new();
220 /// dl.push_back(1i);
224 /// dl.rotate_forward();
226 /// for e in dl.iter() {
227 /// println!("{}", e); // prints 3, then 1, then 2
231 pub fn rotate_forward(&mut self) {
232 self.pop_back_node().map(|tail| {
233 self.push_front_node(tail)
237 /// Moves the first element to the back of the list.
239 /// If the list is empty, does nothing.
244 /// use std::collections::DList;
246 /// let mut dl = DList::new();
247 /// dl.push_back(1i);
251 /// dl.rotate_backward();
253 /// for e in dl.iter() {
254 /// println!("{}", e); // prints 2, then 3, then 1
258 pub fn rotate_backward(&mut self) {
259 self.pop_front_node().map(|head| {
260 self.push_back_node(head)
264 /// Adds all elements from `other` to the end of the list.
266 /// This operation should compute in O(1) time.
271 /// use std::collections::DList;
273 /// let mut a = DList::new();
274 /// let mut b = DList::new();
282 /// for e in a.iter() {
283 /// println!("{}", e); // prints 1, then 2, then 3, then 4
286 pub fn append(&mut self, mut other: DList<T>) {
287 match self.list_tail.resolve() {
288 None => *self = other,
290 // Carefully empty `other`.
291 let o_tail = other.list_tail.take();
292 let o_length = other.length;
293 match other.list_head.take() {
296 tail.next = link_with_prev(node, self.list_tail);
297 self.list_tail = o_tail;
298 self.length += o_length;
305 /// Adds all elements from `other` to the beginning of the list.
307 /// This operation should compute in O(1) time.
312 /// use std::collections::DList;
314 /// let mut a = DList::new();
315 /// let mut b = DList::new();
323 /// for e in a.iter() {
324 /// println!("{}", e); // prints 3, then 4, then 1, then 2
328 pub fn prepend(&mut self, mut other: DList<T>) {
329 mem::swap(self, &mut other);
333 /// Inserts `elt` before the first `x` in the list where `f(x, elt)` is
334 /// true, or at the end.
336 /// This operation should compute in O(N) time.
341 /// use std::collections::DList;
343 /// let mut a: DList<int> = DList::new();
349 /// // insert 11 before the first odd number in the list
350 /// a.insert_when(11, |&e, _| e % 2 == 1);
352 /// for e in a.iter() {
353 /// println!("{}", e); // prints 2, then 4, then 11, then 7, then 8
356 pub fn insert_when(&mut self, elt: T, f: |&T, &T| -> bool) {
358 let mut it = self.iter_mut();
360 match it.peek_next() {
362 Some(x) => if f(x, &elt) { break }
370 /// Merges `other` into this `DList`, using the function `f`.
372 /// Iterates both `DList`s with `a` from self and `b` from `other`, and
373 /// put `a` in the result if `f(a, b)` is true, and otherwise `b`.
375 /// This operation should compute in O(max(N, M)) time.
376 pub fn merge(&mut self, mut other: DList<T>, f: |&T, &T| -> bool) {
378 let mut it = self.iter_mut();
380 let take_a = match (it.peek_next(), other.front()) {
381 (_ , None) => return,
383 (Some(ref mut x), Some(y)) => f(*x, y),
388 it.insert_next_node(other.pop_front_node().unwrap());
396 /// Provides a forward iterator.
398 #[unstable = "matches collection reform specification, waiting for dust to settle"]
399 pub fn iter<'a>(&'a self) -> Items<'a, T> {
400 Items{nelem: self.len(), head: &self.list_head, tail: self.list_tail}
403 /// Provides a forward iterator with mutable references.
405 #[unstable = "matches collection reform specification, waiting for dust to settle"]
406 pub fn iter_mut<'a>(&'a mut self) -> MutItems<'a, T> {
407 let head_raw = match self.list_head {
408 Some(ref mut h) => Rawlink::some(&mut **h),
409 None => Rawlink::none(),
414 tail: self.list_tail,
419 /// Consumes the list into an iterator yielding elements by value.
421 #[unstable = "matches collection reform specification, waiting for dust to settle"]
422 pub fn into_iter(self) -> MoveItems<T> {
423 MoveItems{list: self}
426 /// Returns `true` if the `DList` is empty.
428 /// This operation should compute in O(1) time.
430 #[unstable = "matches collection reform specification, waiting for dust to settle"]
431 pub fn is_empty(&self) -> bool {
432 self.list_head.is_none()
435 /// Returns the length of the `DList`.
437 /// This operation should compute in O(1) time.
439 #[unstable = "matches collection reform specification, waiting for dust to settle"]
440 pub fn len(&self) -> uint {
444 /// Removes all elements from the `DList`.
446 /// This operation should compute in O(n) time.
448 #[unstable = "matches collection reform specification, waiting for dust to settle"]
449 pub fn clear(&mut self) {
453 /// Provides a reference to the front element, or `None` if the list is
456 #[unstable = "matches collection reform specification, waiting for dust to settle"]
457 pub fn front(&self) -> Option<&T> {
458 self.list_head.as_ref().map(|head| &head.value)
461 /// Provides a mutable reference to the front element, or `None` if the list
464 #[unstable = "matches collection reform specification, waiting for dust to settle"]
465 pub fn front_mut(&mut self) -> Option<&mut T> {
466 self.list_head.as_mut().map(|head| &mut head.value)
469 /// Provides a reference to the back element, or `None` if the list is
472 #[unstable = "matches collection reform specification, waiting for dust to settle"]
473 pub fn back(&self) -> Option<&T> {
474 self.list_tail.resolve_immut().as_ref().map(|tail| &tail.value)
477 /// Provides a mutable reference to the back element, or `None` if the list
480 #[unstable = "matches collection reform specification, waiting for dust to settle"]
481 pub fn back_mut(&mut self) -> Option<&mut T> {
482 self.list_tail.resolve().map(|tail| &mut tail.value)
485 /// Adds an element first in the list.
487 /// This operation should compute in O(1) time.
488 #[unstable = "matches collection reform specification, waiting for dust to settle"]
489 pub fn push_front(&mut self, elt: T) {
490 self.push_front_node(box Node::new(elt))
493 /// Removes the first element and returns it, or `None` if the list is
496 /// This operation should compute in O(1) time.
497 #[unstable = "matches collection reform specification, waiting for dust to settle"]
498 pub fn pop_front(&mut self) -> Option<T> {
499 self.pop_front_node().map(|box Node{value, ..}| value)
502 /// Deprecated: Renamed to `push_back`.
503 #[deprecated = "Renamed to `push_back`"]
504 pub fn push(&mut self, elt: T) {
508 /// Appends an element to the back of a list
513 /// use std::collections::DList;
515 /// let mut d = DList::new();
518 /// assert_eq!(3, *d.back().unwrap());
520 #[unstable = "matches collection reform specification, waiting for dust to settle"]
521 pub fn push_back(&mut self, elt: T) {
522 self.push_back_node(box Node::new(elt))
525 /// Deprecated: Renamed to `pop_back`.
526 #[deprecated = "Renamed to `pop_back`"]
527 pub fn pop(&mut self) -> Option<T> {
531 /// Removes the last element from a list and returns it, or `None` if
537 /// use std::collections::DList;
539 /// let mut d = DList::new();
540 /// assert_eq!(d.pop_back(), None);
543 /// assert_eq!(d.pop_back(), Some(3));
545 #[unstable = "matches collection reform specification, waiting for dust to settle"]
546 pub fn pop_back(&mut self) -> Option<T> {
547 self.pop_back_node().map(|box Node{value, ..}| value)
551 impl<T: Ord> DList<T> {
552 /// Inserts `elt` sorted in ascending order.
554 /// This operation should compute in O(N) time.
556 pub fn insert_ordered(&mut self, elt: T) {
557 self.insert_when(elt, |a, b| a >= b)
562 impl<T> Drop for DList<T> {
564 // Dissolve the dlist in backwards direction
565 // Just dropping the list_head can lead to stack exhaustion
566 // when length is >> 1_000_000
567 let mut tail = self.list_tail;
569 match tail.resolve() {
572 prev.next.take(); // release Box<Node<T>>
578 self.list_head = None;
579 self.list_tail = Rawlink::none();
584 impl<'a, A> Iterator<&'a A> for Items<'a, A> {
586 fn next(&mut self) -> Option<&'a A> {
590 self.head.as_ref().map(|head| {
592 self.head = &head.next;
598 fn size_hint(&self) -> (uint, Option<uint>) {
599 (self.nelem, Some(self.nelem))
603 impl<'a, A> DoubleEndedIterator<&'a A> for Items<'a, A> {
605 fn next_back(&mut self) -> Option<&'a A> {
609 self.tail.resolve_immut().as_ref().map(|prev| {
611 self.tail = prev.prev;
617 impl<'a, A> ExactSizeIterator<&'a A> for Items<'a, A> {}
619 impl<'a, A> Iterator<&'a mut A> for MutItems<'a, A> {
621 fn next(&mut self) -> Option<&'a mut A> {
625 self.head.resolve().map(|next| {
627 self.head = match next.next {
628 Some(ref mut node) => Rawlink::some(&mut **node),
629 None => Rawlink::none(),
636 fn size_hint(&self) -> (uint, Option<uint>) {
637 (self.nelem, Some(self.nelem))
641 impl<'a, A> DoubleEndedIterator<&'a mut A> for MutItems<'a, A> {
643 fn next_back(&mut self) -> Option<&'a mut A> {
647 self.tail.resolve().map(|prev| {
649 self.tail = prev.prev;
655 impl<'a, A> ExactSizeIterator<&'a mut A> for MutItems<'a, A> {}
657 /// Allows mutating a `DList` while iterating.
658 pub trait ListInsertion<A> {
659 /// Inserts `elt` just after to the element most recently returned by
662 /// The inserted element does not appear in the iteration.
663 fn insert_next(&mut self, elt: A);
665 /// Provides a reference to the next element, without changing the iterator
666 fn peek_next<'a>(&'a mut self) -> Option<&'a mut A>;
669 // private methods for MutItems
670 impl<'a, A> MutItems<'a, A> {
671 fn insert_next_node(&mut self, mut ins_node: Box<Node<A>>) {
672 // Insert before `self.head` so that it is between the
673 // previously yielded element and self.head.
675 // The inserted node will not appear in further iteration.
676 match self.head.resolve() {
677 None => { self.list.push_back_node(ins_node); }
679 let prev_node = match node.prev.resolve() {
680 None => return self.list.push_front_node(ins_node),
683 let node_own = prev_node.next.take().unwrap();
684 ins_node.next = link_with_prev(node_own, Rawlink::some(&mut *ins_node));
685 prev_node.next = link_with_prev(ins_node, Rawlink::some(prev_node));
686 self.list.length += 1;
692 impl<'a, A> ListInsertion<A> for MutItems<'a, A> {
694 fn insert_next(&mut self, elt: A) {
695 self.insert_next_node(box Node::new(elt))
699 fn peek_next<'a>(&'a mut self) -> Option<&'a mut A> {
703 self.head.resolve().map(|head| &mut head.value)
707 impl<A> Iterator<A> for MoveItems<A> {
709 fn next(&mut self) -> Option<A> { self.list.pop_front() }
712 fn size_hint(&self) -> (uint, Option<uint>) {
713 (self.list.length, Some(self.list.length))
717 impl<A> DoubleEndedIterator<A> for MoveItems<A> {
719 fn next_back(&mut self) -> Option<A> { self.list.pop_back() }
722 impl<A> FromIterator<A> for DList<A> {
723 fn from_iter<T: Iterator<A>>(iterator: T) -> DList<A> {
724 let mut ret = DList::new();
725 ret.extend(iterator);
730 impl<A> Extend<A> for DList<A> {
731 fn extend<T: Iterator<A>>(&mut self, mut iterator: T) {
732 for elt in iterator { self.push_back(elt); }
736 impl<A: PartialEq> PartialEq for DList<A> {
737 fn eq(&self, other: &DList<A>) -> bool {
738 self.len() == other.len() &&
739 iter::order::eq(self.iter(), other.iter())
742 fn ne(&self, other: &DList<A>) -> bool {
743 self.len() != other.len() ||
744 iter::order::ne(self.iter(), other.iter())
748 impl<A: Eq> Eq for DList<A> {}
750 impl<A: PartialOrd> PartialOrd for DList<A> {
751 fn partial_cmp(&self, other: &DList<A>) -> Option<Ordering> {
752 iter::order::partial_cmp(self.iter(), other.iter())
756 impl<A: Ord> Ord for DList<A> {
758 fn cmp(&self, other: &DList<A>) -> Ordering {
759 iter::order::cmp(self.iter(), other.iter())
763 impl<A: Clone> Clone for DList<A> {
764 fn clone(&self) -> DList<A> {
765 self.iter().map(|x| x.clone()).collect()
769 impl<A: fmt::Show> fmt::Show for DList<A> {
770 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
771 try!(write!(f, "["));
773 for (i, e) in self.iter().enumerate() {
774 if i != 0 { try!(write!(f, ", ")); }
775 try!(write!(f, "{}", *e));
782 impl<S: Writer, A: Hash<S>> Hash<S> for DList<A> {
783 fn hash(&self, state: &mut S) {
784 self.len().hash(state);
785 for elt in self.iter() {
799 use super::{DList, Node, ListInsertion};
802 pub fn check_links<T>(list: &DList<T>) {
804 let mut last_ptr: Option<&Node<T>> = None;
805 let mut node_ptr: &Node<T>;
806 match list.list_head {
807 None => { assert_eq!(0u, list.length); return }
808 Some(ref node) => node_ptr = &**node,
811 match (last_ptr, node_ptr.prev.resolve_immut()) {
813 (None , _ ) => panic!("prev link for list_head"),
814 (Some(p), Some(pptr)) => {
815 assert_eq!(p as *const Node<T>, pptr as *const Node<T>);
817 _ => panic!("prev link is none, not good"),
819 match node_ptr.next {
821 last_ptr = Some(node_ptr);
831 assert_eq!(len, list.length);
836 let mut m: DList<Box<int>> = DList::new();
837 assert_eq!(m.pop_front(), None);
838 assert_eq!(m.pop_back(), None);
839 assert_eq!(m.pop_front(), None);
841 assert_eq!(m.pop_front(), Some(box 1));
844 assert_eq!(m.len(), 2);
845 assert_eq!(m.pop_front(), Some(box 2));
846 assert_eq!(m.pop_front(), Some(box 3));
847 assert_eq!(m.len(), 0);
848 assert_eq!(m.pop_front(), None);
853 assert_eq!(m.pop_front(), Some(box 1));
855 let mut n = DList::new();
859 assert_eq!(n.front().unwrap(), &3);
860 let x = n.front_mut().unwrap();
865 assert_eq!(n.back().unwrap(), &2);
866 let y = n.back_mut().unwrap();
870 assert_eq!(n.pop_front(), Some(0));
871 assert_eq!(n.pop_front(), Some(1));
875 fn generate_test() -> DList<int> {
876 list_from(&[0i,1,2,3,4,5,6])
880 fn list_from<T: Clone>(v: &[T]) -> DList<T> {
881 v.iter().map(|x| (*x).clone()).collect()
888 let mut m = DList::new();
889 let mut n = DList::new();
892 assert_eq!(m.len(), 1);
893 assert_eq!(m.pop_back(), Some(2));
897 let mut m = DList::new();
898 let n = DList::new();
901 assert_eq!(m.len(), 1);
902 assert_eq!(m.pop_back(), Some(2));
906 let v = vec![1i,2,3,4,5];
907 let u = vec![9i,8,1,2,3,4,5];
908 let mut m = list_from(v.as_slice());
909 m.append(list_from(u.as_slice()));
912 sum.push_all(u.as_slice());
913 assert_eq!(sum.len(), m.len());
914 for elt in sum.into_iter() {
915 assert_eq!(m.pop_front(), Some(elt))
922 let mut m = DList::new();
923 let mut n = DList::new();
926 assert_eq!(m.len(), 1);
927 assert_eq!(m.pop_back(), Some(2));
931 let v = vec![1i,2,3,4,5];
932 let mut u = vec![9i,8,1,2,3,4,5];
933 let mut m = list_from(v.as_slice());
934 m.prepend(list_from(u.as_slice()));
936 u.extend(v.iter().map(|&b| b));
937 assert_eq!(u.len(), m.len());
938 for elt in u.into_iter() {
939 assert_eq!(m.pop_front(), Some(elt))
945 let mut n: DList<int> = DList::new();
946 n.rotate_backward(); check_links(&n);
947 assert_eq!(n.len(), 0);
948 n.rotate_forward(); check_links(&n);
949 assert_eq!(n.len(), 0);
951 let v = vec![1i,2,3,4,5];
952 let mut m = list_from(v.as_slice());
953 m.rotate_backward(); check_links(&m);
954 m.rotate_forward(); check_links(&m);
955 assert_eq!(v.iter().collect::<Vec<&int>>(), m.iter().collect::<Vec<_>>());
956 m.rotate_forward(); check_links(&m);
957 m.rotate_forward(); check_links(&m);
958 m.pop_front(); check_links(&m);
959 m.rotate_forward(); check_links(&m);
960 m.rotate_backward(); check_links(&m);
961 m.push_front(9); check_links(&m);
962 m.rotate_forward(); check_links(&m);
963 assert_eq!(vec![3i,9,5,1,2], m.into_iter().collect::<Vec<_>>());
968 let m = generate_test();
969 for (i, elt) in m.iter().enumerate() {
970 assert_eq!(i as int, *elt);
972 let mut n = DList::new();
973 assert_eq!(n.iter().next(), None);
975 let mut it = n.iter();
976 assert_eq!(it.size_hint(), (1, Some(1)));
977 assert_eq!(it.next().unwrap(), &4);
978 assert_eq!(it.size_hint(), (0, Some(0)));
979 assert_eq!(it.next(), None);
983 fn test_iterator_clone() {
984 let mut n = DList::new();
988 let mut it = n.iter();
990 let mut jt = it.clone();
991 assert_eq!(it.next(), jt.next());
992 assert_eq!(it.next_back(), jt.next_back());
993 assert_eq!(it.next(), jt.next());
997 fn test_iterator_double_end() {
998 let mut n = DList::new();
999 assert_eq!(n.iter().next(), None);
1003 let mut it = n.iter();
1004 assert_eq!(it.size_hint(), (3, Some(3)));
1005 assert_eq!(it.next().unwrap(), &6);
1006 assert_eq!(it.size_hint(), (2, Some(2)));
1007 assert_eq!(it.next_back().unwrap(), &4);
1008 assert_eq!(it.size_hint(), (1, Some(1)));
1009 assert_eq!(it.next_back().unwrap(), &5);
1010 assert_eq!(it.next_back(), None);
1011 assert_eq!(it.next(), None);
1015 fn test_rev_iter() {
1016 let m = generate_test();
1017 for (i, elt) in m.iter().rev().enumerate() {
1018 assert_eq!((6 - i) as int, *elt);
1020 let mut n = DList::new();
1021 assert_eq!(n.iter().rev().next(), None);
1023 let mut it = n.iter().rev();
1024 assert_eq!(it.size_hint(), (1, Some(1)));
1025 assert_eq!(it.next().unwrap(), &4);
1026 assert_eq!(it.size_hint(), (0, Some(0)));
1027 assert_eq!(it.next(), None);
1031 fn test_mut_iter() {
1032 let mut m = generate_test();
1033 let mut len = m.len();
1034 for (i, elt) in m.iter_mut().enumerate() {
1035 assert_eq!(i as int, *elt);
1039 let mut n = DList::new();
1040 assert!(n.iter_mut().next().is_none());
1043 let mut it = n.iter_mut();
1044 assert_eq!(it.size_hint(), (2, Some(2)));
1045 assert!(it.next().is_some());
1046 assert!(it.next().is_some());
1047 assert_eq!(it.size_hint(), (0, Some(0)));
1048 assert!(it.next().is_none());
1052 fn test_iterator_mut_double_end() {
1053 let mut n = DList::new();
1054 assert!(n.iter_mut().next_back().is_none());
1058 let mut it = n.iter_mut();
1059 assert_eq!(it.size_hint(), (3, Some(3)));
1060 assert_eq!(*it.next().unwrap(), 6);
1061 assert_eq!(it.size_hint(), (2, Some(2)));
1062 assert_eq!(*it.next_back().unwrap(), 4);
1063 assert_eq!(it.size_hint(), (1, Some(1)));
1064 assert_eq!(*it.next_back().unwrap(), 5);
1065 assert!(it.next_back().is_none());
1066 assert!(it.next().is_none());
1070 fn test_insert_prev() {
1071 let mut m = list_from(&[0i,2,4,6,8]);
1074 let mut it = m.iter_mut();
1080 it.insert_next(*elt + 1);
1081 match it.peek_next() {
1082 Some(x) => assert_eq!(*x, *elt + 2),
1083 None => assert_eq!(8, *elt),
1092 assert_eq!(m.len(), 3 + len * 2);
1093 assert_eq!(m.into_iter().collect::<Vec<int>>(), vec![-2,0,1,2,3,4,5,6,7,8,9,0,1]);
1098 let mut m = list_from(&[0i, 1, 3, 5, 6, 7, 2]);
1099 let n = list_from(&[-1i, 0, 0, 7, 7, 9]);
1100 let len = m.len() + n.len();
1101 m.merge(n, |a, b| a <= b);
1102 assert_eq!(m.len(), len);
1104 let res = m.into_iter().collect::<Vec<int>>();
1105 assert_eq!(res, vec![-1, 0, 0, 0, 1, 3, 5, 6, 7, 2, 7, 7, 9]);
1109 fn test_insert_ordered() {
1110 let mut n = DList::new();
1111 n.insert_ordered(1i);
1112 assert_eq!(n.len(), 1);
1113 assert_eq!(n.pop_front(), Some(1));
1115 let mut m = DList::new();
1118 m.insert_ordered(3);
1120 assert_eq!(vec![2,3,4], m.into_iter().collect::<Vec<int>>());
1124 fn test_mut_rev_iter() {
1125 let mut m = generate_test();
1126 for (i, elt) in m.iter_mut().rev().enumerate() {
1127 assert_eq!((6-i) as int, *elt);
1129 let mut n = DList::new();
1130 assert!(n.iter_mut().rev().next().is_none());
1132 let mut it = n.iter_mut().rev();
1133 assert!(it.next().is_some());
1134 assert!(it.next().is_none());
1139 let n = list_from(&[1i,2,3]);
1142 let a: &[_] = &[&1,&2,&3];
1143 assert_eq!(a, n.iter().collect::<Vec<&int>>());
1149 let mut n: DList<u8> = list_from(&[]);
1150 let mut m = list_from(&[]);
1157 let n = list_from(&[2i,3,4]);
1158 let m = list_from(&[1i,2,3]);
1164 let mut x = DList::new();
1165 let mut y = DList::new();
1167 assert!(hash::hash(&x) == hash::hash(&y));
1177 assert!(hash::hash(&x) == hash::hash(&y));
1182 let n: DList<int> = list_from(&[]);
1183 let m = list_from(&[1i,2,3]);
1192 let nan = 0.0f64/0.0;
1193 let n = list_from(&[nan]);
1194 let m = list_from(&[nan]);
1200 let n = list_from(&[nan]);
1201 let one = list_from(&[1.0f64]);
1202 assert!(!(n < one));
1203 assert!(!(n > one));
1204 assert!(!(n <= one));
1205 assert!(!(n >= one));
1207 let u = list_from(&[1.0f64,2.0,nan]);
1208 let v = list_from(&[1.0f64,2.0,3.0]);
1214 let s = list_from(&[1.0f64,2.0,4.0,2.0]);
1215 let t = list_from(&[1.0f64,2.0,3.0,2.0]);
1218 assert!(!(s <= one));
1224 for _ in range(0u, 25) {
1233 let list: DList<int> = range(0i, 10).collect();
1234 assert!(list.to_string() == "[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]");
1236 let list: DList<&str> = vec!["just", "one", "test", "more"].iter()
1239 assert!(list.to_string() == "[just, one, test, more]");
1243 fn fuzz_test(sz: int) {
1244 let mut m: DList<int> = DList::new();
1246 for i in range(0, sz) {
1248 let r: u8 = rand::random();
1272 for (a, &b) in m.into_iter().zip(v.iter()) {
1276 assert_eq!(i, v.len());
1280 fn bench_collect_into(b: &mut test::Bencher) {
1281 let v = &[0i, ..64];
1283 let _: DList<int> = v.iter().map(|x| *x).collect();
1288 fn bench_push_front(b: &mut test::Bencher) {
1289 let mut m: DList<int> = DList::new();
1296 fn bench_push_back(b: &mut test::Bencher) {
1297 let mut m: DList<int> = DList::new();
1304 fn bench_push_back_pop_back(b: &mut test::Bencher) {
1305 let mut m: DList<int> = DList::new();
1313 fn bench_push_front_pop_front(b: &mut test::Bencher) {
1314 let mut m: DList<int> = DList::new();
1322 fn bench_rotate_forward(b: &mut test::Bencher) {
1323 let mut m: DList<int> = DList::new();
1332 fn bench_rotate_backward(b: &mut test::Bencher) {
1333 let mut m: DList<int> = DList::new();
1337 m.rotate_backward();
1342 fn bench_iter(b: &mut test::Bencher) {
1343 let v = &[0i, ..128];
1344 let m: DList<int> = v.iter().map(|&x|x).collect();
1346 assert!(m.iter().count() == 128);
1350 fn bench_iter_mut(b: &mut test::Bencher) {
1351 let v = &[0i, ..128];
1352 let mut m: DList<int> = v.iter().map(|&x|x).collect();
1354 assert!(m.iter_mut().count() == 128);
1358 fn bench_iter_rev(b: &mut test::Bencher) {
1359 let v = &[0i, ..128];
1360 let m: DList<int> = v.iter().map(|&x|x).collect();
1362 assert!(m.iter().rev().count() == 128);
1366 fn bench_iter_mut_rev(b: &mut test::Bencher) {
1367 let v = &[0i, ..128];
1368 let mut m: DList<int> = v.iter().map(|&x|x).collect();
1370 assert!(m.iter_mut().rev().count() == 128);