1 // Copyright 2012-2015 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 and is thus
14 //! efficiently usable as a double-ended queue.
16 // DList is constructed like a singly-linked list over the field `next`.
17 // including the last link being None; each Node owns its `next` field.
19 // Backlinks over DList::prev are raw pointers that form a full chain in
20 // the reverse direction.
22 #![stable(feature = "rust1", since = "1.0.0")]
26 use alloc::boxed::Box;
27 use core::cmp::Ordering;
28 use core::default::Default;
30 use core::hash::{Writer, Hasher, Hash};
31 use core::iter::{self, FromIterator, IntoIterator};
35 /// A doubly-linked list.
36 #[stable(feature = "rust1", since = "1.0.0")]
40 list_tail: Rawlink<Node<T>>,
43 type Link<T> = Option<Box<Node<T>>>;
49 impl<T> Copy for Rawlink<T> {}
50 unsafe impl<T:'static+Send> Send for Rawlink<T> {}
51 unsafe impl<T:Send+Sync> Sync for Rawlink<T> {}
55 prev: Rawlink<Node<T>>,
59 /// An iterator over references to the items of a `DList`.
60 #[stable(feature = "rust1", since = "1.0.0")]
61 pub struct Iter<'a, T:'a> {
63 tail: Rawlink<Node<T>>,
67 // FIXME #19839: deriving is too aggressive on the bounds (T doesn't need to be Clone).
68 #[stable(feature = "rust1", since = "1.0.0")]
69 impl<'a, T> Clone for Iter<'a, T> {
70 fn clone(&self) -> Iter<'a, T> {
72 head: self.head.clone(),
79 /// An iterator over mutable references to the items of a `DList`.
80 #[stable(feature = "rust1", since = "1.0.0")]
81 pub struct IterMut<'a, T:'a> {
82 list: &'a mut DList<T>,
83 head: Rawlink<Node<T>>,
84 tail: Rawlink<Node<T>>,
88 /// An iterator over mutable references to the items of a `DList`.
90 #[stable(feature = "rust1", since = "1.0.0")]
91 pub struct IntoIter<T> {
95 /// Rawlink is a type like Option<T> but for holding a raw pointer
97 /// Like Option::None for Rawlink
98 fn none() -> Rawlink<T> {
99 Rawlink{p: ptr::null_mut()}
102 /// Like Option::Some for Rawlink
103 fn some(n: &mut T) -> Rawlink<T> {
107 /// Convert the `Rawlink` into an Option value
108 fn resolve_immut<'a>(&self) -> Option<&'a T> {
110 mem::transmute(self.p.as_ref())
114 /// Convert the `Rawlink` into an Option value
115 fn resolve<'a>(&mut self) -> Option<&'a mut T> {
116 if self.p.is_null() {
119 Some(unsafe { mem::transmute(self.p) })
123 /// Return the `Rawlink` and replace with `Rawlink::none()`
124 fn take(&mut self) -> Rawlink<T> {
125 mem::replace(self, Rawlink::none())
129 impl<T> Clone for Rawlink<T> {
131 fn clone(&self) -> Rawlink<T> {
137 fn new(v: T) -> Node<T> {
138 Node{value: v, next: None, prev: Rawlink::none()}
142 /// Set the .prev field on `next`, then return `Some(next)`
143 fn link_with_prev<T>(mut next: Box<Node<T>>, prev: Rawlink<Node<T>>)
151 /// Add a Node first in the list
153 fn push_front_node(&mut self, mut new_head: Box<Node<T>>) {
154 match self.list_head {
156 self.list_tail = Rawlink::some(&mut *new_head);
157 self.list_head = link_with_prev(new_head, Rawlink::none());
159 Some(ref mut head) => {
160 new_head.prev = Rawlink::none();
161 head.prev = Rawlink::some(&mut *new_head);
162 mem::swap(head, &mut new_head);
163 head.next = Some(new_head);
169 /// Remove the first Node and return it, or None if the list is empty
171 fn pop_front_node(&mut self) -> Option<Box<Node<T>>> {
172 self.list_head.take().map(|mut front_node| {
174 match front_node.next.take() {
175 Some(node) => self.list_head = link_with_prev(node, Rawlink::none()),
176 None => self.list_tail = Rawlink::none()
182 /// Add a Node last in the list
184 fn push_back_node(&mut self, mut new_tail: Box<Node<T>>) {
185 match self.list_tail.resolve() {
186 None => return self.push_front_node(new_tail),
188 self.list_tail = Rawlink::some(&mut *new_tail);
189 tail.next = link_with_prev(new_tail, Rawlink::some(tail));
195 /// Remove the last Node and return it, or None if the list is empty
197 fn pop_back_node(&mut self) -> Option<Box<Node<T>>> {
198 self.list_tail.resolve().map_or(None, |tail| {
200 self.list_tail = tail.prev;
201 match tail.prev.resolve() {
202 None => self.list_head.take(),
203 Some(tail_prev) => tail_prev.next.take()
209 #[stable(feature = "rust1", since = "1.0.0")]
210 impl<T> Default for DList<T> {
212 #[stable(feature = "rust1", since = "1.0.0")]
213 fn default() -> DList<T> { DList::new() }
217 /// Creates an empty `DList`.
219 #[stable(feature = "rust1", since = "1.0.0")]
220 pub fn new() -> DList<T> {
221 DList{list_head: None, list_tail: Rawlink::none(), length: 0}
224 /// Moves all elements from `other` to the end of the list.
226 /// This reuses all the nodes from `other` and moves them into `self`. After
227 /// this operation, `other` becomes empty.
229 /// This operation should compute in O(1) time and O(1) memory.
234 /// use std::collections::DList;
236 /// let mut a = DList::new();
237 /// let mut b = DList::new();
243 /// a.append(&mut b);
245 /// for e in a.iter() {
246 /// println!("{}", e); // prints 1, then 2, then 3, then 4
248 /// println!("{}", b.len()); // prints 0
250 pub fn append(&mut self, other: &mut DList<T>) {
251 match self.list_tail.resolve() {
253 self.length = other.length;
254 self.list_head = other.list_head.take();
255 self.list_tail = other.list_tail.take();
258 // Carefully empty `other`.
259 let o_tail = other.list_tail.take();
260 let o_length = other.length;
261 match other.list_head.take() {
264 tail.next = link_with_prev(node, self.list_tail);
265 self.list_tail = o_tail;
266 self.length += o_length;
274 /// Provides a forward iterator.
276 #[stable(feature = "rust1", since = "1.0.0")]
277 pub fn iter(&self) -> Iter<T> {
278 Iter{nelem: self.len(), head: &self.list_head, tail: self.list_tail}
281 /// Provides a forward iterator with mutable references.
283 #[stable(feature = "rust1", since = "1.0.0")]
284 pub fn iter_mut(&mut self) -> IterMut<T> {
285 let head_raw = match self.list_head {
286 Some(ref mut h) => Rawlink::some(&mut **h),
287 None => Rawlink::none(),
292 tail: self.list_tail,
297 /// Consumes the list into an iterator yielding elements by value.
299 #[stable(feature = "rust1", since = "1.0.0")]
300 pub fn into_iter(self) -> IntoIter<T> {
304 /// Returns `true` if the `DList` is empty.
306 /// This operation should compute in O(1) time.
311 /// use std::collections::DList;
313 /// let mut dl = DList::new();
314 /// assert!(dl.is_empty());
316 /// dl.push_front("foo");
317 /// assert!(!dl.is_empty());
320 #[stable(feature = "rust1", since = "1.0.0")]
321 pub fn is_empty(&self) -> bool {
322 self.list_head.is_none()
325 /// Returns the length of the `DList`.
327 /// This operation should compute in O(1) time.
332 /// use std::collections::DList;
334 /// let mut dl = DList::new();
336 /// dl.push_front(2);
337 /// assert_eq!(dl.len(), 1);
339 /// dl.push_front(1);
340 /// assert_eq!(dl.len(), 2);
343 /// assert_eq!(dl.len(), 3);
347 #[stable(feature = "rust1", since = "1.0.0")]
348 pub fn len(&self) -> usize {
352 /// Removes all elements from the `DList`.
354 /// This operation should compute in O(n) time.
359 /// use std::collections::DList;
361 /// let mut dl = DList::new();
363 /// dl.push_front(2);
364 /// dl.push_front(1);
365 /// assert_eq!(dl.len(), 2);
366 /// assert_eq!(dl.front(), Some(&1));
369 /// assert_eq!(dl.len(), 0);
370 /// assert_eq!(dl.front(), None);
374 #[stable(feature = "rust1", since = "1.0.0")]
375 pub fn clear(&mut self) {
379 /// Provides a reference to the front element, or `None` if the list is
385 /// use std::collections::DList;
387 /// let mut dl = DList::new();
388 /// assert_eq!(dl.front(), None);
390 /// dl.push_front(1);
391 /// assert_eq!(dl.front(), Some(&1));
395 #[stable(feature = "rust1", since = "1.0.0")]
396 pub fn front(&self) -> Option<&T> {
397 self.list_head.as_ref().map(|head| &head.value)
400 /// Provides a mutable reference to the front element, or `None` if the list
406 /// use std::collections::DList;
408 /// let mut dl = DList::new();
409 /// assert_eq!(dl.front(), None);
411 /// dl.push_front(1);
412 /// assert_eq!(dl.front(), Some(&1));
414 /// match dl.front_mut() {
416 /// Some(x) => *x = 5,
418 /// assert_eq!(dl.front(), Some(&5));
422 #[stable(feature = "rust1", since = "1.0.0")]
423 pub fn front_mut(&mut self) -> Option<&mut T> {
424 self.list_head.as_mut().map(|head| &mut head.value)
427 /// Provides a reference to the back element, or `None` if the list is
433 /// use std::collections::DList;
435 /// let mut dl = DList::new();
436 /// assert_eq!(dl.back(), None);
439 /// assert_eq!(dl.back(), Some(&1));
443 #[stable(feature = "rust1", since = "1.0.0")]
444 pub fn back(&self) -> Option<&T> {
445 self.list_tail.resolve_immut().as_ref().map(|tail| &tail.value)
448 /// Provides a mutable reference to the back element, or `None` if the list
454 /// use std::collections::DList;
456 /// let mut dl = DList::new();
457 /// assert_eq!(dl.back(), None);
460 /// assert_eq!(dl.back(), Some(&1));
462 /// match dl.back_mut() {
464 /// Some(x) => *x = 5,
466 /// assert_eq!(dl.back(), Some(&5));
470 #[stable(feature = "rust1", since = "1.0.0")]
471 pub fn back_mut(&mut self) -> Option<&mut T> {
472 self.list_tail.resolve().map(|tail| &mut tail.value)
475 /// Adds an element first in the list.
477 /// This operation should compute in O(1) time.
482 /// use std::collections::DList;
484 /// let mut dl = DList::new();
486 /// dl.push_front(2);
487 /// assert_eq!(dl.front().unwrap(), &2);
489 /// dl.push_front(1);
490 /// assert_eq!(dl.front().unwrap(), &1);
493 #[stable(feature = "rust1", since = "1.0.0")]
494 pub fn push_front(&mut self, elt: T) {
495 self.push_front_node(box Node::new(elt))
498 /// Removes the first element and returns it, or `None` if the list is
501 /// This operation should compute in O(1) time.
506 /// use std::collections::DList;
508 /// let mut d = DList::new();
509 /// assert_eq!(d.pop_front(), None);
513 /// assert_eq!(d.pop_front(), Some(3));
514 /// assert_eq!(d.pop_front(), Some(1));
515 /// assert_eq!(d.pop_front(), None);
519 #[stable(feature = "rust1", since = "1.0.0")]
520 pub fn pop_front(&mut self) -> Option<T> {
521 self.pop_front_node().map(|box Node{value, ..}| value)
524 /// Appends an element to the back of a list
529 /// use std::collections::DList;
531 /// let mut d = DList::new();
534 /// assert_eq!(3, *d.back().unwrap());
536 #[stable(feature = "rust1", since = "1.0.0")]
537 pub fn push_back(&mut self, elt: T) {
538 self.push_back_node(box Node::new(elt))
541 /// Removes the last element from a list and returns it, or `None` if
547 /// use std::collections::DList;
549 /// let mut d = DList::new();
550 /// assert_eq!(d.pop_back(), None);
553 /// assert_eq!(d.pop_back(), Some(3));
555 #[stable(feature = "rust1", since = "1.0.0")]
556 pub fn pop_back(&mut self) -> Option<T> {
557 self.pop_back_node().map(|box Node{value, ..}| value)
560 /// Splits the list into two at the given index. Returns everything after the given index,
561 /// including the index.
565 /// Panics if `at > len`.
567 /// This operation should compute in O(n) time.
572 /// use std::collections::DList;
574 /// let mut d = DList::new();
580 /// let mut splitted = d.split_off(2);
582 /// assert_eq!(splitted.pop_front(), Some(1));
583 /// assert_eq!(splitted.pop_front(), None);
585 #[stable(feature = "rust1", since = "1.0.0")]
586 pub fn split_off(&mut self, at: usize) -> DList<T> {
587 let len = self.len();
588 assert!(at <= len, "Cannot split off at a nonexistent index");
590 return mem::replace(self, DList::new());
591 } else if at == len {
595 // Below, we iterate towards the `i-1`th node, either from the start or the end,
596 // depending on which would be faster.
597 let mut split_node = if at - 1 <= len - 1 - (at - 1) {
598 let mut iter = self.iter_mut();
599 // instead of skipping using .skip() (which creates a new struct),
600 // we skip manually so we can access the head field without
601 // depending on implementation details of Skip
607 // better off starting from the end
608 let mut iter = self.iter_mut();
609 for _ in 0..len - 1 - (at - 1) {
615 let mut splitted_list = DList {
617 list_tail: self.list_tail,
621 mem::swap(&mut split_node.resolve().unwrap().next, &mut splitted_list.list_head);
622 self.list_tail = split_node;
630 #[stable(feature = "rust1", since = "1.0.0")]
631 impl<T> Drop for DList<T> {
633 // Dissolve the dlist in backwards direction
634 // Just dropping the list_head can lead to stack exhaustion
635 // when length is >> 1_000_000
636 let mut tail = self.list_tail;
638 match tail.resolve() {
641 prev.next.take(); // release Box<Node<T>>
647 self.list_head = None;
648 self.list_tail = Rawlink::none();
652 #[stable(feature = "rust1", since = "1.0.0")]
653 impl<'a, A> Iterator for Iter<'a, A> {
657 fn next(&mut self) -> Option<&'a A> {
661 self.head.as_ref().map(|head| {
663 self.head = &head.next;
669 fn size_hint(&self) -> (usize, Option<usize>) {
670 (self.nelem, Some(self.nelem))
674 #[stable(feature = "rust1", since = "1.0.0")]
675 impl<'a, A> DoubleEndedIterator for Iter<'a, A> {
677 fn next_back(&mut self) -> Option<&'a A> {
681 self.tail.resolve_immut().as_ref().map(|prev| {
683 self.tail = prev.prev;
689 #[stable(feature = "rust1", since = "1.0.0")]
690 impl<'a, A> ExactSizeIterator for Iter<'a, A> {}
692 #[stable(feature = "rust1", since = "1.0.0")]
693 impl<'a, A> Iterator for IterMut<'a, A> {
694 type Item = &'a mut A;
696 fn next(&mut self) -> Option<&'a mut A> {
700 self.head.resolve().map(|next| {
702 self.head = match next.next {
703 Some(ref mut node) => Rawlink::some(&mut **node),
704 None => Rawlink::none(),
711 fn size_hint(&self) -> (usize, Option<usize>) {
712 (self.nelem, Some(self.nelem))
716 #[stable(feature = "rust1", since = "1.0.0")]
717 impl<'a, A> DoubleEndedIterator for IterMut<'a, A> {
719 fn next_back(&mut self) -> Option<&'a mut A> {
723 self.tail.resolve().map(|prev| {
725 self.tail = prev.prev;
731 #[stable(feature = "rust1", since = "1.0.0")]
732 impl<'a, A> ExactSizeIterator for IterMut<'a, A> {}
734 // private methods for IterMut
735 impl<'a, A> IterMut<'a, A> {
736 fn insert_next_node(&mut self, mut ins_node: Box<Node<A>>) {
737 // Insert before `self.head` so that it is between the
738 // previously yielded element and self.head.
740 // The inserted node will not appear in further iteration.
741 match self.head.resolve() {
742 None => { self.list.push_back_node(ins_node); }
744 let prev_node = match node.prev.resolve() {
745 None => return self.list.push_front_node(ins_node),
748 let node_own = prev_node.next.take().unwrap();
749 ins_node.next = link_with_prev(node_own, Rawlink::some(&mut *ins_node));
750 prev_node.next = link_with_prev(ins_node, Rawlink::some(prev_node));
751 self.list.length += 1;
757 impl<'a, A> IterMut<'a, A> {
758 /// Inserts `elt` just after the element most recently returned by `.next()`.
759 /// The inserted element does not appear in the iteration.
764 /// use std::collections::DList;
766 /// let mut list: DList<_> = vec![1, 3, 4].into_iter().collect();
769 /// let mut it = list.iter_mut();
770 /// assert_eq!(it.next().unwrap(), &1);
771 /// // insert `2` after `1`
772 /// it.insert_next(2);
775 /// let vec: Vec<_> = list.into_iter().collect();
776 /// assert_eq!(vec, vec![1, 2, 3, 4]);
780 #[unstable(feature = "collections",
781 reason = "this is probably better handled by a cursor type -- we'll see")]
782 pub fn insert_next(&mut self, elt: A) {
783 self.insert_next_node(box Node::new(elt))
786 /// Provides a reference to the next element, without changing the iterator.
791 /// use std::collections::DList;
793 /// let mut list: DList<_> = vec![1, 2, 3].into_iter().collect();
795 /// let mut it = list.iter_mut();
796 /// assert_eq!(it.next().unwrap(), &1);
797 /// assert_eq!(it.peek_next().unwrap(), &2);
798 /// // We just peeked at 2, so it was not consumed from the iterator.
799 /// assert_eq!(it.next().unwrap(), &2);
802 #[unstable(feature = "collections",
803 reason = "this is probably better handled by a cursor type -- we'll see")]
804 pub fn peek_next(&mut self) -> Option<&mut A> {
808 self.head.resolve().map(|head| &mut head.value)
812 #[stable(feature = "rust1", since = "1.0.0")]
813 impl<A> Iterator for IntoIter<A> {
817 fn next(&mut self) -> Option<A> { self.list.pop_front() }
820 fn size_hint(&self) -> (usize, Option<usize>) {
821 (self.list.length, Some(self.list.length))
825 #[stable(feature = "rust1", since = "1.0.0")]
826 impl<A> DoubleEndedIterator for IntoIter<A> {
828 fn next_back(&mut self) -> Option<A> { self.list.pop_back() }
831 #[stable(feature = "rust1", since = "1.0.0")]
832 impl<A> FromIterator<A> for DList<A> {
833 fn from_iter<T: Iterator<Item=A>>(iterator: T) -> DList<A> {
834 let mut ret = DList::new();
835 ret.extend(iterator);
840 #[stable(feature = "rust1", since = "1.0.0")]
841 impl<T> IntoIterator for DList<T> {
843 type IntoIter = IntoIter<T>;
845 fn into_iter(self) -> IntoIter<T> {
850 #[stable(feature = "rust1", since = "1.0.0")]
851 impl<'a, T> IntoIterator for &'a DList<T> {
853 type IntoIter = Iter<'a, T>;
855 fn into_iter(self) -> Iter<'a, T> {
860 impl<'a, T> IntoIterator for &'a mut DList<T> {
861 type Item = &'a mut T;
862 type IntoIter = IterMut<'a, T>;
864 fn into_iter(mut self) -> IterMut<'a, T> {
869 #[stable(feature = "rust1", since = "1.0.0")]
870 impl<A> Extend<A> for DList<A> {
871 fn extend<T: Iterator<Item=A>>(&mut self, iterator: T) {
872 for elt in iterator { self.push_back(elt); }
876 #[stable(feature = "rust1", since = "1.0.0")]
877 impl<A: PartialEq> PartialEq for DList<A> {
878 fn eq(&self, other: &DList<A>) -> bool {
879 self.len() == other.len() &&
880 iter::order::eq(self.iter(), other.iter())
883 fn ne(&self, other: &DList<A>) -> bool {
884 self.len() != other.len() ||
885 iter::order::ne(self.iter(), other.iter())
889 #[stable(feature = "rust1", since = "1.0.0")]
890 impl<A: Eq> Eq for DList<A> {}
892 #[stable(feature = "rust1", since = "1.0.0")]
893 impl<A: PartialOrd> PartialOrd for DList<A> {
894 fn partial_cmp(&self, other: &DList<A>) -> Option<Ordering> {
895 iter::order::partial_cmp(self.iter(), other.iter())
899 #[stable(feature = "rust1", since = "1.0.0")]
900 impl<A: Ord> Ord for DList<A> {
902 fn cmp(&self, other: &DList<A>) -> Ordering {
903 iter::order::cmp(self.iter(), other.iter())
907 #[stable(feature = "rust1", since = "1.0.0")]
908 impl<A: Clone> Clone for DList<A> {
909 fn clone(&self) -> DList<A> {
910 self.iter().map(|x| x.clone()).collect()
914 #[stable(feature = "rust1", since = "1.0.0")]
915 impl<A: fmt::Debug> fmt::Debug for DList<A> {
916 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
917 try!(write!(f, "DList ["));
919 for (i, e) in self.iter().enumerate() {
920 if i != 0 { try!(write!(f, ", ")); }
921 try!(write!(f, "{:?}", *e));
928 #[stable(feature = "rust1", since = "1.0.0")]
929 impl<S: Writer + Hasher, A: Hash<S>> Hash<S> for DList<A> {
930 fn hash(&self, state: &mut S) {
931 self.len().hash(state);
942 use std::hash::{self, SipHasher};
947 use super::{DList, Node};
949 pub fn check_links<T>(list: &DList<T>) {
951 let mut last_ptr: Option<&Node<T>> = None;
952 let mut node_ptr: &Node<T>;
953 match list.list_head {
954 None => { assert_eq!(0, list.length); return }
955 Some(ref node) => node_ptr = &**node,
958 match (last_ptr, node_ptr.prev.resolve_immut()) {
960 (None , _ ) => panic!("prev link for list_head"),
961 (Some(p), Some(pptr)) => {
962 assert_eq!(p as *const Node<T>, pptr as *const Node<T>);
964 _ => panic!("prev link is none, not good"),
966 match node_ptr.next {
968 last_ptr = Some(node_ptr);
978 assert_eq!(len, list.length);
983 let mut m = DList::new();
984 assert_eq!(m.pop_front(), None);
985 assert_eq!(m.pop_back(), None);
986 assert_eq!(m.pop_front(), None);
988 assert_eq!(m.pop_front(), Some(box 1));
991 assert_eq!(m.len(), 2);
992 assert_eq!(m.pop_front(), Some(box 2));
993 assert_eq!(m.pop_front(), Some(box 3));
994 assert_eq!(m.len(), 0);
995 assert_eq!(m.pop_front(), None);
1000 assert_eq!(m.pop_front(), Some(box 1));
1002 let mut n = DList::new();
1006 assert_eq!(n.front().unwrap(), &3);
1007 let x = n.front_mut().unwrap();
1012 assert_eq!(n.back().unwrap(), &2);
1013 let y = n.back_mut().unwrap();
1017 assert_eq!(n.pop_front(), Some(0));
1018 assert_eq!(n.pop_front(), Some(1));
1022 fn generate_test() -> DList<i32> {
1023 list_from(&[0,1,2,3,4,5,6])
1027 fn list_from<T: Clone>(v: &[T]) -> DList<T> {
1028 v.iter().map(|x| (*x).clone()).collect()
1035 let mut m = DList::<i32>::new();
1036 let mut n = DList::new();
1039 assert_eq!(m.len(), 0);
1040 assert_eq!(n.len(), 0);
1042 // Non-empty to empty
1044 let mut m = DList::new();
1045 let mut n = DList::new();
1049 assert_eq!(m.len(), 1);
1050 assert_eq!(m.pop_back(), Some(2));
1051 assert_eq!(n.len(), 0);
1054 // Empty to non-empty
1056 let mut m = DList::new();
1057 let mut n = DList::new();
1061 assert_eq!(m.len(), 1);
1062 assert_eq!(m.pop_back(), Some(2));
1066 // Non-empty to non-empty
1067 let v = vec![1,2,3,4,5];
1068 let u = vec![9,8,1,2,3,4,5];
1069 let mut m = list_from(&v);
1070 let mut n = list_from(&u);
1075 assert_eq!(sum.len(), m.len());
1077 assert_eq!(m.pop_front(), Some(elt))
1079 assert_eq!(n.len(), 0);
1080 // let's make sure it's working properly, since we
1081 // did some direct changes to private members
1083 assert_eq!(n.len(), 1);
1084 assert_eq!(n.pop_front(), Some(3));
1089 fn test_split_off() {
1092 let mut m = DList::new();
1095 let p = m.split_off(0);
1096 assert_eq!(m.len(), 0);
1097 assert_eq!(p.len(), 1);
1098 assert_eq!(p.back(), Some(&1));
1099 assert_eq!(p.front(), Some(&1));
1102 // not singleton, forwards
1104 let u = vec![1,2,3,4,5];
1105 let mut m = list_from(&u);
1106 let mut n = m.split_off(2);
1107 assert_eq!(m.len(), 2);
1108 assert_eq!(n.len(), 3);
1110 assert_eq!(m.pop_front(), Some(elt));
1113 assert_eq!(n.pop_front(), Some(elt));
1116 // not singleton, backwards
1118 let u = vec![1,2,3,4,5];
1119 let mut m = list_from(&u);
1120 let mut n = m.split_off(4);
1121 assert_eq!(m.len(), 4);
1122 assert_eq!(n.len(), 1);
1124 assert_eq!(m.pop_front(), Some(elt));
1127 assert_eq!(n.pop_front(), Some(elt));
1131 // no-op on the last index
1133 let mut m = DList::new();
1136 let p = m.split_off(1);
1137 assert_eq!(m.len(), 1);
1138 assert_eq!(p.len(), 0);
1139 assert_eq!(m.back(), Some(&1));
1140 assert_eq!(m.front(), Some(&1));
1146 fn test_iterator() {
1147 let m = generate_test();
1148 for (i, elt) in m.iter().enumerate() {
1149 assert_eq!(i as i32, *elt);
1151 let mut n = DList::new();
1152 assert_eq!(n.iter().next(), None);
1154 let mut it = n.iter();
1155 assert_eq!(it.size_hint(), (1, Some(1)));
1156 assert_eq!(it.next().unwrap(), &4);
1157 assert_eq!(it.size_hint(), (0, Some(0)));
1158 assert_eq!(it.next(), None);
1162 fn test_iterator_clone() {
1163 let mut n = DList::new();
1167 let mut it = n.iter();
1169 let mut jt = it.clone();
1170 assert_eq!(it.next(), jt.next());
1171 assert_eq!(it.next_back(), jt.next_back());
1172 assert_eq!(it.next(), jt.next());
1176 fn test_iterator_double_end() {
1177 let mut n = DList::new();
1178 assert_eq!(n.iter().next(), None);
1182 let mut it = n.iter();
1183 assert_eq!(it.size_hint(), (3, Some(3)));
1184 assert_eq!(it.next().unwrap(), &6);
1185 assert_eq!(it.size_hint(), (2, Some(2)));
1186 assert_eq!(it.next_back().unwrap(), &4);
1187 assert_eq!(it.size_hint(), (1, Some(1)));
1188 assert_eq!(it.next_back().unwrap(), &5);
1189 assert_eq!(it.next_back(), None);
1190 assert_eq!(it.next(), None);
1194 fn test_rev_iter() {
1195 let m = generate_test();
1196 for (i, elt) in m.iter().rev().enumerate() {
1197 assert_eq!((6 - i) as i32, *elt);
1199 let mut n = DList::new();
1200 assert_eq!(n.iter().rev().next(), None);
1202 let mut it = n.iter().rev();
1203 assert_eq!(it.size_hint(), (1, Some(1)));
1204 assert_eq!(it.next().unwrap(), &4);
1205 assert_eq!(it.size_hint(), (0, Some(0)));
1206 assert_eq!(it.next(), None);
1210 fn test_mut_iter() {
1211 let mut m = generate_test();
1212 let mut len = m.len();
1213 for (i, elt) in m.iter_mut().enumerate() {
1214 assert_eq!(i as i32, *elt);
1218 let mut n = DList::new();
1219 assert!(n.iter_mut().next().is_none());
1222 let mut it = n.iter_mut();
1223 assert_eq!(it.size_hint(), (2, Some(2)));
1224 assert!(it.next().is_some());
1225 assert!(it.next().is_some());
1226 assert_eq!(it.size_hint(), (0, Some(0)));
1227 assert!(it.next().is_none());
1231 fn test_iterator_mut_double_end() {
1232 let mut n = DList::new();
1233 assert!(n.iter_mut().next_back().is_none());
1237 let mut it = n.iter_mut();
1238 assert_eq!(it.size_hint(), (3, Some(3)));
1239 assert_eq!(*it.next().unwrap(), 6);
1240 assert_eq!(it.size_hint(), (2, Some(2)));
1241 assert_eq!(*it.next_back().unwrap(), 4);
1242 assert_eq!(it.size_hint(), (1, Some(1)));
1243 assert_eq!(*it.next_back().unwrap(), 5);
1244 assert!(it.next_back().is_none());
1245 assert!(it.next().is_none());
1249 fn test_insert_prev() {
1250 let mut m = list_from(&[0,2,4,6,8]);
1253 let mut it = m.iter_mut();
1259 it.insert_next(*elt + 1);
1260 match it.peek_next() {
1261 Some(x) => assert_eq!(*x, *elt + 2),
1262 None => assert_eq!(8, *elt),
1271 assert_eq!(m.len(), 3 + len * 2);
1272 assert_eq!(m.into_iter().collect::<Vec<_>>(), vec![-2,0,1,2,3,4,5,6,7,8,9,0,1]);
1276 fn test_mut_rev_iter() {
1277 let mut m = generate_test();
1278 for (i, elt) in m.iter_mut().rev().enumerate() {
1279 assert_eq!((6 - i) as i32, *elt);
1281 let mut n = DList::new();
1282 assert!(n.iter_mut().rev().next().is_none());
1284 let mut it = n.iter_mut().rev();
1285 assert!(it.next().is_some());
1286 assert!(it.next().is_none());
1291 let n = list_from(&[1,2,3]);
1292 thread::spawn(move || {
1294 let a: &[_] = &[&1,&2,&3];
1295 assert_eq!(a, n.iter().collect::<Vec<_>>());
1296 }).join().ok().unwrap();
1301 let mut n = list_from(&[]);
1302 let mut m = list_from(&[]);
1309 let n = list_from(&[2,3,4]);
1310 let m = list_from(&[1,2,3]);
1316 let mut x = DList::new();
1317 let mut y = DList::new();
1319 assert!(hash::hash::<_, SipHasher>(&x) == hash::hash::<_, SipHasher>(&y));
1329 assert!(hash::hash::<_, SipHasher>(&x) == hash::hash::<_, SipHasher>(&y));
1334 let n = list_from(&[]);
1335 let m = list_from(&[1,2,3]);
1344 let nan = 0.0f64/0.0;
1345 let n = list_from(&[nan]);
1346 let m = list_from(&[nan]);
1352 let n = list_from(&[nan]);
1353 let one = list_from(&[1.0f64]);
1354 assert!(!(n < one));
1355 assert!(!(n > one));
1356 assert!(!(n <= one));
1357 assert!(!(n >= one));
1359 let u = list_from(&[1.0f64,2.0,nan]);
1360 let v = list_from(&[1.0f64,2.0,3.0]);
1366 let s = list_from(&[1.0f64,2.0,4.0,2.0]);
1367 let t = list_from(&[1.0f64,2.0,3.0,2.0]);
1370 assert!(!(s <= one));
1385 let list: DList<_> = (0..10).collect();
1386 assert_eq!(format!("{:?}", list), "DList [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]");
1388 let list: DList<_> = vec!["just", "one", "test", "more"].iter().cloned().collect();
1389 assert_eq!(format!("{:?}", list), "DList [\"just\", \"one\", \"test\", \"more\"]");
1393 fn fuzz_test(sz: i32) {
1394 let mut m: DList<_> = DList::new();
1398 let r: u8 = rand::random();
1424 for (a, &b) in m.into_iter().zip(v.iter()) {
1428 assert_eq!(i, v.len());
1432 fn bench_collect_into(b: &mut test::Bencher) {
1435 let _: DList<_> = v.iter().cloned().collect();
1440 fn bench_push_front(b: &mut test::Bencher) {
1441 let mut m: DList<_> = DList::new();
1448 fn bench_push_back(b: &mut test::Bencher) {
1449 let mut m: DList<_> = DList::new();
1456 fn bench_push_back_pop_back(b: &mut test::Bencher) {
1457 let mut m: DList<_> = DList::new();
1465 fn bench_push_front_pop_front(b: &mut test::Bencher) {
1466 let mut m: DList<_> = DList::new();
1474 fn bench_iter(b: &mut test::Bencher) {
1476 let m: DList<_> = v.iter().cloned().collect();
1478 assert!(m.iter().count() == 128);
1482 fn bench_iter_mut(b: &mut test::Bencher) {
1484 let mut m: DList<_> = v.iter().cloned().collect();
1486 assert!(m.iter_mut().count() == 128);
1490 fn bench_iter_rev(b: &mut test::Bencher) {
1492 let m: DList<_> = v.iter().cloned().collect();
1494 assert!(m.iter().rev().count() == 128);
1498 fn bench_iter_mut_rev(b: &mut test::Bencher) {
1500 let mut m: DList<_> = v.iter().cloned().collect();
1502 assert!(m.iter_mut().rev().count() == 128);