LinkedList class - dart:collection library (original) (raw)
LinkedList<E extends LinkedListEntry<E>> class base
A specialized double-linked list of elements that extends LinkedListEntry.
This is not a generic data structure. It only accepts elements that _extend_the LinkedListEntry class. See the Queue implementations for generic collections that allow constant time adding and removing at the ends.
This is not a List implementation. Despite its name, this class does not implement the List interface. It does not allow constant time lookup by index.
Because the elements themselves contain the links of this linked list, each element can be in only one list at a time. To add an element to another list, it must first be removed from its current list (if any). For the same reason, the remove and contains methods are based on identity, even if the LinkedListEntry chooses to override Object.==.
In return, each element knows its own place in the linked list, as well as which list it is in. This allows constant timeLinkedListEntry.insertAfter, LinkedListEntry.insertBefore andLinkedListEntry.unlink operations when all you have is the element.
A LinkedList also allows constant time adding and removing at either end, and a constant time length getter.
Example:
final class EntryItem extends LinkedListEntry<EntryItem> {
final int id;
final String text;
EntryItem(this.id, this.text);
@override
String toString() {
return '$id : $text';
}
}
void main() {
final linkedList = LinkedList<EntryItem>();
linkedList
.addAll([EntryItem(1, 'A'), EntryItem(2, 'B'), EntryItem(3, 'C')]);
print(linkedList.first); // 1 : A
print(linkedList.last); // 3 : C
// Add new item after first item.
linkedList.first.insertAfter(EntryItem(15, 'E'));
// Add new item before last item.
linkedList.last.insertBefore(EntryItem(10, 'D'));
// Iterate items.
for (var entry in linkedList) {
print(entry);
// 1 : A
// 15 : E
// 2 : B
// 10 : D
// 3 : C
}
// Remove item using index from list.
linkedList.elementAt(2).unlink();
print(linkedList); // (1 : A, 15 : E, 10 : D, 3 : C)
// Remove first item.
linkedList.first.unlink();
print(linkedList); // (15 : E, 10 : D, 3 : C)
// Remove last item from list.
linkedList.remove(linkedList.last);
print(linkedList); // (15 : E, 10 : D)
// Remove all items.
linkedList.clear();
print(linkedList.length); // 0
print(linkedList.isEmpty); // true
}
Inheritance
Constructors
Constructs a new empty linked list.
Properties
first → E
The first element.
no setteroverride
The hash code for this object.
no setterinherited
Whether this collection has no elements.
no setteroverride
Whether this collection has at least one element.
no setterinherited
A new Iterator that allows iterating the elements of this Iterable.
no setteroverride
last → E
The last element.
no setteroverride
The number of elements in this Iterable.
no setteroverride
A representation of the runtime type of the object.
no setterinherited
single → E
Checks that this iterable has only one element, and returns that element.
no setteroverride
Methods
add(E entry)→ void
Adds entry to the end of the linked list.
addAll(Iterable<E> entries)→ void
Adds entries to the end of the linked list.
addFirst(E entry)→ void
Adds entry to the beginning of the linked list.
any(bool test(E element))→ bool
Checks whether any element of this iterable satisfies test.
inherited
A view of this iterable as an iterable of R instances.
inherited
clear()→ void
Remove all elements from this linked list.
Whether entry is a LinkedListEntry belonging to this list.
override
Returns the indexth element.
inherited
every(bool test(E element))→ bool
Checks whether every element of this iterable satisfies test.
inherited
expand<T>(Iterable<T> toElements(E element))→ Iterable<T>
Expands each element of this Iterable into zero or more elements.
inherited
firstWhere(bool test(E element), {E orElse()?})→ E
The first element that satisfies the given predicate test.
inherited
fold<T>(T initialValue, T combine(T previousValue, E element))→ T
Reduces a collection to a single value by iteratively combining each element of the collection with an existing value
inherited
followedBy(Iterable<E> other)→ Iterable<E>
Creates the lazy concatenation of this iterable and other.
inherited
forEach(void action(E entry))→ void
Call action with each entry in this linked list.
override
join([String separator = ""])→ String
Converts each element to a String and concatenates the strings.
inherited
lastWhere(bool test(E element), {E orElse()?})→ E
The last element that satisfies the given predicate test.
inherited
map<T>(T toElement(E e))→ Iterable<T>
The current elements of this iterable modified by toElement.
inherited
noSuchMethod(Invocation invocation)→ dynamic
Invoked when a nonexistent method or property is accessed.
inherited
reduce(E combine(E value, E element))→ E
Reduces a collection to a single value by iteratively combining elements of the collection using the provided function.
inherited
Removes entry from the linked list.
singleWhere(bool test(E element), {E orElse()?})→ E
The single element that satisfies test.
inherited
Creates an Iterable that provides all but the first count elements.
inherited
skipWhile(bool test(E value))→ Iterable<E>
Creates an Iterable that skips leading elements while test is satisfied.
inherited
Creates a lazy iterable of the count first elements of this iterable.
inherited
takeWhile(bool test(E value))→ Iterable<E>
Creates a lazy iterable of the leading elements satisfying test.
inherited
toList({bool growable = true})→ List<E>
Creates a List containing the elements of this Iterable.
inherited
Creates a Set containing the same elements as this iterable.
inherited
Returns a string representation of (some of) the elements of this.
inherited
where(bool test(E element))→ Iterable<E>
Creates a new lazy Iterable with all elements that satisfy the predicate test.
inherited
Creates a new lazy Iterable with all elements that have type T.
inherited
Operators
operator ==(Object other)→ bool
The equality operator.
inherited