Deque<T> class

A double-ended queue (deque) that allows for insertion and deletion of elements at both the front and the rear.

This implementation uses ListQueue from dart:collection under the hood, which is designed to handle double-ended operations with very little friction.

Mixed-in types
Available extensions

Constructors

Deque()
Creates an empty deque.
Deque.from(Iterable<T> elements)
Creates a deque containing the elements of the given iterable.

Properties

first → T
The first element.
no setterinherited
firstOrNull → T?

Available on Iterable<T>, provided by the IterableExtensions extension

The first element of this iterator, or null if the iterable is empty.
no setter
hashCode → int
The hash code for this object.
no setteroverride
indexed → Iterable<(int, T)>

Available on Iterable<T>, provided by the IterableExtensions extension

Pairs of elements of the indices and elements of this iterable.
no setter
isEmpty → bool
Returns true if the deque is empty.
no setteroverride
isNotEmpty → bool
Returns true if the deque has at least one element.
no setteroverride
iterator → Iterator<T>
A new Iterator that allows iterating the elements of this Iterable.
no setteroverride
last → T
The last element.
no setterinherited
lastOrNull → T?

Available on Iterable<T>, provided by the IterableExtensions extension

The last element of this iterable, or null if the iterable is empty.
no setter
length → int
Returns the number of elements in the deque.
no setteroverride
nonNulls → Iterable<T>

Available on Iterable<T?>, provided by the NullableIterableExtensions extension

The non-null elements of this iterable.
no setter
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
single → T
Checks that this iterable has only one element, and returns that element.
no setterinherited
singleOrNull → T?

Available on Iterable<T>, provided by the IterableExtensions extension

The single element of this iterator, or null.
no setter
wait → Future<List<T>>

Available on Iterable<Future<T>>, provided by the FutureIterable extension

Waits for futures in parallel.
no setter

Methods

any(bool test(T element)) → bool
Checks whether any element of this iterable satisfies test.
inherited
asNameMap() → Map<String, T>

Available on Iterable<T>, provided by the EnumByName extension

Creates a map from the names of enum values to the values.
at(int index) → T
Random access: retrieves the element at index. Note: O(N) complexity due to underlying ListQueue implementation.
back() → T
Returns the back element without removing it (C++ STL naming).
byName(String name) → T

Available on Iterable<T>, provided by the EnumByName extension

Finds the enum value in this list with name name.
cast<R>() → Iterable<R>
A view of this iterable as an iterable of R instances.
inherited
clear() → void
Removes all elements from the deque.
contains(Object? element) → bool
Whether the collection contains an element equal to element.
inherited
deleteFront() → T
Removes and returns the element at the front of the deque. Throws a StateError if the deque is empty.
deleteLast() → T
Removes and returns the element at the last (rear) of the deque. Throws a StateError if the deque is empty.
elementAt(int index) → T
Returns the indexth element.
inherited
elementAtOrNull(int index) → T?

Available on Iterable<T>, provided by the IterableExtensions extension

The element at position index of this iterable, or null.
every(bool test(T element)) → bool
Checks whether every element of this iterable satisfies test.
inherited
expand<T>(Iterable<T> toElements(T element)) → Iterable<T>
Expands each element of this Iterable into zero or more elements.
inherited
firstWhere(bool test(T element), {T orElse()?}) → T
The first element that satisfies the given predicate test.
inherited
fold<T>(T initialValue, T combine(T previousValue, T element)) → T
Reduces a collection to a single value by iteratively combining each element of the collection with an existing value
inherited
followedBy(Iterable<T> other) → Iterable<T>
Creates the lazy concatenation of this iterable and other.
inherited
forEach(void action(T element)) → void
Invokes action on each element of this iterable in iteration order.
inherited
front() → T
Returns the front element without removing it (C++ STL naming).
getFront() → T
Returns the element at the front of the deque without removing it. Throws a StateError if the deque is empty.
getRear() → T
Returns the element at the rear (last) of the deque without removing it. Throws a StateError if the deque is empty.
insertFront(T element) → void
Inserts an element at the front of the deque.
insertLast(T element) → void
Inserts an element at the last (rear) of the deque.
join([String separator = ""]) → String
Converts each element to a String and concatenates the strings.
inherited
lastWhere(bool test(T element), {T orElse()?}) → T
The last element that satisfies the given predicate test.
inherited
map<T>(T toElement(T 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
popBack() → T
Removes and returns the back element (C++ STL naming).
popFront() → T
Removes and returns the front element (C++ STL naming).
pushBack(T element) → void
Adds an element to the back (C++ STL naming).
pushFront(T element) → void
Adds an element to the front (C++ STL naming).
reduce(T combine(T value, T element)) → T
Reduces a collection to a single value by iteratively combining elements of the collection using the provided function.
inherited
singleWhere(bool test(T element), {T orElse()?}) → T
The single element that satisfies test.
inherited
skip(int count) → Iterable<T>
Creates an Iterable that provides all but the first count elements.
inherited
skipWhile(bool test(T value)) → Iterable<T>
Creates an Iterable that skips leading elements while test is satisfied.
inherited
swap(Deque<T> other) → void
Exchanges the contents of this deque with those of other.
take(int count) → Iterable<T>
Creates a lazy iterable of the count first elements of this iterable.
inherited
takeWhile(bool test(T value)) → Iterable<T>
Creates a lazy iterable of the leading elements satisfying test.
inherited
toList({bool growable = true}) → List<T>
Creates a List containing the elements of this Iterable.
inherited
toSet() → Set<T>
Creates a Set containing the same elements as this iterable.
inherited
toString() → String
A string representation of this object.
override
where(bool test(T element)) → Iterable<T>
Creates a new lazy Iterable with all elements that satisfy the predicate test.
inherited
whereType<T>() → Iterable<T>
Creates a new lazy Iterable with all elements that have type T.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
override
operator [](int index) → T
Operator overload for random access.
operator []=(int index, T value) → void
Operator overload for setting an element at index. Note: O(N) complexity as it requires rebuilding parts of the queue.