Abstract implementation of a list.

ListBase can be used as a base class for implementing the List interface.

This class implements all read operations using only the length and operator[] and members. It implements write operations using those and add, length= and operator[]= Classes using this base class should implement those five operations.

NOTICE: For backwards compatibility reasons, there is a default implementation of add which only works for lists with a nullable element type. For list with a non-nullable element type, the add method must be implemented.

NOTICE: Forwarding just the four length and [] read/write operations to a normal growable List (as created by a [] literal) will give very bad performance for add and addAll operations of ListBase. These operations are implemented by increasing the length of the list by one for each add operation, and repeatedly increasing the length of a growable list is not efficient. To avoid this, override 'add' and 'addAll' to also forward directly to the growable list, or, if possible, use DelegatingList from "package:collection/collection.dart" instead of a ListMixin.

Implemented types

• List<E>

Implementers

• DomRectList
• DomStringList
• ElementList
• FileList
• HtmlCollection
• JsArray
• LengthList
• MimeTypeArray
• NodeList
• NumberList
• PluginArray
• SourceBufferList
• SpeechGrammarList
• StringList
• TextTrackCueList
• TextTrackList
• TouchList
• TransformList
• UnmodifiableListView

Available extensions

• EnumByName
• FutureIterable
• IterableExtensions
• ListToJSArray
• NullableIterableExtensions

Constructors

ListBase()

const

Properties

first ↔ E

The first element.

getter/setter pairoverride

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 setterinherited

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

Whether this collection has no elements.

no setteroverride

isNotEmpty → bool

Whether this collection has at least one element.

no setteroverride

iterator → Iterator<E>

A new Iterator that allows iterating the elements of this Iterable.

no setteroverride

last ↔ E

The last element.

getter/setter pairoverride

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

The number of objects in this list.

getter/setter pairinherited

nonNulls → Iterable<T>

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

The non-null elements of this iterable.

no setter

reversed → Iterable<E>

An Iterable of the objects in this list in reverse order.

no setteroverride

runtimeType → Type

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

singleOrNull → T?

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

The single element of this iterator, or null.

no setter

toJS → JSArray<T>

Available on List<T>, provided by the ListToJSArray extension

Converts this List to a JSArray by either casting, unwrapping, or cloning the List.

no setter

toJSProxyOrRef → JSArray<T>

Available on List<T>, provided by the ListToJSArray extension

Converts this List to a JSArray by either casting, unwrapping, or proxying the List.

no setter

wait → Future<List<T>>

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

Waits for futures in parallel.

no setter

Methods

add(E element) → void

Adds value to the end of this list, extending the length by one.

override

addAll(Iterable<E> iterable) → void

Appends all objects of iterable to the end of this list.

override

any(bool test(E element)) → bool

Checks whether any element of this iterable satisfies test.

override

asMap() → Map<int, E>

An unmodifiable Map view of this list.

override

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.

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>() → List<R>

Returns a view of this list as a list of R instances.

override

clear() → void

Removes all objects from this list; the length of the list becomes zero.

override

contains(Object? element) → bool

Whether the collection contains an element equal to element.

override

elementAt(int index) → E

Returns the indexth element.

override

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(E element)) → bool

Checks whether every element of this iterable satisfies test.

override

expand<T>(Iterable<T> f(E element)) → Iterable<T>

Expands each element of this Iterable into zero or more elements.

override

fillRange(int start, int end, [E? fill]) → void

Overwrites a range of elements with fillValue.

override

firstWhere(bool test(E element), {E orElse()?}) → E

The first element that satisfies the given predicate test.

override

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

override

followedBy(Iterable<E> other) → Iterable<E>

Creates the lazy concatenation of this iterable and other.

override

forEach(void action(E element)) → void

Invokes action on each element of this iterable in iteration order.

override

getRange(int start, int end) → Iterable<E>

Creates an Iterable that iterates over a range of elements.

override

indexOf(Object? element, [int start = 0]) → int

The first index of element in this list.

override

indexWhere(bool test(E element), [int start = 0]) → int

The first index in the list that satisfies the provided test.

override

insert(int index, E element) → void

Inserts element at position index in this list.

override

insertAll(int index, Iterable<E> iterable) → void

Inserts all objects of iterable at position index in this list.

override

join([String separator = ""]) → String

Converts each element to a String and concatenates the strings.

override

lastIndexOf(Object? element, [int? start]) → int

The last index of element in this list.

override

lastIndexWhere(bool test(E element), [int? start]) → int

The last index in the list that satisfies the provided test.

override

lastWhere(bool test(E element), {E orElse()?}) → E

The last element that satisfies the given predicate test.

override

map<T>(T f(E element)) → Iterable<T>

The current elements of this iterable modified by toElement.

override

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

reduce(E combine(E previousValue, E element)) → E

Reduces a collection to a single value by iteratively combining elements of the collection using the provided function.

override

remove(Object? element) → bool

Removes the first occurrence of value from this list.

override

removeAt(int index) → E

Removes the object at position index from this list.

override

removeLast() → E

Removes and returns the last object in this list.

override

removeRange(int start, int end) → void

Removes a range of elements from the list.

override

removeWhere(bool test(E element)) → void

Removes all objects from this list that satisfy test.

override

replaceRange(int start, int end, Iterable<E> newContents) → void

Replaces a range of elements with the elements of replacements.

override

retainWhere(bool test(E element)) → void

Removes all objects from this list that fail to satisfy test.

override

setAll(int index, Iterable<E> iterable) → void

Overwrites elements with the objects of iterable.

override

setRange(int start, int end, Iterable<E> iterable, [int skipCount = 0]) → void

Writes some elements of iterable into a range of this list.

override

shuffle([Random? random]) → void

Shuffles the elements of this list randomly.

override

singleWhere(bool test(E element), {E orElse()?}) → E

The single element that satisfies test.

override

skip(int count) → Iterable<E>

Creates an Iterable that provides all but the first count elements.

override

skipWhile(bool test(E element)) → Iterable<E>

Creates an Iterable that skips leading elements while test is satisfied.

override

sort([int compare(E a, E b)?]) → void

Sorts this list according to the order specified by the compare function.

override

sublist(int start, [int? end]) → List<E>

Returns a new list containing the elements between start and end.

override

take(int count) → Iterable<E>

Creates a lazy iterable of the count first elements of this iterable.

override

takeWhile(bool test(E element)) → Iterable<E>

Creates a lazy iterable of the leading elements satisfying test.

override

toList({bool growable = true}) → List<E>

Creates a List containing the elements of this Iterable.

override

toSet() → Set<E>

Creates a Set containing the same elements as this iterable.

override

toString() → String

A string representation of this object.

override

where(bool test(E element)) → Iterable<E>

Creates a new lazy Iterable with all elements that satisfy the predicate test.

override

whereType<T>() → Iterable<T>

Creates a new lazy Iterable with all elements that have type T.

override

Operators

operator +(List<E> other) → List<E>

Returns the concatenation of this list and other.

override

operator ==(Object other) → bool

The equality operator.

inherited

operator [](int index) → E

The object at the given index in the list.

inherited

operator []=(int index, E value) → void

Sets the value at the given index in the list to value.

inherited

Static Methods

listToString(List<Object?> list) → String

Converts a List to a String.