SetBase class - dart:collection library

Base implementation of Set.

This class provides a base implementation of a Set that depends only on the abstract members: add, contains, lookup, remove, iterator, length and toSet.

Some of the methods assume that toSet creates a modifiable set. If using this base class for an unmodifiable set, where toSet should return an unmodifiable set, it's necessary to reimplement retainAll, union, intersection and difference.

Implementations of Set using this base should consider also implementing clear in constant time. The default implementation works by removing every element.

Implemented types
Implementers
Available extensions

Constructors

SetBase()

const

Properties

first → E
The first element.

no setteroverride

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>
An iterator that iterates over the elements of this set.

no setteroverride

last → E
The last element.

no setteroverride

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 elements in this Iterable.

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 → 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

wait Future<List<T>>

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

Waits for futures in parallel.

no setter

Methods

add(E value) bool
Adds value to the set.

override

addAll(Iterable<E> elements) → void
Adds all elements to this set.

override

any(bool test(E element)) bool
Checks whether any element of this iterable satisfies test.

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>() Set<R>
Provides a view of this set as a set of R instances.

override

clear() → void
Removes all elements from the set.

override

contains(Object? element) bool
Whether value is in the set.

override

containsAll(Iterable<Object?> other) bool
Whether this set contains all the elements of other.

override

difference(Set<Object?> other) Set<E>
Creates a new set with the elements of this that are not in other.

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 f(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

firstWhere(bool test(E value), {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 f(E element)) → void
Invokes action on each element of this iterable in iteration order.

override

intersection(Set<Object?> other) Set<E>
Creates a new set which is the intersection between this set and other.

override

join([String separator = ""]) String
Converts each element to a String and concatenates the strings.

override

lastWhere(bool test(E value), {E orElse()?}) → E
The last element that satisfies the given predicate test.

override

lookup(Object? element) → E?
If an object equal to object is in the set, return it.

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 value, E element)) → E
Reduces a collection to a single value by iteratively combining elements of the collection using the provided function.

override

remove(Object? value) bool
Removes value from the set.

override

removeAll(Iterable<Object?> elements) → void
Removes each element of elements from this set.

override

removeWhere(bool test(E element)) → void
Removes all elements of this set that satisfy test.

override

retainAll(Iterable<Object?> elements) → void
Removes all elements of this set that are not elements in elements.

override

retainWhere(bool test(E element)) → void
Removes all elements of this set that fail to satisfy test.

override

singleWhere(bool test(E value), {E orElse()?}) → E
The single element that satisfies test.

override

skip(int n) Iterable<E>
Creates an Iterable that provides all but the first count elements.

override

skipWhile(bool test(E value)) Iterable<E>
Creates an Iterable that skips leading elements while test is satisfied.

override

take(int n) Iterable<E>
Creates a lazy iterable of the count first elements of this iterable.

override

takeWhile(bool test(E value)) 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 with the same elements and behavior as this Set.

override

toString() String
A string representation of this object.

override

union(Set<E> other) Set<E>
Creates a new set which contains all the elements of this set and other.

override

where(bool f(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 ==(Object other) bool
The equality operator.

inherited

Static Methods

setToString(Set set) String
Converts a Set to a String.