WeakHashSet<E extends Object> class

An unordered hash-table based Set implementation with weak referenced elements. An element in this weak hash set will be automatically removed when it is garbage collected. That is, when there is no other way for the program to access the weak referenced element, it is likely removed from this WeakHashSet anytime.

Note that the element object of type E must be a type that can be applied into WeakReference target. i.e. E must NOT be numbers, strings, booleans, records, null, dart:ffi pointers, dart:ffi structs, or dart:ffi unions.

Besides the weak referenced elements, the attributes of this WeakHashSet is the same to regular HashSet.

Mixed-in types
Available extensions

Constructors

WeakHashSet({bool equals(E, E)?, int hashCode(E)?, bool isValidKey(dynamic)?})
Create a hash set using the provided equals as equality.
WeakHashSet.from(Iterable elements)
Create a hash set containing all elements.
WeakHashSet.identity()
Creates an unordered identity-based set.
factory
WeakHashSet.of(Iterable<E> elements)
Create a hash set containing all elements.

Properties

first → E
The first element.
no setterinherited
hashCode → int
The hash code for this object.
no setterinherited
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 setterinherited
length → int
The number of elements in this Iterable.
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 setterinherited
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.
inherited
any(bool test(E 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.
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.
inherited
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.
inherited
difference(Set<Object?> other) → Set<E>
Creates a new set with the elements of this that are not in other.
inherited
elementAt(int index) → E
Returns the indexth element.
inherited
every(bool f(E element)) → bool
Checks whether every element of this iterable satisfies test.
inherited
expand<T>(Iterable<T> f(E element)) → Iterable<T>
Expands each element of this Iterable into zero or more elements.
inherited
firstWhere(bool test(E value), {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 f(E element)) → void
Invokes action on each element of this iterable in iteration order.
inherited
intersection(Set<Object?> other) → Set<E>
Creates a new set which is the intersection between this set and other.
inherited
join([String separator = ""]) → String
Converts each element to a String and concatenates the strings.
inherited
lastWhere(bool test(E value), {E orElse()?}) → E
The last element that satisfies the given predicate test.
inherited
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.
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
remove(Object? value) → bool
Removes value from the set.
override
removeAll(Iterable<Object?> elements) → void
Removes each element of elements from this set.
inherited
removeWhere(bool test(E element)) → void
Removes all elements of this set that satisfy test.
inherited
retainAll(Iterable<Object?> elements) → void
Removes all elements of this set that are not elements in elements.
inherited
retainWhere(bool test(E element)) → void
Removes all elements of this set that fail to satisfy test.
inherited
singleWhere(bool test(E value), {E orElse()?}) → E
The single element that satisfies test.
inherited
skip(int n) → Iterable<E>
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
take(int n) → Iterable<E>
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
toSet() → Set<E>
Creates a Set with the same elements and behavior as this Set.
override
toString() → String
A string representation of this object.
inherited
union(Set<E> other) → Set<E>
Creates a new set which contains all the elements of this set and other.
inherited
where(bool f(E element)) → Iterable<E>
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.
inherited