CountingHashSet<E> class Null safety

A HashSet that remembers how many times an element was added, and requires that element to be removed that many times before it's actually removed.

When elements are added, they replace existing equal elements (instead of doing nothing).

Implemented types
Mixed in types
Available Extensions

Constructors

CountingHashSet({bool equals(E, E)?, int hashCode(E)?, bool isValidKey(dynamic)?})
Equivalent to HashSet's main constructor.
CountingHashSet.identity()
Equivalent to HashSet.identity.
CountingHashSet.of(Iterable<E> elements)
Equivalent to HashSet.of.
factory

Properties

counts Map<E, int>
Values in the set, mapped to the number of times they've been added.
read-only
first → E
Returns the first element.
read-onlyoverride
hashCode int
The hash code for this object.
read-onlyinherited
isEmpty bool
Whether this collection has no elements.
read-onlyoverride
isNotEmpty bool
Whether this collection has at least one element.
read-onlyoverride
iterator Iterator<E>
An iterator that iterates over the elements of this set.
read-onlyoverride
last → E
Returns the last element.
read-onlyoverride
length int
Returns the number of elements in the iterable.
read-only
runtimeType Type
A representation of the runtime type of the object.
read-onlyinherited
single → E
Checks that this iterable has only one element, and returns that element.
read-onlyoverride

Methods

add(E value) bool
Adds value to the set.
override
addAll(Iterable<E> elements) → void
Adds all elements to this set.
inherited
addCounts(Map<E, int> counts) → void
Adds the given values with counts.
any(bool test(E element)) bool
Checks whether any element of this iterable satisfies test.
override
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
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
Returns 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>
Returns 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
Returns 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 non-existent 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.
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
Returns the single element that satisfies test.
override
skip(int n) Iterable<E>
Returns an Iterable that provides all but the first count elements.
override
skipWhile(bool test(E value)) Iterable<E>
Returns an Iterable that skips leading elements while test is satisfied.
override
take(int n) Iterable<E>
Returns a lazy iterable of the count first elements of this iterable.
override
takeWhile(bool test(E value)) Iterable<E>
Returns 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>
Returns a new lazy Iterable with all elements that satisfy the predicate test.
override
whereType<T>() Iterable<T>
Returns a new lazy Iterable with all elements that have type T.
override

Operators

operator ==(Object other) bool
The equality operator.
inherited