MapKeySet<E> class

An unmodifiable Set view of the keys of a Map.

The set delegates all operations to the underlying map.

A Map can only contain each key once, so its keys can always be viewed as a Set without any loss, even if the Map.keys getter only shows an Iterable view of the keys.

Note that lookup is not supported for this set.

Implemented types
Mixed-in types
Available extensions

Constructors

MapKeySet(Map<E, dynamic> _baseMap)

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 setter
isNotEmpty → bool
Whether this collection has at least one element.
no setter
iterator → Iterator<E>
A new Iterator that allows iterating the elements of this Iterable.
no setterinherited
last → E
The last element.
no setterinherited
length → int
The number of elements in 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 setterinherited

Methods

add(E value) → bool
Throws an UnsupportedError; operations that change the set are disallowed.
inherited
addAll(Iterable<E> elements) → void
Throws an UnsupportedError; operations that change the set are disallowed.
inherited
any(bool test(E)) → bool
Checks whether any element of this iterable satisfies test.
inherited
cast<T>() → Set<T>
A view of this iterable as an iterable of R instances.
clear() → void
Throws an UnsupportedError; operations that change the set are disallowed.
inherited
contains(Object? element) → bool
Whether the collection contains an element equal to element.
containsAll(Iterable<Object?> other) → bool
Whether this set contains all the elements of other.
override
difference(Set<Object?> other) → Set<E>
Returns a new set with the the elements of this that are not in other.
override
elementAt(int index) → E
Returns the indexth element.
inherited
every(bool test(E)) → bool
Checks whether every element of this iterable satisfies test.
inherited
expand<T>(Iterable<T> f(E)) → Iterable<T>
Expands each element of this Iterable into zero or more elements.
inherited
firstWhere(bool test(E), {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)) → void
Invokes action on each element of this iterable in iteration order.
inherited
intersection(Set<Object?> other) → Set<E>
Returns a new set which is the intersection between this and other.
override
join([String separator = '']) → String
Converts each element to a String and concatenates the strings.
inherited
lastWhere(bool test(E), {E orElse()?}) → E
The last element that satisfies the given predicate test.
inherited
lookup(Object? element) → E
Throws an UnsupportedError since there's no corresponding method for Maps.
override
map<T>(T f(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
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
Throws an UnsupportedError; operations that change the set are disallowed.
inherited
removeAll(Iterable elements) → void
Throws an UnsupportedError; operations that change the set are disallowed.
inherited
removeWhere(bool test(E)) → void
Throws an UnsupportedError; operations that change the set are disallowed.
inherited
retainAll(Iterable elements) → void
Throws an UnsupportedError; operations that change the set are disallowed.
inherited
retainWhere(bool test(E)) → void
Throws an UnsupportedError; operations that change the set are disallowed.
inherited
retype<T>() → Set<T>
singleWhere(bool test(E), {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)) → 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)) → 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 containing the same elements as this iterable.
inherited
toString() → String
A string representation of this object.
union(Set<E> other) → Set<E>
Returns a new set which contains all the elements of this and other.
override
where(bool test(E)) → 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