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

Iterable<E>

Mixed-in types

UnmodifiableSetMixin<E>

Available extensions

Constructors

MapKeySet(Map<E, dynamic> _baseMap)

Properties

average → double: Available on Iterable<num>, provided by the IterableNumberExtension extension
The arithmetic mean of the elements of a non-empty iterable.
no setter
average → double: Available on Iterable<int>, provided by the IterableIntegerExtension extension
The arithmetic mean of the elements of a non-empty iterable.
no setter
first → E: The first element.
no setterinherited
firstOrNull → T?: Available on Iterable<T>, provided by the IterableExtension extension
The first element, or null if the iterable is empty.
no setter
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
flattened → Iterable<T>: Available on Iterable<Iterable<T>>, provided by the IterableIterableExtension extension
The sequential elements of each iterable in this iterable.
no setter
flattenedToList → List<T>: Available on Iterable<Iterable<T>>, provided by the IterableIterableExtension extension
The sequential elements of each iterable in this iterable.
no setter
flattenedToSet → Set<T>: Available on Iterable<Iterable<T>>, provided by the IterableIterableExtension extension
The unique sequential elements of each iterable in this iterable.
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 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
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
lastOrNull → T?: Available on Iterable<T>, provided by the IterableExtension extension
The last element, or null if the iterable is empty.
no setter
length → int: The number of elements in this Iterable.
no setter
max → int: Available on Iterable<int>, provided by the IterableIntegerExtension extension
A maximal element of the iterable.
no setter
max → double: Available on Iterable<double>, provided by the IterableDoubleExtension extension
A maximal element of the iterable.
no setter
max → num: Available on Iterable<num>, provided by the IterableNumberExtension extension
A maximal element of the iterable.
no setter
max → T: Available on Iterable<T>, provided by the IterableComparableExtension extension
A maximal element of the iterable.
no setter
maxOrNull → double?: Available on Iterable<double>, provided by the IterableDoubleExtension extension
A maximal element of the iterable, or null if the iterable is empty.
no setter
maxOrNull → int?: Available on Iterable<int>, provided by the IterableIntegerExtension extension
A maximal element of the iterable, or null if the iterable is empty.
no setter
maxOrNull → T?: Available on Iterable<T>, provided by the IterableComparableExtension extension
A maximal element of the iterable, or null if the iterable is empty.
no setter
maxOrNull → num?: Available on Iterable<num>, provided by the IterableNumberExtension extension
A maximal element of the iterable, or null if the iterable is empty.
no setter
min → double: Available on Iterable<double>, provided by the IterableDoubleExtension extension
A minimal element of the iterable.
no setter
min → T: Available on Iterable<T>, provided by the IterableComparableExtension extension
A minimal element of the iterable.
no setter
min → int: Available on Iterable<int>, provided by the IterableIntegerExtension extension
A minimal element of the iterable.
no setter
min → num: Available on Iterable<num>, provided by the IterableNumberExtension extension
A minimal element of the iterable.
no setter
minOrNull → double?: Available on Iterable<double>, provided by the IterableDoubleExtension extension
A minimal element of the iterable, or null it the iterable is empty.
no setter
minOrNull → int?: Available on Iterable<int>, provided by the IterableIntegerExtension extension
A minimal element of the iterable, or null it the iterable is empty.
no setter
minOrNull → T?: Available on Iterable<T>, provided by the IterableComparableExtension extension
A minimal element of the iterable, or null it the iterable is empty.
no setter
minOrNull → num?: Available on Iterable<num>, provided by the IterableNumberExtension extension
A minimal element of the iterable, or null it the iterable is empty.
no setter
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 setterinherited
singleOrNull → T?: Available on Iterable<T>, provided by the IterableExtension extension
The single element of the iterable, or null.
no setter
singleOrNull → T?: Available on Iterable<T>, provided by the IterableExtensions extension
The single element of this iterator, or null.
no setter
sum → int: Available on Iterable<int>, provided by the IterableIntegerExtension extension
The sum of the elements.
no setter
sum → num: Available on Iterable<num>, provided by the IterableNumberExtension extension
The sum of the elements.
no setter
sum → double: Available on Iterable<double>, provided by the IterableDoubleExtension extension
The sum of the elements.
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: 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
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<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
elementAtOrNull(int index) → T?: Available on Iterable<T>, provided by the IterableExtensions extension
The element at position index of this iterable, or null.
elementAtOrNull(int index) → T?: Available on Iterable<T>, provided by the IterableExtension extension
The indexth element, or null if there is no such element.
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
expandIndexed<R>(Iterable<R> expand(int index, T element)) → Iterable<R>: Available on Iterable<T>, provided by the IterableExtension extension
Expands each element and index to a number of elements in a new iterable.
firstWhere(bool test(E), {E orElse()?}) → E: The first element that satisfies the given predicate test.
inherited
firstWhereIndexedOrNull(bool test(int index, T element)) → T?: Available on Iterable<T>, provided by the IterableExtension extension
The first element whose value and index satisfies test.
firstWhereOrNull(bool test(T element)) → T?: Available on Iterable<T>, provided by the IterableExtension extension
The first element satisfying test, or null if there are none.
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
foldIndexed<R>(R initialValue, R combine(int index, R previous, T element)) → R: Available on Iterable<T>, provided by the IterableExtension extension
Combine the elements with a value and the current index.
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
forEachIndexed(void action(int index, T element)) → void: Available on Iterable<T>, provided by the IterableExtension extension
Takes an action for each element.
forEachIndexedWhile(bool action(int index, T element)) → void: Available on Iterable<T>, provided by the IterableExtension extension
Takes an action for each element and index as long as desired.
forEachWhile(bool action(T element)) → void: Available on Iterable<T>, provided by the IterableExtension extension
Takes an action for each element as long as desired.
groupFoldBy<K, G>(K keyOf(T element), G combine(G? previous, T element)) → Map<K, G>: Available on Iterable<T>, provided by the IterableExtension extension
Groups elements by keyOf then folds the elements in each group.
groupListsBy<K>(K keyOf(T element)) → Map<K, List<T>>: Available on Iterable<T>, provided by the IterableExtension extension
Groups elements into lists by keyOf.
groupSetsBy<K>(K keyOf(T element)) → Map<K, Set<T>>: Available on Iterable<T>, provided by the IterableExtension extension
Groups elements into sets by keyOf.
intersection(Set<Object?> other) → Set<E>: Returns a new set which is the intersection between this and other.
override
isSorted(Comparator<T> compare) → bool: Available on Iterable<T>, provided by the IterableExtension extension
Whether the elements are sorted by the compare ordering.
isSorted([Comparator<T>? compare]) → bool: Available on Iterable<T>, provided by the IterableComparableExtension extension
Whether the elements are sorted by the compare ordering.
isSortedBy<K extends Comparable<K>>(K keyOf(T element)) → bool: Available on Iterable<T>, provided by the IterableExtension extension
Whether the elements are sorted by their keyOf property.
isSortedByCompare<K>(K keyOf(T element), Comparator<K> compare) → bool: Available on Iterable<T>, provided by the IterableExtension extension
Whether the elements are compare-sorted by their keyOf property.
join([String separator = '']) → String: Converts each element to a String and concatenates the strings.
inherited
lastBy<K>(K key(T)) → Map<K, T>: Available on Iterable<T>, provided by the IterableExtension extension
Associates the elements in this by the value returned by key.
lastWhere(bool test(E), {E orElse()?}) → E: The last element that satisfies the given predicate test.
inherited
lastWhereIndexedOrNull(bool test(int index, T element)) → T?: Available on Iterable<T>, provided by the IterableExtension extension
The last element whose index and value satisfies test.
lastWhereOrNull(bool test(T element)) → T?: Available on Iterable<T>, provided by the IterableExtension extension
The last element satisfying test, or null if there are none.
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
mapIndexed<R>(R convert(int index, T element)) → Iterable<R>: Available on Iterable<T>, provided by the IterableExtension extension
Maps each element and its index to a new value.
none(bool test(T)) → bool: Available on Iterable<T>, provided by the IterableExtension extension
Whether no element satisfies test.
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
reduceIndexed(T combine(int index, T previous, T element)) → T: Available on Iterable<T>, provided by the IterableExtension extension
Combine the elements with each other and the current index.
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>
sample(int count, [Random? random]) → List<T>: Available on Iterable<T>, provided by the IterableExtension extension
Selects count elements at random from this iterable.
shuffled([Random? random]) → List<T>: Available on Iterable<T>, provided by the IterableExtension extension
Creates a shuffled list of the elements of the iterable.
singleWhere(bool test(E), {E orElse()?}) → E: The single element that satisfies test.
inherited
singleWhereIndexedOrNull(bool test(int index, T element)) → T?: Available on Iterable<T>, provided by the IterableExtension extension
The single element satisfying test.
singleWhereOrNull(bool test(T element)) → T?: Available on Iterable<T>, provided by the IterableExtension extension
The single element satisfying test.
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
slices(int length) → Iterable<List<T>>: Available on Iterable<T>, provided by the IterableExtension extension
Contiguous slices of this with the given length.
sorted(Comparator<T> compare) → List<T>: Available on Iterable<T>, provided by the IterableExtension extension
Creates a sorted list of the elements of the iterable.
sorted([Comparator<T>? compare]) → List<T>: Available on Iterable<T>, provided by the IterableComparableExtension extension
Creates a sorted list of the elements of the iterable.
sortedBy<K extends Comparable<K>>(K keyOf(T element)) → List<T>: Available on Iterable<T>, provided by the IterableExtension extension
Creates a sorted list of the elements of the iterable.
sortedByCompare<K>(K keyOf(T element), Comparator<K> compare) → List<T>: Available on Iterable<T>, provided by the IterableExtension extension
Creates a sorted list of the elements of the iterable.
splitAfter(bool test(T element)) → Iterable<List<T>>: Available on Iterable<T>, provided by the IterableExtension extension
Splits the elements into chunks after some elements.
splitAfterIndexed(bool test(int index, T element)) → Iterable<List<T>>: Available on Iterable<T>, provided by the IterableExtension extension
Splits the elements into chunks after some elements and indices.
splitBefore(bool test(T element)) → Iterable<List<T>>: Available on Iterable<T>, provided by the IterableExtension extension
Splits the elements into chunks before some elements.
splitBeforeIndexed(bool test(int index, T element)) → Iterable<List<T>>: Available on Iterable<T>, provided by the IterableExtension extension
Splits the elements into chunks before some elements and indices.
splitBetween(bool test(T first, T second)) → Iterable<List<T>>: Available on Iterable<T>, provided by the IterableExtension extension
Splits the elements into chunks between some elements.
splitBetweenIndexed(bool test(int index, T first, T second)) → Iterable<List<T>>: Available on Iterable<T>, provided by the IterableExtension extension
Splits the elements into chunks between some elements and indices.
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
whereIndexed(bool test(int index, T element)) → Iterable<T>: Available on Iterable<T>, provided by the IterableExtension extension
The elements whose value and index satisfies test.
whereNot(bool test(T element)) → Iterable<T>: Available on Iterable<T>, provided by the IterableExtension extension
The elements that do not satisfy test.
whereNotIndexed(bool test(int index, T element)) → Iterable<T>: Available on Iterable<T>, provided by the IterableExtension extension
The elements whose value and index do not satisfy test.
whereNotNull() → Iterable<T>: Available on Iterable<T?>, provided by the IterableNullableExtension extension
The non-null elements of this Iterable.
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

MapKeySet<E> class

Constructors

Properties

Methods

Operators

collection library