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> 
 
- Iterable<
- Mixed-in types
- Available extensions
- CartesianProductOnIterableExt
- ChunkedOnIterableExt
- EnumByName
- FutureIterable
- GenericTypeOnIterableExt
- IterableComparableExtension
- IterableDoubleExtension
- IterableExtension
- IterableExtensions
- IterableIntegerExtension
- IterableIterableExtension
- IterableNullableExtension
- IterableNumberExtension
- JoinWithLastSeparatorOnIterableExt
- MaybeAddToIterableExt
- MaybeAddToSetExt
- NullableIterableExtensions
- NullIfEmptyOnIterableExt
- NullIfEmptyOnSetExt
- TakeLastOnIterableExt
- ToMapOnIterableExt
- TryMergeOnIterableExt
- TryReduceOnIterableExt
- UniqueOnIterableExt
- UniqueOnMapEntryIterableExt
- UnmodifiableOnSetExt
- ValueOfOnEnumExtension
 
Properties
- average → double
- 
      Available on Iterable< The arithmetic mean of the elements of a non-empty iterable.int> , provided by the IterableIntegerExtension extensionno setter
- average → double
- 
      Available on Iterable< The arithmetic mean of the elements of a non-empty iterable.num> , provided by the IterableNumberExtension extensionno setter
- first → E
- 
  The first element.
  no setterinherited
- firstOrNull → T?
- 
      Available on Iterable< The first element, orT> , provided by the IterableExtension extensionnullif the iterable is empty.no setter
- firstOrNull → T?
- 
      Available on Iterable< The first element of this iterator, orT> , provided by the IterableExtensions extensionnullif the iterable is empty.no setter
- 
  flattened
  → Iterable<T> 
- 
      Available on Iterable< The sequential elements of each iterable in this iterable.Iterable< , provided by the IterableIterableExtension extensionT> >no setter
- 
  flattenedToList
  → List<T> 
- 
      Available on Iterable< The sequential elements of each iterable in this iterable.Iterable< , provided by the IterableIterableExtension extensionT> >no setter
- 
  flattenedToSet
  → Set<T> 
- 
      Available on Iterable< The unique sequential elements of each iterable in this iterable.Iterable< , provided by the IterableIterableExtension extensionT> >no setter
- genericType → Type
- 
      Available on Iterable< Returns the generic type of the iterable.T> , provided by the GenericTypeOnIterableExt extensionno setter
- hashCode → int
- 
  The hash code for this object.
  no setterinherited
- 
  indexed
  → Iterable<(int, T)> 
- 
      Available on Iterable< Pairs of elements of the indices and elements of this iterable.T> , provided by the IterableExtensions extensionno 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 Iteratorthat allows iterating the elements of thisIterable.no setterinherited
- last → E
- 
  The last element.
  no setterinherited
- lastOrNull → T?
- 
      Available on Iterable< The last element, orT> , provided by the IterableExtension extensionnullif the iterable is empty.no setter
- lastOrNull → T?
- 
      Available on Iterable< The last element of this iterable, orT> , provided by the IterableExtensions extensionnullif the iterable is empty.no setter
- length → int
- 
  The number of elements in this Iterable.
  no setter
- max → num
- 
      Available on Iterable< A maximal element of the iterable.num> , provided by the IterableNumberExtension extensionno setter
- max → T
- 
      Available on Iterable< A maximal element of the iterable.T> , provided by the IterableComparableExtension extensionno setter
- max → double
- 
      Available on Iterable< A maximal element of the iterable.double> , provided by the IterableDoubleExtension extensionno setter
- max → int
- 
      Available on Iterable< A maximal element of the iterable.int> , provided by the IterableIntegerExtension extensionno setter
- maxOrNull → num?
- 
      Available on Iterable< A maximal element of the iterable, ornum> , provided by the IterableNumberExtension extensionnullif the iterable is empty.no setter
- maxOrNull → double?
- 
      Available on Iterable< A maximal element of the iterable, ordouble> , provided by the IterableDoubleExtension extensionnullif the iterable is empty.no setter
- maxOrNull → T?
- 
      Available on Iterable< A maximal element of the iterable, orT> , provided by the IterableComparableExtension extensionnullif the iterable is empty.no setter
- maxOrNull → int?
- 
      Available on Iterable< A maximal element of the iterable, orint> , provided by the IterableIntegerExtension extensionnullif the iterable is empty.no setter
- min → double
- 
      Available on Iterable< A minimal element of the iterable.double> , provided by the IterableDoubleExtension extensionno setter
- min → T
- 
      Available on Iterable< A minimal element of the iterable.T> , provided by the IterableComparableExtension extensionno setter
- min → int
- 
      Available on Iterable< A minimal element of the iterable.int> , provided by the IterableIntegerExtension extensionno setter
- min → num
- 
      Available on Iterable< A minimal element of the iterable.num> , provided by the IterableNumberExtension extensionno setter
- minOrNull → T?
- 
      Available on Iterable< A minimal element of the iterable, orT> , provided by the IterableComparableExtension extensionnullit the iterable is empty.no setter
- minOrNull → int?
- 
      Available on Iterable< A minimal element of the iterable, orint> , provided by the IterableIntegerExtension extensionnullit the iterable is empty.no setter
- minOrNull → num?
- 
      Available on Iterable< A minimal element of the iterable, ornum> , provided by the IterableNumberExtension extensionnullit the iterable is empty.no setter
- minOrNull → double?
- 
      Available on Iterable< A minimal element of the iterable, ordouble> , provided by the IterableDoubleExtension extensionnullit the iterable is empty.no setter
- 
  nonNulls
  → Iterable<T> 
- 
      Available on Iterable< The non-T?> , provided by the NullableIterableExtensions extensionnullelements of this iterable.no setter
- 
  nullIfEmpty
  → Iterable<T> ?
- 
      Available on Iterable< Returns null if the Iterable is empty, otherwise returns the Iterable.T> , provided by the NullIfEmptyOnIterableExt extensionno setter
- 
  nullIfEmpty
  → Set<T> ?
- 
      Available on Set< Returns null if the Set is empty, otherwise returns the Set.T> , provided by the NullIfEmptyOnSetExt extensionno 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< The single element of this iterator, orT> , provided by the IterableExtensions extensionnull.no setter
- singleOrNull → T?
- 
      Available on Iterable< The single element of the iterable, orT> , provided by the IterableExtension extensionnull.no setter
- sum → double
- 
      Available on Iterable< The sum of the elements.double> , provided by the IterableDoubleExtension extensionno setter
- sum → num
- 
      Available on Iterable< The sum of the elements.num> , provided by the IterableNumberExtension extensionno setter
- sum → int
- 
      Available on Iterable< The sum of the elements.int> , provided by the IterableIntegerExtension extensionno setter
- 
  unmodifiable
  → Set<T> 
- 
      Available on Set< T> , provided by the UnmodifiableOnSetExt extensionno setter
- 
  wait
  → Future<List< T> >
- 
      Available on Iterable< Waits for futures in parallel.Future< , provided by the FutureIterable extensionT> >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< Creates a map from the names of enum values to the values.T> , provided by the EnumByName extension
- 
  byName(String name) → T 
- 
      Available on Iterable< Finds the enum value in this list with nameT> , provided by the EnumByName extensionname.
- 
  cartesianProduct(T combinator(T a, T b)) → Iterable< T> 
- 
      Available on Iterable< Creates the Cartesian product of the iterables and combines each resulting pair using theIterable< , provided by the CartesianProductOnIterableExt extensionT> >combinatorfunction.
- 
  cast<T> () → Set< T> 
- 
  A view of this iterable as an iterable of Rinstances.
- 
  chunked(int chunkSize) → Iterable< Iterable< T> >
- 
      Available on Iterable< Splits the Iterable into chunks of a maximum size specified byT> , provided by the ChunkedOnIterableExt extensionchunkSize.
- 
  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 thisthat are not inother.override
- 
  elementAt(int index) → E 
- 
  Returns the indexth element.inherited
- 
  elementAtOrNull(int index) → T? 
- 
      Available on Iterable< The element at positionT> , provided by the IterableExtensions extensionindexof this iterable, ornull.
- 
  elementAtOrNull(int index) → T? 
- 
      Available on Iterable< TheT> , provided by the IterableExtension extensionindexth element, ornullif 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< Expands each element and index to a number of elements in a new iterable.T> , provided by the IterableExtension extension
- 
  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< The first element whose value and index satisfiesT> , provided by the IterableExtension extensiontest.
- 
  firstWhereOrNull(bool test(T element)) → T? 
- 
      Available on Iterable< The first element satisfyingT> , provided by the IterableExtension extensiontest, ornullif 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< Combine the elements with a value and the current index.T> , provided by the IterableExtension extension
- 
  followedBy(Iterable< E> other) → Iterable<E> 
- 
  Creates the lazy concatenation of this iterable and other.inherited
- 
  forEach(void f(E)) → void 
- 
  Invokes actionon each element of this iterable in iteration order.inherited
- 
  forEachIndexed(void action(int index, T element)) → void 
- 
      Available on Iterable< Takes an action for each element.T> , provided by the IterableExtension extension
- 
  forEachIndexedWhile(bool action(int index, T element)) → void 
- 
      Available on Iterable< Takes an action for each element and index as long as desired.T> , provided by the IterableExtension extension
- 
  forEachWhile(bool action(T element)) → void 
- 
      Available on Iterable< Takes an action for each element as long as desired.T> , provided by the IterableExtension extension
- 
  groupFoldBy<K, G> (K keyOf(T element), G combine(G? previous, T element)) → Map< K, G> 
- 
      Available on Iterable< Groups elements byT> , provided by the IterableExtension extensionkeyOfthen folds the elements in each group.
- 
  groupListsBy<K> (K keyOf(T element)) → Map< K, List< T> >
- 
      Available on Iterable< Groups elements into lists byT> , provided by the IterableExtension extensionkeyOf.
- 
  groupSetsBy<K> (K keyOf(T element)) → Map< K, Set< T> >
- 
      Available on Iterable< Groups elements into sets byT> , provided by the IterableExtension extensionkeyOf.
- 
  intersection(Set< Object?> other) → Set<E> 
- 
  Returns a new set which is the intersection between thisandother.override
- 
  isSorted([Comparator< T> ? compare]) → bool
- 
      Available on Iterable< Whether the elements are sorted by theT> , provided by the IterableComparableExtension extensioncompareordering.
- 
  isSorted(Comparator< T> compare) → bool
- 
      Available on Iterable< Whether the elements are sorted by theT> , provided by the IterableExtension extensioncompareordering.
- 
  isSortedBy<K extends Comparable< (K> >K keyOf(T element)) → bool 
- 
      Available on Iterable< Whether the elements are sorted by theirT> , provided by the IterableExtension extensionkeyOfproperty.
- 
  isSortedByCompare<K> (K keyOf(T element), Comparator< K> compare) → bool
- 
      Available on Iterable< Whether the elements areT> , provided by the IterableExtension extensioncompare-sorted by theirkeyOfproperty.
- 
  join([String separator = '']) → String 
- 
  Converts each element to a String and concatenates the strings.
  inherited
- 
  joinWithLastSeparator({String separator = ', ', String lastSeparator = ' & '}) → String 
- 
      Available on Iterable, provided by the JoinWithLastSeparatorOnIterableExt extension Joins the elements of the iterable into a single string with the givenseparatorandlastSeparator. ThelastSeparatoris used to join the last two elements of the iterable.
- 
  lastBy<K> (K key(T)) → Map< K, T> 
- 
      Available on Iterable< Associates the elements inT> , provided by the IterableExtension extensionthisby the value returned bykey.
- 
  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< The last element whose index and value satisfiesT> , provided by the IterableExtension extensiontest.
- 
  lastWhereOrNull(bool test(T element)) → T? 
- 
      Available on Iterable< The last element satisfyingT> , provided by the IterableExtension extensiontest, ornullif 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< Maps each element and its index to a new value.T> , provided by the IterableExtension extension
- 
  maybeAdd(Set< T> ? add) → Set<T> 
- 
      Available on Set< AddsT> , provided by the MaybeAddToSetExt extensionaddto this its not null.
- 
  maybeAdd(Iterable< T> ? add) → Iterable<T> ?
- 
      Available on Iterable< AddsT> , provided by the MaybeAddToIterableExt extensionaddto this its not null.
- 
  none(bool test(T)) → bool 
- 
      Available on Iterable< Whether no element satisfiesT> , provided by the IterableExtension extensiontest.
- 
  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< Combine the elements with each other and the current index.T> , provided by the IterableExtension extension
- 
  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< SelectsT> , provided by the IterableExtension extensioncountelements at random from this iterable.
- 
  shuffled([Random? random]) → List< T> 
- 
      Available on Iterable< Creates a shuffled list of the elements of the iterable.T> , provided by the IterableExtension extension
- 
  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< The single element satisfyingT> , provided by the IterableExtension extensiontest.
- 
  singleWhereOrNull(bool test(T element)) → T? 
- 
      Available on Iterable< The single element satisfyingT> , provided by the IterableExtension extensiontest.
- 
  skip(int n) → Iterable< E> 
- 
  Creates an Iterable that provides all but the first countelements.inherited
- 
  skipWhile(bool test(E)) → Iterable< E> 
- 
  Creates an Iterablethat skips leading elements whiletestis satisfied.inherited
- 
  slices(int length) → Iterable< List< T> >
- 
      Available on Iterable< Contiguous slices ofT> , provided by the IterableExtension extensionthiswith the givenlength.
- 
  sorted([Comparator< T> ? compare]) → List<T> 
- 
      Available on Iterable< Creates a sorted list of the elements of the iterable.T> , provided by the IterableComparableExtension extension
- 
  sorted(Comparator< T> compare) → List<T> 
- 
      Available on Iterable< Creates a sorted list of the elements of the iterable.T> , provided by the IterableExtension extension
- 
  sortedBy<K extends Comparable< (K> >K keyOf(T element)) → List< T> 
- 
      Available on Iterable< Creates a sorted list of the elements of the iterable.T> , provided by the IterableExtension extension
- 
  sortedByCompare<K> (K keyOf(T element), Comparator< K> compare) → List<T> 
- 
      Available on Iterable< Creates a sorted list of the elements of the iterable.T> , provided by the IterableExtension extension
- 
  splitAfter(bool test(T element)) → Iterable< List< T> >
- 
      Available on Iterable< Splits the elements into chunks after some elements.T> , provided by the IterableExtension extension
- 
  splitAfterIndexed(bool test(int index, T element)) → Iterable< List< T> >
- 
      Available on Iterable< Splits the elements into chunks after some elements and indices.T> , provided by the IterableExtension extension
- 
  splitBefore(bool test(T element)) → Iterable< List< T> >
- 
      Available on Iterable< Splits the elements into chunks before some elements.T> , provided by the IterableExtension extension
- 
  splitBeforeIndexed(bool test(int index, T element)) → Iterable< List< T> >
- 
      Available on Iterable< Splits the elements into chunks before some elements and indices.T> , provided by the IterableExtension extension
- 
  splitBetween(bool test(T first, T second)) → Iterable< List< T> >
- 
      Available on Iterable< Splits the elements into chunks between some elements.T> , provided by the IterableExtension extension
- 
  splitBetweenIndexed(bool test(int index, T first, T second)) → Iterable< List< T> >
- 
      Available on Iterable< Splits the elements into chunks between some elements and indices.T> , provided by the IterableExtension extension
- 
  take(int n) → Iterable< E> 
- 
  Creates a lazy iterable of the countfirst elements of this iterable.inherited
- 
  takeLast(int count) → Iterable< T> 
- 
      Available on Iterable< T> , provided by the TakeLastOnIterableExt extension
- 
  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
- 
  toMap() → Map< K, V> 
- 
      Available on Iterable< Converts an iterable of MapEntry to a Map.MapEntry< , provided by the ToMapOnIterableExt extensionK, V> >
- 
  toSet() → Set< E> 
- 
  Creates a Set containing the same elements as this iterable.
  inherited
- 
  toString() → String 
- A string representation of this object.
- 
  tryMerge([Iterable< T> merge(Iterable<T> ?, Iterable<T> ?)?]) → Iterable<T> ?
- 
      Available on Iterable< Tries to merge the iterables, returning null if it fails.Iterable< , provided by the TryMergeOnIterableExt extensionT> ?>
- 
  tryReduce(T combine(T, T)) → T? 
- 
      Available on Iterable< Tries to reduce the iterable, returning null if it fails.T> , provided by the TryReduceOnIterableExt extension
- 
  union(Set< E> other) → Set<E> 
- 
  Returns a new set which contains all the elements of thisandother.override
- 
  unique([bool equals(T a, T b)?]) → Iterable< T> 
- 
      Available on Iterable< Returns a new iterable with all duplicate elements removed.T> , provided by the UniqueOnIterableExt extension
- 
  uniqueEntries() → List< MapEntry< K, V> >
- 
      Available on Iterable< Returns only the unique entries in the iterable.MapEntry< , provided by the UniqueOnMapEntryIterableExt extensionK, V> >
- 
  uniqueKeys() → List< MapEntry< K, V> >
- 
      Available on Iterable< Returns only the entries with unique keys in the iterable.MapEntry< , provided by the UniqueOnMapEntryIterableExt extensionK, V> >
- 
  uniqueValues() → List< MapEntry< K, V> >
- 
      Available on Iterable< Returns only the entries with unique values in the iterable.MapEntry< , provided by the UniqueOnMapEntryIterableExt extensionK, V> >
- 
  valueOf(String? value) → T? 
- 
      Available on Iterable< Returns the enum value from this iterable that matches the given stringT> , provided by the ValueOfOnEnumExtension extensionvalue.
- 
  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< The elements whose value and index satisfiesT> , provided by the IterableExtension extensiontest.
- 
  whereNot(bool test(T element)) → Iterable< T> 
- 
      Available on Iterable< The elements that do not satisfyT> , provided by the IterableExtension extensiontest.
- 
  whereNotIndexed(bool test(int index, T element)) → Iterable< T> 
- 
      Available on Iterable< The elements whose value and index do not satisfyT> , provided by the IterableExtension extensiontest.
- 
  whereNotNull() → Iterable< T> 
- 
      Available on Iterable< The non-T?> , provided by the IterableNullableExtension extensionnullelements of thisIterable.
- 
  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